The Steampunk Forum at Brass Goggles

Welcome to the Guild of Icarus, I am your host J. Wilhelm under the assumed title of "Keeper of the Guild, Maestro Dio*." The Guild of Icarus is a club for all people interested in all matters related to Aeronautical and Space Flight, including engineering as well as aviation.

My interest in the subject arises from my studies at the University of Texas, where I obtained the degrees of BSc and MSc in Aerospace Engineering (Concentrations in Atmospheric Flight and Hypersonic Aerothermodynamics, respectively).


Alas, I never have been able to practice my knowldege on account of devastating events in my life which were completely out of my control. I have now lost well over a decade of my life after I left school (not counting my 3rd attempt at a PhD in 2005). As I ponder now in my middle age whether I can even go back to this field, I now have decided to at least start exercising my neurons, and naturally I need an outlet. This is another reason for starting The Guild.

A third reason for starting the guild, is completeness. If I just pepper monologues on the subject all over Brassgoggles, you will be getting a very skewed image of what flight is. I am heavy on the science, but I should note that Pilots and Engineers effectively "speak two different languages," as designing a machine, and flying it are two completely different things. I have found out that we have at least a couple of pilots in the forum. I'd be very interested to see what they can bring to the table.

My only experience with practical flight is limited to a very old mechanical Link-GAT-1 flight simulator (Cessna 150) that I used to study flight performance at college back in the 1990s. Honestly, if you saw the flight simulator, you might think that there was a coin slot on the side and a sign which read "Rides 25¢" and that we stole it from a local supermarket.  ;D

~ ~ ~

So let the games begin.... Make a suggestion for a topic! There will be no bars on the subject - the discussion can be as technical or whimsical as you want, just remember that if you have some knowledge others lack, then you assume the role of the teacher, and your responsibility is to make the subject tractable to all who read this thread. Do you have science you want to discuss? Bring it forth. Do you have nice fantasy illustrations you want to show? Bring them forth. This is a place for people who like flight.  It will all be appreciated.

Naturally lighter than air flying machines such as airships and balloons are included , but if you read the history on aeronautics, you may find out that the field is actually very old, as human beings have been trying to achieve flight for a very long time, indeed!

It is not at all impossible that heavier than air machines could have taken flight before the balloon and airship, though we, Steampunk, are rather obsessed with airships. I was very surprised as a young student to discover that even before heavier than air flight was achieved, scientists were already delving into areas of study that we only associate with technology from the 20th. C, more akin to what we see in the movie "The Right Stuff."

As it happens, this being a Steampunk forum, Victorian Era scientists were busy developing the science that people would use to develop supersonic flight. They could not implement the technology, because the truth is that the development of Fluid Mechanics as a field in Mechanical Engineering, was a slow, tortuous and haphazard affair, more like Frankenstein Monster of events, mostly made in the lab, that did not make much sense until after the turn of the 19th. C.  But all the tools for flight were already in place by the middle of the 19th. C.  I'll rant more about that the next time I return...



*EDITED to keep consistency with the title used in Last Exile

Tagging this to follow the thread.

Dear Admiral Wilhelm,
I do like your VTOL design; in horizontal flight would the forward jets have been passive to avoid 'cooking' the fuselage? I know this is a question that has recently been raised for Skylon, and it may be that if that craft is ever made there will need to be some active cooling (i.e. dumping water over the skin) to avoid the sabre engines scorching its rear half.

Anyway, my thoughts on Steampunk supersonic flight. As shown in your picture, a bullet shape is nice and stable (if spinning) in flight, so let's go Jules Verne (or possibly Gerald Bull - https://en.wikipedia.org/wiki/Gerald_Bull (https://en.wikipedia.org/wiki/Gerald_Bull)) and do a sub-orbital by putting our passengers in a glorified shell. But what of the problem of squishing them to a thin red smear by the launch force? Well, I was watching a documentary a little while ago about one of Hitler's V-weapons that never saw service - a supergun that would have used staged explosions along the launch tube to accelerate the projectile. So, I'm thinking a massive launch tube (laid along the side of some convenient mountain), our intrepid aeronaut's capsule accelerated at multiple stages to keep down to say 4g max. I'll have to play with some numbers when I get a few moments to see if it might be feasible.

Yours,
Miranda.

Regarding the above, I've been trying to ascertain how Verne's astronauts survived their (literal) moonshot. Would it have been possible (hypothetically, of course) for the astronaut's compartment to have remained stable/stationary through some sort of gyroscopic (or other) method while the outer shell did all the spinning, thus sparing the organic material inside from becoming wet little pancakes?

Quote from: Miranda.T on October 05, 2015, 06:44:54 PM
Dear Admiral Wilhelm,
I do like your VTOL design; in horizontal flight would the forward jets have been passive to avoid 'cooking' the fuselage? I know this is a question that has recently been raised for Skylon, and it may be that if that craft is ever made there will need to be some active cooling (i.e. dumping water over the skin) to avoid the sabre engines scorching its rear half.

Anyway, my thoughts on Steampunk supersonic flight. As shown in your picture, a bullet shape is nice and stable (if spinning) in flight, so let's go Jules Verne (or possibly Gerald Bull - https://en.wikipedia.org/wiki/Gerald_Bull (https://en.wikipedia.org/wiki/Gerald_Bull)) and do a sub-orbital by putting our passengers in a glorified shell. But what of the problem of squishing them to a thin red smear by the launch force? Well, I was watching a documentary a little while ago about one of Hitler's V-weapons that never saw service - a supergun that would have used staged explosions along the launch tube to accelerate the projectile. So, I'm thinking a massive launch tube (laid along the side of some convenient mountain), our intrepid aeronaut's capsule accelerated at multiple stages to keep down to say 4g max. I'll have to play with some numbers when I get a few moments to see if it might be feasible.

Yours,
Miranda.

Fortunately,  there is enough distance between the engine cowls and the fuselage, especially at speed. Jet engines can get very close to the fuselage (remember the de Havilland Comet?).  I knew about the active hydrogen cooling for the skin, and the helium cooling for the compressor,  but never heard about issues with nozzle exhaust heat transfer to the fuselage... Do you have a specific source that details this design problem?  

The SABRE engine is basically a hydrogen + liquid oxygen rocket, with the exception that below a certain speed, you are compressing air from the environment to get the oxygen. Conventionally I'd think there is a huge difference between the heat transfer in the vicinity of a rocket nozzle exhaust and a turbo jet exhaust. In the rocket nozzle you're also having to deal with intense radiative heat transfer.


For the VTOL tilt Propfan that was one of the concerns we needed to address early on.  But the real risk is to the tarmac upon takeoff  ;D That is a problem my team didn't tackle, and we just assumed the landing facilities (pad) would be redesigned accordingly. We also assumed that the use of Propfans would reduce the hot jet exhaust.

A propfan is basically a supersonic propeller,  either directly attached to the turbine rotor (Unducted Fan),  or attached by gears like a regular turboprop. The idea was to "feather" the props at altitude when all of that thrust wasn't needed. The complications, of course,  included turbulence from the propellers,  but otherwise it helped you to extract as much heat from the turbine as possible and channel it to the propfan.  Cooler and more efficient thrust.


We had to comply with several US Federal Aviation Requirements including FAR 25 for jetliner,  and FAR 29 for heavy rotorcraft (helicopters). It needed to survive an engine failure (nearly impossible to achieve in tilt rotor craft), and I needed to come with a climb and descent path that satisfied both types of craft. I didn't care much for the airport facilities as I was too busy designing a flight path just to satisfy FAR statutes (no other team needed to do this but was a condition imposed by the professor as FAR were part of the test).  In the real world,  FAA requirements would have to be adjusted to tilt rotorcraft to make more sense.

This project was my baby, so to speak, and I had two other ten members with me leading the group.

~ ~ ~ ~ ~ ~


Actually I'm sure the ballistic missile approach has been suggested before, but in combination of rockets for more delicate payloads :

From the same Wiki article on Gerald Bull

Quote
The ultimate goal of the program was the Martlet-4, a three-stage 16.4" rocket that would be fired from a lengthened gun at Barbados and would reach orbit. In 1964 Donald Mordell was able to convince the Canadian government of the value of the HARP project as a low-cost method for Canada to enter the space-launch business, and arranged a joint Canadian-US funding program of $3 million a year for three years, with the Canadians supplying $2.5 million of that. Another 16.4" gun, mounted horizontally, was being tested at the Highwater range, and was extended by cutting the breech off the end of one gun and welding it to the end of another to produce a new gun over 110 feet long. The extension allowed the powder to be contained for a longer period of time, slowing down the acceleration and loads on the airframe, while also offering higher overall performance. Once the system had been tested at Highwater, a second barrel was shipped to Foul Bay, attached and strengthened with external bracing to allow it to be raised from the horizontal. This gun was extensively tested in 1965 and 66.

What you want is to achieve orbital speed without exceeding the human ability to take acceleration.  Rockets might still have dominated the thinking, though. It's one of those things that could have been done earlier, and the stability issue being practically solved by a cannon bore or helical rail.

Quote from: GCCC on October 05, 2015, 10:09:17 PM
Regarding the above, I've been trying to ascertain how Verne's astronauts survived their (literal) moonshot. Would it have been possible (hypothetically, of course) for the astronaut's compartment to have remained stable/stationary through some sort of gyroscopic (or other) method while the outer shell did all the spinning, thus sparing the organic material inside from becoming wet little pancakes?

Rotational inertia will demand a much slower rotation rate for a larger diameter cylinder and mass, so I don't think that centripetal acceleration would reduce the occupants to wet little red pancakes. The pancake syndrome comes mostly from the linear acceleration needed to reach muzzle velocity. There would be however, severe problems with orientation, and balance in the human body,  and as you suggested,  you need to come up with a solution like an inner chamber perhaps.

Satellite Launch (http://youtube.com/watch?v=sr2JPD-hGjQ#)

Quote from: J. Wilhelm on October 06, 2015, 01:18:58 AM
(snip)
Fortunately,  there is enough distance between the engine cowls and the fuselage, especially at speed. Jet engines can get very close to the fuselage (remember the de Havilland Comet?).  I knew about the active hydrogen cooling for the skin, and the helium cooling for the compressor,  but never heard about issues with nozzle exhaust heat transfer to the fuselage... Do you have a specific source that details this design problem?  
(snip)

Details are here http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150015818.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150015818.pdf) with a discussion here http://forum.nasaspaceflight.com/index.php?topic=36826.msg1415833#msg1415833 (http://forum.nasaspaceflight.com/index.php?topic=36826.msg1415833#msg1415833).

As to the Vern inspired capsule, I was always just so impressed as to how close he was to the actual Apollo launches - pretty much the same launch location, his capsule was about the size of Apollo, the transit time to lunar orbit was correct; impressive prescience. As for the capsule spin, with clever design a little but of (simulated) microgravity could be beneficial, although as you say looking out of any windows would be very disorientating...

Yours,
Miranda.

Quote from: Miranda.T on October 06, 2015, 06:01:14 PM

Quote from: J. Wilhelm on October 06, 2015, 01:18:58 AM
(snip)
Fortunately,  there is enough distance between the engine cowls and the fuselage, especially at speed. Jet engines can get very close to the fuselage (remember the de Havilland Comet?).  I knew about the active hydrogen cooling for the skin, and the helium cooling for the compressor,  but never heard about issues with nozzle exhaust heat transfer to the fuselage... Do you have a specific source that details this design problem?  
(snip)

Details are here http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150015818.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20150015818.pdf) with a discussion here http://forum.nasaspaceflight.com/index.php?topic=36826.msg1415833#msg1415833 (http://forum.nasaspaceflight.com/index.php?topic=36826.msg1415833#msg1415833).

As to the Vern inspired capsule, I was always just so impressed as to how close he was to the actual Apollo launches - pretty much the same launch location, his capsule was about the size of Apollo, the transit time to lunar orbit was correct; impressive prescience. As for the capsule spin, with clever design a little but of (simulated) microgravity could be beneficial, although as you say looking out of any windows would be very disorientating...

Yours,
Miranda.

Thank you.  I downloaded the AIAA paper (My technical communication professor back in college would have a field day with these workers' writing skills). I'll be taking a look at it later today.

It looks from the abstract that they're talking about the rocket plume, the performance of SABRE and it's effect on Skylon's fuselage.

"Underexpanded" in this case refers to the pressure and speed of the rocket nozzle exhaust.  A rocket nozzle is basically a converging-diverging duct where the speed of gases increases from subsonic at the combustion chamber, before reaching the "throat" of the duct (at which point the flow travels at the speed of sound), and subsequently accelerate throghout the "Bell",  which is what everyone sees in a rocket engine, such that the gases have reached supersonic speeds.

As the gases travel from the combustion chamber through the throat into the bell,  they're expanding (literally),  and in doing so,  they're accelerating.  There's a 1-1 relationship between diverging nozzle diameter (as function of distance along axis of nozzle) and the supersonic Mach number and pressure of the gases.  So you design the bell to expand the gases,  ideally to equalize the gas pressure to ambient pressure (giving you a particular Mach number at the outlet, so there's a given maximum bell diameter for a particular barometric "design"  altitude,  and at any other altitude the bell either exhausts gases over the ambient pressure (under expanded), or below ambient pressure (over expanded).  If underexpanded or overextended,  you get trailing expansion and compression (shock) waves, which waste energy into the environment.

In this case they're categorizing the exhaust as unexpectedly Underexpanded,  but mysteriously they're linking that to "favorable" lift to drag ratio of the body? ???  :D so their writing skills are not so good. The abstract sucks  :D

In reading the article I'll find out exactly what they mean  ;D

If I remember correctly, there was work ongoing to try to optimise the nozzle shape, but given the range of speeds and conditions that's clearly not a trivial task. At one point I think they were looking at a variable nozzle geometry but if I'm interpreting the current reports correctly that idea seems to have been dropped.

Yours,
Miranda.

Quote from: Miranda.T on October 07, 2015, 05:27:31 PM
If I remember correctly, there was work ongoing to try to optimise the nozzle shape, but given the range of speeds and conditions that's clearly not a trivial task. At one point I think they were looking at a variable nozzle geometry but if I'm interpreting the current reports correctly that idea seems to have been dropped.

Yours,
Miranda.

This is just the nature of the beast, I'm afraid. I still have to find the time to read the article, but on the surface, and falling to classical theory, conventional bell (converging diverging) nozzles are naturally "tuned" to one pressure only and you usually design at which optimal altitude you'll get the cleanest output. Variable nozzles exist, but they're heavy.

My impression so far:

Superficially it sounds to me like they wanted to adjust the optimal design altitude on the rocket nozzles (which would be easy enough to fix), but it may turn out that that no amount of tinkering with the design altitude of the nozzle is good enough to prevent excessive heat transfer from the rocket plume to the fuselage, for the simple fact that the optimal design altitude range (cleanest output) is just very narrow.

Like a radio tuning to a radio station, which filters the radio frequencies to a narrow band and only one radio station passes through. Similarly, the rocket nozzle restricts the output pressure to a very narrow range with a single design altitude.  It's the nature of the beast.

I guess you could attempt to "widen" the peak performance range of the nozzles, to accommodate the fact that your fluid dynamics around the fuselage is a bit "off" ...  by way of "more favourable lift to drag ratios," ::)  which to me simply sounds like a very indirect, roundabout way of saying that the layers of air next to the fuselage are faster that expected, and thus thinner than expected (possibly a thinner boundary layer), thus allowing the rocket plumes to get closer to the fuselage. I won't know until I read more of the paper. The boundary layer over the fuselage is no "protection" against rocket plumes.

This is the result of the design geometry they chose. The side by side engine pod design is to blame here IMHO.  They need to re-design the engine pods AND re-position the engines.

The X-33 prototype by Skunk Works used an "aerospike" in the back, instead of a bell. If you're willing to sacrifice maximum performance at a particular altitude (that is at a particular ambient pressure), you can actually get a wider range of altitudes by - literally- turning the bell nozzle inside out.


In an aerospike, you let the atmosphere act like a "soft wall" to the expanding plume of gases, dowstream from the "throat" of the nozzle, using just a central cone or ramp to provide the "bell" curved shape to expand the gases (remember expansion <=> speeding up), and in doing so you get a lower maximum peak performance at design altitude, but a relatively high performance spread over a much wider range of altitudes (like the radio circuit having a "wide" tuning circuit and accepting several radio stations at once).  Such that the overall performance of the rocket is higher, from launch to the maximum design altitude.


The problem with aeropikes is that when it comes to exhaust plumes, they are much worse. The "soft air wall" around the plume does a very poor job of containing the plume itself and does not block radiative (infra-red) heat at all.  Aerospikes allow wider plumes, and thus the fuselage would get a harder hit. So aerospikes are not the solution for side by side engine pods.  

The engine needs to be placed centrally and in the back of the vehicle like on the X-33. Or if I ignore the concentric bleed design, and imagine converting the engine geometry to a planar orientation, taking the SABRE compressors and aligning them along the aerospike ramp, in rectangular engine pods, orienting the  aerospike ramps along the back such that they direct the plumes away from the fuselage (say in the "up/down" directions). That could greatly reduce the risk to the fuselage. There is a price to pay, as the rectangular geometry for supersonic expansion or compression ramps is always less efficient than conical ones.

I don't want to lose the lay reader on what we're talking about, though... we are reaching a critical point with a lot of physics and I haven't even read the article yet  ;D

For those who are a bit lost, but would like to search, here is a "glossary" or "summary" of the physics subjects covered so far, which you can Google on the Internet:





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Quote from: J. Wilhelm on October 09, 2015, 09:40:15 AM
(snip)
The engine needs to be placed centrally and in the back of the vehicle like on the X-33. Or if I ignore the concentric bleed design, and imagine converting the engine geometry to a planar orientation, taking the SABRE compressors and aligning them along the aerospike ramp, in rectangular engine pods, orienting the  aerospike ramps along the back such that they direct the plumes away from the fuselage (say in the "up/down" directions). That could greatly reduce the risk to the fuselage. There is a price to pay, as the rectangular geometry for supersonic expansion or compression ramps is always less efficient than conical ones.
(snip)

Ah, but there is no choice in having the engines neat the centre of gravity for this type of craft (or so REL believe). What killed the HOTOL project (https://en.wikipedia.org/wiki/HOTOL (https://en.wikipedia.org/wiki/HOTOL)) back in the '80s was the choice of rear-mounted engine; it caused (in simulation) so massive a turning moment they would have needed to add so much weight to compensate that the payload to LEO would have been down to about two tonnes. Also they were (apparently) having issues with HOTOL's separation of centre of pressure and centre of gravity. So, the solution seems to be engines mounted near the COG and they'll just have to find some fix for the fuselage heating.

Yours,
Miranda.

Quote from: Miranda.T on October 09, 2015, 05:22:27 PM

Quote from: J. Wilhelm on October 09, 2015, 09:40:15 AM
(snip)
The engine needs to be placed centrally and in the back of the vehicle like on the X-33. Or if I ignore the concentric bleed design, and imagine converting the engine geometry to a planar orientation, taking the SABRE compressors and aligning them along the aerospike ramp, in rectangular engine pods, orienting the  aerospike ramps along the back such that they direct the plumes away from the fuselage (say in the "up/down" directions). That could greatly reduce the risk to the fuselage. There is a price to pay, as the rectangular geometry for supersonic expansion or compression ramps is always less efficient than conical ones.
(snip)

Ah, but there is no choice in having the engines neat the centre of gravity for this type of craft (or so REL believe). What killed the HOTOL project (https://en.wikipedia.org/wiki/HOTOL (https://en.wikipedia.org/wiki/HOTOL)) back in the '80s was the choice of rear-mounted engine; it caused (in simulation) so massive a turning moment they would have needed to add so much weight to compensate that the payload to LEO would have been down to about two tonnes. Also they were (apparently) having issues with HOTOL's separation of centre of pressure and centre of gravity. So, the solution seems to be engines mounted near the COG and they'll just have to find some fix for the fuselage heating.

Yours,
Miranda.

My fault. I think we are talking about two different things here. The X-33 is a rocket glider, it ascends like a rocket through the atmosphere without using aerodynamic lift along the way, and returns to earth as an unpowered hypersonic glider, and so stability issues are limited to dynamic axis and engine thrust vector alignment...

Whereas the HOTOL and SKYLON are space planes or better stated space airplanes, with "airplane" being the operative word here. This there are stability concerns regarding the position of the dynamic centre (as a function of speed) in relation to the centre of gravity for horizontal flight into orbit.

This is basically an Aircraft Sizing problem (preliminary design). For positive stability, the dynamic centre (centre of all forces including drag, lift and thrust) must lie behind the gravitational centre, which in this case as you say moves aft a little too far back, pushing the dynamic centre too far back (and it moves back further at greater speeds).  For example, in the drawing of my Zarquon Tilt Propfan above, the wing hadn't been - at the time I made that drawing - fixed in the right location.

I think the HOTOL designers had to go through the surprise that their structure was grossly unbalanced after positioning the lifting surfaces (similar to Space Shuttle) , and needed a lot of actuator force and structure to balance it right during flight (I have NOT read any literature on what actually happened - I'm just guessing here based on what I know and the clues you give me).

However, having stated that above, I have seen greater hurdles overcome, and this seems a problem specific to a particular design with particular engine setup and chosen fuselage/wing materials.

Note that in Hypersonic aircraft designs there is an equivalence between the shape or "style" of the vehicle, and the materials used for the airplane's skin. The reason being that a sharp, elongated idealised supersonic, needle/arrow shape design, while being less draggy, and reducing the intensity of the bow shock wave (less pressure / temperature at the nose), also implies that the boundary layer flow over the skin is much faster - which itself implies an increased frictional (viscous/ shearing) drag and associated heat - which in hypersonics is the real killer here.

One problem with the SKYLON, as you and I touched at the Queer Geer some time ago, is that the elegant supersonic aerodynamic design of the SKYLON suggests little concern for heat transfer problems on the skin, and moreover, it suggests an all metal skin, because it incorporates a straight razor-thin wing / engine pod pylon, and the style of the vertical stabilizer also implies all-metal construction.

The long geometry of the SKYLON also exacerbates the problem of pitch and yaw stability in flight.  Let me explain, the way I view it, with the engine pod pylons serving as straight-edge wings, this design is a "relative" of the 1950s-60s era super-high-efficiency straight-wing supersonic designs (e.g. F-104 Starfighter, X-15 rocket plane, Douglas X-3 Stiletto), and so this design suffers from pitch-yaw stability problems at lower speeds by default (elongated needle shapes with straight wings all share that problem). Maintaining stability with a very heavy aft engine might truly exacerbate the inherent low-speed stability problems, to the point you make a very heavy aircraft, just to not tumble out of the sky.

Douglas X-3 Stiletto: 1950s U.S. Experimental Jet Aircraft (http://www.youtube.com/watch?v=Q0lmt-bhm_k#)



If the pods can't be placed toward the rear, then I'd suggest they must be rectangular in geometry, incorporate a ramp aerospike (directing plumes up and down), and perhaps be a variation of the  "wing rooted design" where the whole engine pod is part of a Straight or Delta wing. Looking more like the engine setup used in the Concorde, but with rectangular aerospikes.

Honestly, I'd abandon the straight wing design.  You might find that solves a lot of the problems with stability and weight related to stability not to mention heat transfer problems - naturally at the expense of added wing weight, but the lesser of two evils.  I do fear however that the Stiletto-style fuselage may be impractical in the end due to heating concerns unless you can extend the cooling from the engines to the fuselage. Perhaps go back to a wave rider configuration like the National Aerospace Plane (NASP), but using a variant of SABRE?

https://en.wikipedia.org/wiki/Rockwell_X-30 (https://en.wikipedia.org/wiki/Rockwell_X-30)

Early 1980s concept for the Rockwell X-30 NASP
The conventional supersonic design requires extremely high-heat resistant metals (which we don't have)

Later Waverider version of Rockwell X-30 NASP
Design has little or no wings, and fuselage acts as engine inlet diffuser, engine outlet nozzle (aerospike), as well as lifting surface by riding on the "shock layer" (highly compressed layer of decomposed air just behind the shockwave's "shock front" (a/k/a Bow Shock)


From https://en.wikipedia.org/wiki/HOTOL (https://en.wikipedia.org/wiki/HOTOL)

QuoteDuring development, it was found that the comparatively heavy rear-mounted engine moved the center of mass of the vehicle rearwards. This meant that the vehicle had to be designed to push the center of drag as far rearward as possible to ensure stability during the entire flight regime. Redesign of the vehicle to do this required a large mass of hydraulic systems, which cost a significant proportion of the payload, and made the economics unclear.[5] In particular, some of the analysis seemed to indicate that similar technology applied to a pure rocket approach would give approximately the same performance at less cost.

The last sentence is critical.  Seems to suggest that vertical ascent would be better using an air-breathing rocket configuration ;D

Seriously anything worthwhile is very difficult.  All of these approaches are feasible, but require larger than acceptable compromises. I think the most feasible part of SKYLON is actually the SABRE engine, to be honest.

I'd pursue either

1) An air-breathing rocket glider similar the X-33 but in a shape closer to the Space Shuttle (read below) with a centrally aft-located aerospike

OR

2) An air breathing wave-rider airplane like the late X-30 NASP,

AND then for either system above develop a modular Inconel mesh re-inforced silica glass fibre brick skin system.  Basically a cross between the X-33 exchangeable metal plates/mesh skin, and the Space Shuttle silica fibre bricks. That skin will be light enough and heat resistant enough to give you a bluntish design that will easily resist re-entry temperatures and still give you large enough control surfaces like the Space Shuttle.

OR

3) If and only if you can solve the skin heating problem, attempt a Delta wing idealised supersonic design, like the early version of the X-30 NASP, but abandon the straight-wing approach, and use rectangular air breathing rockets with rectangular aerospikes incorporated into the Delta wing. This would be the closest to SKYLON. But the materials and skin cooling technology are a question mark to me.

I am going to follow this. At last my recent physics course is coming in handy! I am interested through my dad, who was a pilot, and used to fire up our imagination with planes, and stars and hypothetical trips into space. I have a book of interest but will have to dig it out from the space warp in which it has taken up residence, swot up a little, and join in the conversation. Thank you, J Wilhelm - I toff my Tim Tam to you!

Quote from: J. Wilhelm on October 10, 2015, 06:31:48 AM
(snip)
The long geometry of the SKYLON also exacerbates the problem of pitch and yaw stability in flight.  Let me explain, the way I view it, with the engine pod pylons serving as straight-edge wings, this design is a "relative" of the 1950s-60s era super-high-efficiency straight-wing supersonic designs (e.g. F-104 Starfighter, X-15 rocket plane, Douglas X-3 Stiletto), and so this design suffers from pitch-yaw stability problems at lower speeds by default (elongated needle shapes with straight wings all share that problem). Maintaining stability with a very heavy aft engine might truly exacerbate the inherent low-speed stability problems, to the point you make a very heavy aircraft, just to not tumble out of the sky.

Douglas X-3 Stiletto Supersonic Reasearch Airplane, 1952
https://en.wikipedia.org/wiki/Douglas_X-3_Stiletto (https://en.wikipedia.org/wiki/Douglas_X-3_Stiletto)

Douglas X-3 Stiletto: 1950s U.S. Experimental Jet Aircraft (http://www.youtube.com/watch?v=Q0lmt-bhm_k#)

Lockheed F-104 Starfighter, Mach 2 interceptor jet, 1956
https://en.wikipedia.org/wiki/Lockheed_F-104_Starfighter (https://en.wikipedia.org/wiki/Lockheed_F-104_Starfighter)

(https://upload.wikimedia.org/wikipedia/commons/thumb/d/db/Lockheed_F-104A-10-LO_060928-F-1234S-011.jpg/1024px-Lockheed_F-104A-10-LO_060928-F-1234S-011.jpg)

(snip)

Of course, one difference between Skylon and those aircraft is that Skylon will have a very simple flight profile (in atmosphere); take off, arc up to orbit, de-orbit and then arc back to landing; no sudden or energetic manovers as the above aircraft would have needed to make. And of course Skylon is 'fly-by-wire' without even a human pilot - allowing even an inherently unstable shape to stay in the air (isn't this the case for the {piloted} Typhoon Eurofighter?)

Quote from: J. Wilhelm on October 10, 2015, 06:31:48 AM
(snip)
One problem with the SKYLON, as you and I touched at the Queer Geer some time ago, is that the elegant supersonic aerodynamic design of the SKYLON suggests little concern for heat transfer problems on the skin, and moreover, it suggests an all metal skin, because it incorporates a straight razor-thin wing / engine pod pylon, and the style of the vertical stabilizer also implies all-metal construction.
(snip)

Putting aside the heating during ascent issue, are you thinking of re-entry here? The designers seem to believe this isn't an issue actually due to the shape. Compared to the shuttle, on re-entry Skylon would be a lot less dense (lots of empty space in its fuel tanks) and so should hit a much lower terminal velocity and hence rate of heating. They think this can be managed with a skin coating (and possibly some active cooling via water on leading edges) without resorting to those troublesome tiles. They did have a clever material invented by a French company in mind (there was a clip of it being heated to some ridiculously high temperature to no effect), but there is the slight complication they have gone into receivership.

Yours,
Miranda.

P.S. on a not unrelated note, a nice video showing how the Sierra Nevada Corp hope their Dream Chaser space plane will operate http://www.space.com/30782-dream-chaser-space-plane-2016-tests.html (http://www.space.com/30782-dream-chaser-space-plane-2016-tests.html).

Quote from: Miranda.T on October 10, 2015, 04:59:26 PM

Of course, one difference between Skylon and those aircraft is that Skylon will have a very simple flight profile (in atmosphere); take off, arc up to orbit, de-orbit and then arc back to landing; no sudden or energetic manovers as the above aircraft would have needed to make. And of course Skylon is 'fly-by-wire' without even a human pilot - allowing even an inherently unstable shape to stay in the air (isn't this the case for the {piloted} Typhoon Eurofighter?)

Snip

Putting aside the heating during ascent issue, are you thinking of re-entry here? The designers seem to believe this isn't an issue actually due to the shape. Compared to the shuttle, on re-entry Skylon would be a lot less dense (lots of empty space in its fuel tanks) and so should hit a much lower terminal velocity and hence rate of heating. They think this can be managed with a skin coating (and possibly some active cooling via water on leading edges) without resorting to those troublesome tiles. They did have a clever material invented by a French company in mind (there was a clip of it being heated to some ridiculously high temperature to no effect), but there is the slight complication they have gone into receivership.

Yours,
Miranda.

P.S. on a not unrelated note, a nice video showing how the Sierra Nevada Corp hope their Dream Chaser space plane will operate http://www.space.com/30782-dream-chaser-space-plane-2016-tests.html (http://www.space.com/30782-dream-chaser-space-plane-2016-tests.html).

Regarding stability I'm afraid it's not that easy, dear Miranda. Stability in this case refers  to the natural resistance of a craft to yaw, pitch and roll in the sense of not tumbling at the slightest atmospheric perturbance. The vehicles I mentioned are stable alright, but they are definitely much less stable as they slow down to subsonic speeds to approach the ground.

After re-entry, landing approach is the 2nd deadliest phase of the mission, and a common problem for high speed vehicles that have a small wing area,  such as straight wing supersonic designs and no wing hypersonic designs such as lifting bodies.  This is a major headache, actually. The Delta wing was invented to combine swept wing theory and Supersonic airfoil sections with a greater area for lift and stability.  It resolved the problem of stability at low speeds.

~ ~ ~

The thermal issue is not just for re-entry, but horizontal ascent (and descent) as well.  Unless I'm misreading the ascent / descent flight path (what exactly is that arc?), generically, a space plane must travel a much greater distance within the atmosphere before reaching the 17500 mph speed necessary for low-orbit insertion. Maybe the friction effects during ascent are limited compared to reentry but then you have the issue of flight time duration.

The X-33, and Space Shuttle don't have to suffer from high hypersonic effects for as long as the X-30, HOTOL, or SKYLON would; their only hurdle is to slow down in re-entry, and ascent is largely a supersonic affair.  The rocket gliders' trajectory is steep, and thus much shorter,  and the maximum speed is at an altitude where the atmosphere is very rarefied. The space airplane will endure heat for longer periods of time.

The only thing I can think of is a relatively slow subsonic or supersonic ascent to high altitude and then a quick jump upwards. But that doesn't explain reentry. EDIT: HOLY COATINGS, BATMAN! Upon reading more on the SKYLON, I was surprised to find that they plan to use a ceramic coating. Actually this is a relief, because it's an admission that there are in fact serious thermal issues being dealt with, including chemistry (read below).

~ ~ ~

On shape: Actually the slender shape doesn't help in a re-entry setting or high speed climb cruise even.  It exacerbates the problem. Greatly. Again, long skinny shapes are low-drag affairs,  but the speed of the air next to the skin (boundary layer) is higher, so friction becomes a problem.  Supersonic aircraft don't need to worry about that. But for hypersonic aircraft this is the biggest challenge. It seems the SKYLON design with zero edge blunting just plows through these difficulties. We haven't seen that in actual production vehicles... well, ever.

~ ~ ~

On terminal speed: Regardless of the mass of the vehicle,  re-entry still involves slowing down from orbital speed to - as you say- some terminal speed but high in the atmosphere. But the density of the atmosphere is very low, so either way, no matter your orientation, you will take some time to slow down,  all the while still reaching very high Mach numbers and associated plasma related ablation and chemical reactions due to air decomposition in the shock layer's extreme temperatures downstream from the bow-shock.

Metals, as a general rule and assuming a Mach number range anywhere between 5 and 15 (20-25 for lunar/interplanetary capsules) , will melt, burn (oxidize), and chemically react (radical "adsorption" which is an exothermic reaction - you get more heat),  and even vaporize all at the small time!

Now SKYLON claims a maximum operating Mach number of 27 with the SABRE engines (is that on ascent?). That's higher than the Apollo capsule (M = 24.5 - sounds very high to me). So these skin issues are serious and using metals like in the X-33 is a tremendous complication.  So ceramic it is for the SKYLON.

On descent, SKYLON must slow down very fast with active cooling and a non-chemically reacting skin if they plan to use the fuselage more than a few times. I imagine the SKYLON would reach terminal velocity without any need for power as the re-entry challenge is to dissipate energy, so it can't be that far away from the Space Shuttle or X-33, except that their design doesn't involve a "burning belly"  :D angle of attack. Instead, the design as shown,  suggests the axis of the aircraft is always aligned to the free stream. Pure hypersonic controlled flight at every location along the flight path.

NOW HERE'S THE CLAIM: with a "low ballistic coefficient" (large size/low mass), the SKYLON slows down sooner, without Mach number figures, they claim a reduction to HALF the "maximum temperature in the Space Shuttle of 1,260 °C (2,300 °F).."

Note that in the Space Shuttle, the black High Temperature (HRSI) and white Low Temperature (LRSI) Reusable Insulation tiles, handle operating temperatures of up to 1260 °C (2300 °F), and 1200 °F (649 °C), respectively.  

The only difference between the two tiles, besides size is a cover which gives the black color (borosilicate glass) and white color (aluminium oxide). The black tiles dissipate heat from hypersonic effects much faster by design (this is a thermal effect of the black color itself). The white ones also protect from hypersonic effects but double function by retaining a bit of body heat and reflecting solar radiation by design, to manage heat while in orbit (Actually this is true.  White is like a two-way "closed-door" barrier to heat reflecting any incoming or outgoing radiation. Black on the other hand is like an open door for electromagnetic radiation emitting and absorbing infrared and visible light more efficiently than any other color).


The  nose and wing leading edges of the Space Shuttle are made of a "disposable" material Reinforced Carbon Carbon (RCC), designed to wear out much sooner (ablate), so we really can't compare that to the coating on SKYLON.



What exactly is the re-entry and descent profile for the SKYLON?  You got me thinking  now. What is their "secret sauce?"  :D  There is more than one way to skin a cat, but right now, I'm not knowledgeable on the particular mission design for the SKYLON.

I don't know about the French fellas' special material. To be honest, what I know dates to the turn of the Millennium, as that is when I was active, scholarly speaking. And we know that the French ceramic material will handle about the same temperature as the white LRSI tiles in the Space Shuttle. I haven't seen details on method of installation either. No details. A continuous coating in ceramic seems implausible to me, on account of possible thermal stresses and difficulty in manufacture. You need to allow for thermal expansion and compression of the skin. and structure of the body.

Why I rant against metals: From what I know, metals tend not to do well under such conditions, and the Inconel panels of the X-33, the highest temperature metal skin ever proposed, were designed for 50 cycles of life  about one half the lifespan of the Space Shuttle's silica tiles.


The metal panels in the X-33 slowly turn into "potato crisps"  by warping and scorching before being replaced. The warping issue actually produced points of heat concentration at the posts wher the panels are bolted to a composite lattice, and thus gave many headaches to designers according to the engineers I talked to during a presentation by NASA at the 1998 AIAA Meeting and Exhibit in Reno,  Nevada, (in which I presented my undergraduate research as part of a student contest) . That discussion left an impression in my mind.

In contrast, the silica fiber and ceramic bricks are chemically inert, avoiding the chemical reactions (and heat) from radical adsorption. In the U. S.we went to an extreme amount of effort in the 70s to develop the silica bricks, just  to be able to have a reusable rigid non warping skin for bigger wings and control surfaces, which would afford stability at lower speeds and in landing.

On the X-33, engineers compromised on rigidity and lifespan, thinking the disposable metal panels would be cheaper to make and much easier to replace (the real cost of that silica brick skin and a big reason for the Shuttle being over budget was maintenance of the bricks, actually).

Quote from: J. Wilhelm on October 11, 2015, 01:32:10 AM
(snip)

Regarding stability I'm afraid it's not that easy, dear Miranda. Stability in this case refers  to the natural resistance of a craft to yaw, pitch and roll in the sense of not tumbling at the slightest atmospheric perturbance. The vehicles I mentioned are stable alright, but they are definitely much less stable as they slow down to subsonic speeds to approach the ground.

(snip)

On shape: Actually the slender shape doesn't help in a reentry setting or high speed climb cruise even.  It exacerbates the problem. Greatly. Again, long skinny shapes are drag affairs,  but the speed of the air next to the skin (boundary layer) is higher, so friction becomes a problem.  Supersonic aircraft don't need to worry about that. But for hypersonic aircraft this is the biggest challenge. It seems the SKYLON design with zero edge blunting just plows through these difficulties. We haven't seen that in actual production vehicles... well, ever.

(snip)

Metals, as a general rule and assuming a Mach number range anywhere between 5 and 15 (20-25 for lunar/interplanetary capsules) , will melt, burn (oxidize), and chemically react (radical "adsorption" which is an exothermic reaction - you get more heat),  and even vaporize all at the small time!

Now SKYLON claims a maximum operating Mach number of 27 with the SABRE engines (is that on ascent?). That's higher than the Apollo capsule (M = 24.5 - sounds very high to me). So these skin issues are serious and using metals like in the X-33 is a tremendous complication.  So ceramic it is for the SKYLON.

(snip)

On descent, SKYLON must slow down very fast with active cooling and a  reacting skin if they plan to use the fuselage more than a few times. I imagine the SKYLON would reach terminal velocity without any need for power as the reentry challenge is to dissipate energy, so it can't be that far away from the Space Shuttle or X-33, except that their design doesn't involve a "burning belly"  :D angle of attack. Instead, the design as shown,  suggests the axis of the aircraft is always aligned to the free stream. Pure hypersonic controlled flight at every location along the flight path.

(snip)

REL seem to be aware of the heating during ascent issue, and think that this will not last long enough to be a problem; another reason why they point out Skylon could not be used as a hypersonic airliner (at last one that stayed in the atmosphere). As far as I know, Skylon is supposed to reenter in a shuttlecock manner (i.e. belly first).

Metals are indeed bad news in this context - witness the Columbia disaster. In terms of the choice of material, I guess it's a playoff between peak temperature and time of heating. If you have a lower terminal velocity, you need to withstand a lower peak temperature but do so for a longer time; you do indeed need to get rid of that gravitational potential energy somewhere.

Yours,
Miranda.

greetings all. Mr. Wilhelm i doubt you'll recall but we briefly discussed such topics a few times, i found the conversations enjoyable. i am currently studying engineering and intend to study aerospace engineering at university, i hope to be able to engage here despite my admittedly poor knowledge i have a passion for the subject.
sincerely
CloudWolf (aka Josh/Claudia)

Quote from: CloudWolf on October 11, 2015, 03:29:02 PM
greetings all. Mr. Wilhelm i doubt you'll recall but we briefly discussed such topics a few times, i found the conversations enjoyable. i am currently studying engineering and intend to study aerospace engineering at university, i hope to be able to engage here despite my admittedly poor knowledge i have a passion for the subject.
sincerely
CloudWolf (aka Josh/Claudia)

Ah! Cloudwolf, welcome aboard. Claudia! Lovely name. (And how coincidentally appropriate for a Last Exile reference!)  I'm sure you'll enjoy the thread, but I'm afraid the conversation got very technical very fast in a very haphazard way. Welcome and come drink from the Firehose of Knowledge!  ;D

Thankfully I have not needed to resort to ant maths - yet). I'm sure you're trying to get all of this stuff right now - if you are anything like me at the time. 

Some sage advice on the college programme, if I may:

It Strikes me I'm cluttering this thread with my obsession for space-planes* (notice I don't say unhealthy obsession, as I have a healthily wide and diverse range of obsessions  ::)). Anyway, that is not the reason the good Admiral started this thread, so I thought I should throw in an alternative line of discussion, which is: Steampunk human powered flight.

Now, there were many varied and fantastical Victorian designs for such a thing (plenty of images here https://www.google.co.uk/search?q=victorian+human+powered+flying+machine&hl=en-GB&gbv=2&prmd=ivns&tbm=isch&tbo=u&source=univ&sa=X&ved=0CBQQsARqFQoTCM3uscqGu8gCFYUXPgodfA8Nsw (https://www.google.co.uk/search?q=victorian+human+powered+flying+machine&hl=en-GB&gbv=2&prmd=ivns&tbm=isch&tbo=u&source=univ&sa=X&ved=0CBQQsARqFQoTCM3uscqGu8gCFYUXPgodfA8Nsw), but it took until the latter part of the 20th century for the ambition to be realised (https://en.wikipedia.org/wiki/Human-powered_aircraft (https://en.wikipedia.org/wiki/Human-powered_aircraft)). But of course, these aircraft took full advantage of modern lightweight materials (aluminium, synthetic skins for the frame, more recently carbon fibre). The question is, with the right design could this possibly have been achieved using materials available in the Victorian era?

I'll get the ball rolling; my (admittedly a bit unhinged) thought is to use nature's solution, and build the framework using bones from birds - already evolved to be strong and light. Of course, two issues present themselves. Size - given that a roc might be a bit difficult to find, a latticework structure would need to be built up from smaller bones, although 'smaller' is a relative term - we'd be talking say albatross. Which then brings me to the second issue - to collect enough bones, how many albatross' would you need to hunt? (Hear the rime of the ancient mariner...)

Anyway, if anyone else has a better idea than this (probably not difficult), please feel free to suggest away!

Yours,
Miranda.

*I think this particular obsession comes from the frustration that we seem to be going backwards in terms of humanity's ambitions for space. Orion/SLS, Dragon/Falcon etc. just feel like a throwback to the 60s and 70s, notwithstanding claims for possible reusability. The shuttle always looked to me as the right way to go, but its design was too compromised by too many 'intersted parties' making demands on it and budget limits. So, I'm really hopeful that Skylon, Dream Chaser** et.al. will get things back on track.

** Although this is, ironically for my argument, based on work from the 1950s & 60s (the Dyna-Soar project).

Aaah! You know, dear Miranda?  The problem is that I've always been an aeronaut.


If you have an obsession on space planes then I'm barking-mad and screaming from a cell deep inside the metal sanatorium. After all, I dedicated 9 years of my life and spent well over $30000 of my money to specifically answer the question "how does the Space Shuttle work?"

Now tell me again about the degree of your obsession?  :D  ;D  You're bragging about being evil while talking to the devil himself! Ha, ha, ha!

Quote from: Miranda.T on October 11, 2015, 01:38:23 PM
REL seem to be aware of the heating during ascent issue, and think that this will not last long enough to be a problem; another reason why they point out Skylon could not be used as a hypersonic airliner (at last one that stayed in the atmosphere). As far as I know, Skylon is supposed to reenter in a shuttlecock manner (i.e. belly first).

Aaargh! SKYLON seems to defy every single expectation! I guess they're just pushing the numbers as far as they can. I'm not seeing the thermal shuttlecock re-entry on it, but probably because the skin - quite frankly from my POV - is simply not developed yet beyond a concept.  All they have is the ceramic. I do buy the part of the corrugated shell, though, but read below.....

I need to see re-enforcements for leading edges, separate segments with different thermal resistance coefficients, cooling systems, etc, before I see this neat diamond-wing supersonic design do a "bellyflop" re-entry.  The technical jargon is to say that the thermal characteristics of the windward surface ("belly") are different from the thermal characteristics of the Leeward side. So you expect some variance in thermal protection like the space shuttle has...

X-33 Hypersonic Aerodynamics (1999)
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20040087108.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20040087108.pdf)

Discussion on transition to turbulence for the X-33 (1998)
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980037670.pdf (http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19980037670.pdf)

In 1998 NASA and Lockheed made like - I don't know- more than 10 presentations on the X-33 in Reno. Pfft! probably way more, they had an entire section of the conference just for the X-33. Students were having their own competition among the professionals.

This was the paper I was presenting on my research with Dr. Goldstein in the same conference. I had previously won the regional segment of the contest (two year cycle - talk about an ego boost for a 4th year student)  ;D

http://arc.aiaa.org/doi/abs/10.2514/6.1998-7 (http://arc.aiaa.org/doi/abs/10.2514/6.1998-7)

*Sigh* The X-33 was like that though... it broke every single rule in the text-book, and the engineers made you believe it would fly. But the data was really out, available in the open and talked about in detail in the AIAA conferences. Long before the experiments were over we were already talking about the complications of the skin.

Giant autoclave-cured carbon fibre fuel tanks (which kept de-laminating), copper aerospike (yeah, I know let's not go there), metal skin (potato crisps / my pizza-baking sheet in the oven).  It's like mental torture. The only thing proven thing on the concept was the lifting body Dyna-soar pedigree it had. But at least there was the talk about it...

Quote from: Miranda.T on October 11, 2015, 01:38:23 PM
*snip*
Metals are indeed bad news in this context - witness the Columbia disaster. In terms of the choice of material, I guess it's a playoff between peak temperature and time of heating. If you have a lower terminal velocity, you need to withstand a lower peak temperature but do so for a longer time; you do indeed need to get rid of that gravitational potential energy somewhere.

I actually found this AIAA paper written for the 18 th AIAA International Space Planes and Hypersonic Systems and Technologies Conference in Tours, France, 26 September 2012...

AIAA Conference Paper
https://www.aiaa.org/WorkArea/DownloadAsset.aspx?id=14414 (https://www.aiaa.org/WorkArea/DownloadAsset.aspx?id=14414)

SKYLON Website:
http://www.reactionengines.co.uk/space_skylon_tech.html (http://www.reactionengines.co.uk/space_skylon_tech.html)

Not that I'm sold on it though...  The SKYLON is like a Pandora's box. It's very radical. Everywhere I look I find something surprising an unxpected. Just when I'm getting exited about the French thermal coating I read this...

QuoteSkin (kg/m^2) 1.537 (0.5mm SiC/glass ceramic, corrugated 2x20mm)

The aeroshell is being described as a thin corrugated ceramic skin no more than 1/2 mm in thickness (Page 34 of AIAA paper)  if I read that correctly.  :o   I imagine the skin is being held up by posts on to a lattice, similar to the X-33, and weighing about 8.7% of the total dry weight of 42.3 metric tonnes. The weight of the skin is about the same as the weight of the composite internal structure (space frame), and both are very light indeed.

I'm happy that it's a ceramic, for reasons already explained, and the corrugated part seems very similar to the thin-shell strengthening method use for the Space Shuttle's external tank. The floating lattice ius something that the X-33 had.

But that thickness for a ceramic shell is odd and it's a bit of a let down. Naturally the fear is that assuming you can sustain vibration, and thermal expansion, and everything else, that it will be strong enough to not be breached by impact. More importantly, for consequences look at the Space Shuttle Columbia tragedy.  

My fear is that a super thin brittle aero-shell is an inherent risk, if impacted by anything at those speeds (I guess an unmanned vehicle is a good idea). Though admittedly the SKYLON is highly unlikely to encounter debris flying high during ascent, the same way a chunk of foam from the External Tank detached an accelerated to an impact of 1 metric tonne onto the leading edge of the Columbia (there was no metal involved actually).

The fear really is more at low speeds and low altitudes where it is far more likely to get hit by something dense.  Bird strikes and a Concorde-style tarmac-debris strike can't be ruled out for a horizontal flight takeoff! This is now an aeroplane, after all.  It needs to fly low to the ground.

https://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaster (https://en.wikipedia.org/wiki/Space_Shuttle_Columbia_disaster)

https://en.wikipedia.org/wiki/Air_France_Flight_4590 (https://en.wikipedia.org/wiki/Air_France_Flight_4590)

Quote from: Miranda.T on October 11, 2015, 07:12:00 PM
It Strikes me I'm cluttering this thread with my obsession for space-planes* (notice I don't say unhealthy obsession, as I have a healthily wide and diverse range of obsessions  ::)). Anyway, that is not the reason the good Admiral started this thread, so I thought I should throw in an alternative line of discussion, which is: Steampunk human powered flight.

Ah! Perfect.  Then I'll post this here for practical inspiration, while I go run some errands, this Sunday.  I need to shift my brain from AIAA conferences to Leonardo da Vinci, and as it turns out college life will cover both subjects quite nicely

I had posted about the Igor Sikorsky Human Powered Helicopter Competition in another thread.  This is a Da-Vinci-esque competition that has been running for decades and a kind of Holy Grail for college students

AeroVelo Wins the 33-Year Old AHS Igor I. Sikorsky Human Powered Helicopter Competition (http://www.youtube.com/watch?v=99p_wh6p4OY#)

Human-Powered Helicopter: Straight Up Difficult (http://www.youtube.com/watch?v=emK-qIbuJ-k#):

Quote from: Miranda.T on October 11, 2015, 07:12:00 PM
It Strikes me I'm cluttering this thread with my obsession for space-planes* (notice I don't say unhealthy obsession, as I have a healthily wide and diverse range of obsessions  ::)). Anyway, that is not the reason the good Admiral started this thread, so I thought I should throw in an alternative line of discussion, which is: Steampunk human powered flight.

Now, there were many varied and fantastical Victorian designs for such a thing (plenty of images here https://www.google.co.uk/search?q=victorian+human+powered+flying+machine&hl=en-GB&gbv=2&prmd=ivns&tbm=isch&tbo=u&source=univ&sa=X&ved=0CBQQsARqFQoTCM3uscqGu8gCFYUXPgodfA8Nsw (https://www.google.co.uk/search?q=victorian+human+powered+flying+machine&hl=en-GB&gbv=2&prmd=ivns&tbm=isch&tbo=u&source=univ&sa=X&ved=0CBQQsARqFQoTCM3uscqGu8gCFYUXPgodfA8Nsw), but it took until the latter part of the 20th century for the ambition to be realised (https://en.wikipedia.org/wiki/Human-powered_aircraft (https://en.wikipedia.org/wiki/Human-powered_aircraft)). But of course, these aircraft took full advantage of modern lightweight materials (aluminium, synthetic skins for the frame, more recently carbon fibre). The question is, with the right design could this possibly have been achieved using materials available in the Victorian era?

I'll get the ball rolling; my (admittedly a bit unhinged) thought is to use nature's solution, and build the framework using bones from birds - already evolved to be strong and light. Of course, two issues present themselves. Size - given that a roc might be a bit difficult to find, a latticework structure would need to be built up from smaller bones, although 'smaller' is a relative term - we'd be talking say albatross. Which then brings me to the second issue - to collect enough bones, how many albatross' would you need to hunt? (Hear the rime of the ancient mariner...)

Anyway, if anyone else has a better idea than this (probably not difficult), please feel free to suggest away!

Yours,
Miranda.

*I think this particular obsession comes from the frustration that we seem to be going backwards in terms of humanity's ambitions for space. Orion/SLS, Dragon/Falcon etc. just feel like a throwback to the 60s and 70s, notwithstanding claims for possible reusability. The shuttle always looked to me as the right way to go, but its design was too compromised by too many 'intersted parties' making demands on it and budget limits. So, I'm really hopeful that Skylon, Dream Chaser** et.al. will get things back on track.

** Although this is, ironically for my argument, based on work from the 1950s & 60s (the Dyna-Soar project).

I would think that gliders (wind powered, so still not human-powered) would not be that much of an issue... Surely a team of horses could get the thing aloft, proportions, design, and materials all being appropriate, of course.

But Miranda proposes human-powered flight... First, trying to emulate birds flapping their wings is right out, as my admittedly limited understanding of such things allow. A human is just never going to generate the power to flap wings that, to be sufficient to carry their weight aloft has to be stupidly long in the first place, not to mention that flapping is only part of the trick anyway (I'm told some folks got together to do the math to make Pegasus work; I don't remember the exact figures, but you wouldn't be able to get anywhere near the horse because of the wingspan). I vaguely recall reading that humans, which are mammals to begin with, need to stop trying to emulate birds, but instead emulate bats (see DaVinci's glider; also, the wing shape, not the flapping).

So okay; no flapping = fixed wing design, + bat-like wing design. The membrane should be no problem; I would think someone could have figured out how to do this, with a certain type/x number of layers/treatment, whatever, in silk. I don't see a thin-enough leather working, just because of the weight of it. Now, for the framework...

...Miranda has suggested Frankensteining together x number of bird bones since these are already the correct structure. We can't follow bat bones here; they're not hollow, and are relatively thin and fragile. But you know what else is hollow and fairly strong? Bamboo. Why not try that? If I remember correctly, bird bones, while hollow, still have a sort of matrix of supporting bone within the larger cavity. If that's the case, and the bamboo required it to support this project, could the hollow bits of the bamboo have some sort of supporting matrix, itself made of bamboo or bird bone or something else? If I do not remember correctly, the previous two sentences are moot.

I know 90% of what I just proposed is impractical/unfeasible/impossible, but I know others on this thread could tell me why it's wrong and/or how it could work.

Still, from a completely practical standpoint, I would think gliders would be the way to go, but again, it's not technically human-powered, then.

On your mark:  Read, set, MATH!

What do you think of this set-up?

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Fwww.dcgeorge.com%2Fimages%2FProjectFalcon%2FFalcon12aOverview.jpg&hash=751549efe64bd7afbf9c5610b33ea108a7443f87)

http://www.dcgeorge.com/ProjectFalcon_f.html (http://www.dcgeorge.com/ProjectFalcon_f.html)

Or this?

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2F3.bp.blogspot.com%2F_aT16HxfS63I%2FSyR4Cy_p9YI%2FAAAAAAAAA5A%2FXc54YnsMtTs%2Fs400%2FDSC01807.JPG&hash=1a3785ce4a80cb3de8ff0d84be0c7e407713cbd7)

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2F1.bp.blogspot.com%2F_aT16HxfS63I%2FSyR4CcqN9pI%2FAAAAAAAAA44%2FLH4rDbscS44%2Fs400%2FDSC01819.JPG&hash=6bec3a8e9a62b12e259fb599709c205465beff26)

http://voyagesextraordinaires.blogspot.com/2010/03/fortress-explorations.html (http://voyagesextraordinaires.blogspot.com/2010/03/fortress-explorations.html)

Assuming this were a glider (or, what the heck, even if it's not), what is wrong/right with this design (bottom left only)?

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Flh3.ggpht.com%2F_hVOW2U7K4-M%2FSRDg5PbSDEI%2FAAAAAAAAj5Q%2FWe8Ngar_62Q%2Fs640%2Fe56u6trjutyjghk%252Chj%252C.jpg&hash=620a96e232377337424019e6d3e06b76c709720a)

http://www.darkroastedblend.com/2008/11/those-magnificent-men-and-their-flying.html (http://www.darkroastedblend.com/2008/11/those-magnificent-men-and-their-flying.html)

Quote from: GCCC on October 11, 2015, 09:43:35 PM
Assuming this were a glider (or, what the heck, even if it's not), what is wrong/right with this design (bottom left only)?

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Flh3.ggpht.com%2F_hVOW2U7K4-M%2FSRDg5PbSDEI%2FAAAAAAAAj5Q%2FWe8Ngar_62Q%2Fs640%2Fe56u6trjutyjghk%252Chj%252C.jpg&hash=620a96e232377337424019e6d3e06b76c709720a)

http://www.darkroastedblend.com/2008/11/those-magnificent-men-and-their-flying.html (http://www.darkroastedblend.com/2008/11/those-magnificent-men-and-their-flying.html)

Isn't that one of Otto Lilienthal's gliders?  If so I believe it did fly!

https://en.m.wikipedia.org/wiki/Otto_Lilienthal (https://en.m.wikipedia.org/wiki/Otto_Lilienthal)

Quote from: GCCC on October 11, 2015, 09:27:17 PM
What do you think of this set-up?

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Fwww.dcgeorge.com%2Fimages%2FProjectFalcon%2FFalcon12aOverview.jpg&hash=751549efe64bd7afbf9c5610b33ea108a7443f87)

http://www.dcgeorge.com/ProjectFalcon_f.html (http://www.dcgeorge.com/ProjectFalcon_f.html)

Normally I'd go crazy critical on a design like this one.  But given how relatively easy it is to actually generate lift if you understand the forces needed and in the presence of sufficient power, there is a chance this can happen.

The thing is that until very recently, engineers and scientists did not understand how some animals could generate enough power to move as swiftly as they could

There is an energy recycling method that evolution has incorporated into the motor control of vertebrates.  In general terms for any kind of flapping motion, whether you are generating lift by flapping wings or flapping fins - which admittedly are two very different methods of propulsion,  there is always a vortex "down wash" from which you can recuperate energy by "slapping " the vortex in the right way at the right time.

The fluid mechanics of flapping involves a type of non dimensional frequency called the Strouhal Number, St, used traditionally to characterize fluid mechanics phenomena such as Karman "vortex streets"  The Strouhal number has been linked by experiment to what scientists have found to be a natural frequency of flapping for each type of animal,  whether it flies or swims,  with the experiments  happening in the 1990s at universities like MIT and Caltech.

https://en.wikipedia.org/wiki/Strouhal_number (https://en.wikipedia.org/wiki/Strouhal_number)


The Strouhal number depends on the forward speed motion of the animal, U, the flapping frequency, f in Hertz,  and some characteristic scale, L, of the animal, all of which is related to the size and motion of the downwash vortex from flapping, and thus is a good predictor of optimum flapping frequency to recover as much energy from the downwash as possible.

A myriad of hummingbird and insect like drones has appeared in recent years, no doubt enabled by this science. Smaller animals (insects,  hummingbirds)  having the highest frequency,  and large animals like  condors having the slowest flapping frequency.   I wonder if this ornithopter enthusiast is aware of that  theory....


Under certain low speed conditions (which applies to most animal locomotion), air basically behaves like water, so adjusting for viscosity you may be able to reproduce the fluid dynamics of water in air, and viceversa (that is why there is such a thing as "water channels" as opposed to "wind tunnels."

Who in Brassgoggles remembers when we were posting about the robotic penguins built by a company called Festo?

Quote from: J. Wilhelm on October 11, 2015, 08:32:08 PM
Aaah! You know, dear Miranda?  The problem is that I've always been an aeronaut.
(snip)

Ah. and there is the source of part of my frustration. The promised cheap access to space that the shuttle promised to bring was supposed to give much wider access to scientists and engineers; you could be an aeronaut/astronaut without needing to qualify as 'the best of the best'. for well-known reasons the shuttle didn't do that, and I just don't see the current efforts from NASA or SpaceX really challenging the status quo.

Quote from: J. Wilhelm on October 11, 2015, 08:32:08 PM
(snip)
This was the paper I was presenting on my research with Dr. Goldstein in the same conference. I had previously won the regional segment of the contest (two year cycle - talk about an ego boost for a 4th year student)  ;D
(snip)

Impressive!

Quote from: J. Wilhelm on October 11, 2015, 08:32:08 PM
(snip)
Giant autoclave-cured carbon fibre fuel tanks (which kept de-laminating), copper aerospike (yeah, I know let's not go there), metal skin (potato crisps / my pizza-baking sheet in the oven).  It's like mental torture. The only thing proven thing on the concept was the lifting body Dyna-soar pedigree it had. But at least there was the talk about it...
(snip)

As with the HOTOL project, I was disappointed when that programme was cancelled. Then the shuttle was deemed to be too unsafe to continue to fly. It looked like the idea of a cheap and regular access to space via a fully reusable vehicle had died, but them SpaceshipOne helped re-ignite interest in this (although it of course it is a bit of a cheat - sub-orbital, side-stepping the thorny issue of full re-entry).

Quote from: J. Wilhelm on October 11, 2015, 08:32:08 PM
(snip)
Aaargh! SKYLON seems to defy every single expectation! I guess they're just pushing the numbers as far as they can. (snip)

That is certainly a comment I've seen before in the context of Skylon - if it is to work at all, it wll be right on the edge. By that way, on the cotext of Columbia it was not so much the initial strike I was thinking of but the burn-though of the wing's structure on re-entry; the aluminium framework of course never stood a chance with the protective tiles lost.

Quote from: GCCC on October 11, 2015, 09:25:43 PM
(snip)
...Miranda has suggested Frankensteining together x number of bird bones since these are already the correct structure. We can't follow bat bones here; they're not hollow, and are relatively thin and fragile. But you know what else is hollow and fairly strong? Bamboo. Why not try that? If I remember correctly, bird bones, while hollow, still have a sort of matrix of supporting bone within the larger cavity. If that's the case, and the bamboo required it to support this project, could the hollow bits of the bamboo have some sort of supporting matrix, itself made of bamboo or bird bone or something else? If I do not remember correctly, the previous two sentences are moot.
(snip)

Bamboo - I do like that idea. I was wondering if you could stopper the ends whether you could pressurise the inside channel by forcing compressed air into it to give extra rigidity. I don't know if the structure of bamboo could hold the pressurised air, though.

I have to say I'm thinking a peddle type arrangement and propeller; flapping is vastly too complicated. The propeller itself would have to be extremely lightweight. However, some of the images you posted... Maybe using hydrogen gas-bags to help with lift. The problem is that just slinging a bike with a propeller under a dirigible, the poor pilot would be too subject to the wind blowing then around (although maybe they'd stand a chance with two peddlers...  ::)), so possibly just use small gas-bags to help lift rather than fully provide it; I'm wondering about putting them inside the aerofoil section of the wings - no penalty in terms of wind pressure, and, if pressurised, could help give the wind shape and structure.

Yours,
Miranda.

Indeed it was a great disappointment to see the X-33 canceled as well.  The X-33 incorporated all the most radical techniques available into one project,  then someone at Skunk Works committed the first cardinal sin of prototyping by actually setting the goal of using the testing model as the actual flight test model.  Which is never done,  because the structure is weakened by structural testing.  Also, they were supposed to complete the project in 3 years.  Both practices of which were something I had never heard of before.  I felt the project was doomed from the start. The X-33 was a 1/2 size prototype of Venture Star, the final goal.

Nevertheless the discussion at AIAA gave you the impression that they were serious on the nitty gritty of engineering (see attached papers). All the plans were finalised.  As the photo shows,  they were serious on the testing.  They fabricated the tanks from carbon fibre.  The problem is that one by one the technologies tested started failing.  The tanks started de-laminating in testing.  It had to do with non uniform curing after coming out from the autoclave - one of the largest in the world? The Venture Star would need a specially made autoclave.  And the welded aerospike ramp fell apart in testing,  They switched to aluminium tanks,  but by then the vehicle was so heavy they had to make design changes including an external fuel tank that looked like a pencil.  At that point the project was killed.

The project failed in part because of unrealistic goals set from the start, having less to do with the physics of it and more to do  with engineering procedure.  The technology could have made it, if they had taken the time to properly develop and test the technologies involved.  Not 3 years, but say 10, I'd say. With testing of several prototypes at every step of the way.

~ ~ ~

Flapping is in fact very complicated,  Flapping can be of several types and involves forward motion and tilting of the wing while flapping,  because of both drag and boundary layer separation and also to "recycle" the energy of the downward vortex as I explained.


~ ~ ~

Well,  cylindrical tubes are very strong by default. Filling them may or may not be necessary, depending on what you're doing with them.  For two-force members such as in a lattice, you'll probably not need filling.  To withstand bending moments and torsion as in a standard frame,  those elements could be filled with neoprene foam.

~ ~ ~

Two peddlers are absolutely necessary,  especially if your second peddlers name is Maximilian Meen. This effort could be part of a Great Race.  You know, it's Fate,  and all that jazz.   ::)

http://youtube.com/#/watch?v=7vE3Z5-6ROc (http://youtube.com/watch?v=7vE3Z5-6ROc#)

For those interested in such things, this link is to a PDF detailing the current state-of-play with respect to Skylon's development: http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36826.0;attach=1073534 (http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36826.0;attach=1073534).

Yours,
Miranda.

Quote from: Miranda.T on October 15, 2015, 09:22:42 PM
For those interested in such things, this link is to a PDF detailing the current state-of-play with respect to Skylon's development: http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36826.0;attach=1073534 (http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36826.0;attach=1073534).

Yours,
Miranda.

Dear Miranda:

I finally gave myself the time to read the first paper you posted, the arodynamics asessment by the three NASA workers on the Skylon. Their assessment is pretty grim, worse than I've would have given.

One word of caution: these engineers chose to use a Direct Numerical Simulation (DNS) method (Finite Volume DNS package), but using the Euler Equations. I wouldn't have done that, even back in 1998, when computers were slower...

HOWEVER (and ignoring that their  technical communication skills are questionable), their findings are not, shall we say, encouraging? They really kill the design.

http://www.nas.nasa.gov/assets/pdf/papers/Mehta_Unmeel_Skylon_2015.pdf (http://www.nas.nasa.gov/assets/pdf/papers/Mehta_Unmeel_Skylon_2015.pdf)


Understanding what they wrote, I re-interpret here:



~ ~ ~

In other news, I found these videos all of you might find interesting.

My God man! Look at that hair and those moustaches!  Did graduate students really look like that back in the 1980s? I started college in 1987 and I don't remember being that funky.  ;D

Part 1 NOVA The Light Stuff (human-powered flight) (http://www.youtube.com/watch?v=cZjHcjyLprw#)

Part 2 NOVA The Light Stuff (human-powered flight) (http://www.youtube.com/watch?v=Dhlt1fsnhVE#)

Part 3: NOVA The Light Stuff (human-powered flight) (http://www.youtube.com/watch?v=kdwLB0yoGmE#)


*Edited for scientific terminology correctness.

Out for a pleasant afternoon flight
(https://lh3.googleusercontent.com/EPP_SBBlmO9kplUZbdqT0_sWXwM4KcQS6CXuFUyumFDswcQNqoQuhUWzMnyirYDc_MOtt7Sfugta3IugbppqnT5zEWVTdpkfKJI78z42zEmnQZFTDtnCQcmVk2let1hd7JXu2LkD6u_PZ2-8TerdtureiEniRy4VdQurlhr7n5Wk0C-czqn8FJ0IZGjgMhSGQXR1Cs-GmszSomlv63QstAe5ww5xc5jBo3KH9_AlPOIzByC-0CBPHxxBvg5XSuUS4BEB6-DRJ3dRvXQ6DGc6TLu3cmKat08IJ-EhElx4pegrC__ka2qDZ8mVm73JgZgvWKFJKUbFeGV9yyW3F0KLXkGTuVgPNUx6CuyYTqiYR9jqsmVFU7_pm0kdD3TD3qajKMuNd8MasXLqTKMLGLB7-6rQa1yht1dfDXgHbMpUpVQpqYdYiht6MeiE9I67Zm2m-MuNLnmNNqCGKpy_s_Qn1A3EaFxKFMhVA1MDF4t5JmUtnHGS0or8zVUAVdCPYxaMOHgrzB_3nralPhpWOM2khnJqa-FLmIyXDo2qwA=w320-h480-no)

Dear Admiral Wilhelm,
That's some heavy fluid-dynamics you're cooking with there! That doesn't look too promising. It seems REL are moving towards putting together a full engine for ground-based tests in the next couple of years, so I guess once (if) that is working they can start to quantify these issues more concretely.

Yours,
Miranda.

Quote from: Miranda.T on October 16, 2015, 06:37:18 PM
Dear Admiral Wilhelm,
That's some heavy fluid-dynamics you're cooking with there! That doesn't look too promising. It seems REL are moving towards putting together a full engine for ground-based tests in the next couple of years, so I guess once (if) that is working they can start to quantify these issues more concretely.

Yours,
Miranda.

What I'd like to see is for REL to continue research on the engine and instead of pushing for a payload bearing vehicle, concentrate on an traditional cylindrical rocket equipped with a SABRE air breathing engine for the sole purpose of testing the engine in the Mach 5-20+ range as well as the plume dynamics, and possibly the aerodynamics of an engine pod. That engine could be very important.

The progress of the more developed SABRE engine concept is being held back. By what I see as a hastily designed and secretive space plane airframe concept, which in my opinion requires a heavy conceptual overhaul,  vis a vis engine placement, further practical design of re-entry thermal protection systems and possibly engine nozzle geometry,  to actually become a viable SSTO vehicle.

Trying to do too much at the same time kills projects,  like it happened to the X-33. What is a perfectly viable project,  quickly becomes a white elephant in the eyes of investors, and the project as a whole ends up terminated.

Once the Sabre engine is developed, it will be much easier to sell the Skylon project to investors. A proven technology allows you to concentrate in areas that need developing. Then you can develop a new kind of space plane.

Consider the X-33.  Skunk Works was developing a new airframe (carbon composite), new skin (metal plates), new tanks (carbon fibre), and new engine (aerospike). Only the lifting body design was a derivative of past experience.

Result:  Each technology faced problems during developing. They ran out of time, and the whole design depended on all new technologies working.  When that didn't happen the design changed so much it was no longer an SSTO. The project was cancelled.

Now compare to the Space Shuttle:

Engines <== Saturn V moon rocket technology
Solid Rocket Booster  <== ICBM technology
Airframe technology <== traditional aluminium airframe technology with sparred wings, skin
External Tank corrugated (metallic thin shell pressure vessel) <== More Saturn V technology
~
Thermal Protection System <== All new technology
Hypersonic Lifting Body Design <== All new technology

They only had to concentrate on the aerodynamic design and thermal protection system.  The rest could be handled by industry subcontractors knowledgeable on their respective areas (Thiokol, Martin Marietta, etc.) Subcontractors upon subcontractors joined the team. Rockwell developed the Orbiter.

The "secret sauce" was that the skin allowed airframe designers to make a glider that actually looked like an airplane.  It had a delta wing.  A big one. With a huge vertical stabilizer, which implies slow speed positive control.

Result? A success. Just two new technologies were developed, the rest was sure-footed technology. The Space Shuttle itself was solid as a rock.  Outside of the two tragedies brought about by a defective O-ring, and a foam impact on the leading edge, that Orbiter was actually pretty good. A nightmare to maintain the tiles. And chunky-looking, but  a perfect design. It just worked.


http://www.youtube.com/watch?v=P2itpixEZ6o# (http://www.youtube.com/watch?v=P2itpixEZ6o#)

Note: On ascent, upon orbital insertion, last measured Mach No. is 25 (12:04 min).
http://www.youtube.com/watch?v=PsHljHRM67c# (http://www.youtube.com/watch?v=PsHljHRM67c#)

Quote from: Peter Brassbeard on October 16, 2015, 03:28:57 PM
Out for a pleasant afternoon flight
(https://lh3.googleusercontent.com/EPP_SBBlmO9kplUZbdqT0_sWXwM4KcQS6CXuFUyumFDswcQNqoQuhUWzMnyirYDc_MOtt7Sfugta3IugbppqnT5zEWVTdpkfKJI78z42zEmnQZFTDtnCQcmVk2let1hd7JXu2LkD6u_PZ2-8TerdtureiEniRy4VdQurlhr7n5Wk0C-czqn8FJ0IZGjgMhSGQXR1Cs-GmszSomlv63QstAe5ww5xc5jBo3KH9_AlPOIzByC-0CBPHxxBvg5XSuUS4BEB6-DRJ3dRvXQ6DGc6TLu3cmKat08IJ-EhElx4pegrC__ka2qDZ8mVm73JgZgvWKFJKUbFeGV9yyW3F0KLXkGTuVgPNUx6CuyYTqiYR9jqsmVFU7_pm0kdD3TD3qajKMuNd8MasXLqTKMLGLB7-6rQa1yht1dfDXgHbMpUpVQpqYdYiht6MeiE9I67Zm2m-MuNLnmNNqCGKpy_s_Qn1A3EaFxKFMhVA1MDF4t5JmUtnHGS0or8zVUAVdCPYxaMOHgrzB_3nralPhpWOM2khnJqa-FLmIyXDo2qwA=w320-h480-no)

Welcome aboard, Mr. Brassbeard! I see you have come to us 'a la Montgolfier!  Tried and true technology never dies.

I think one has to see the shuttle as a qualified success.

On the plus side, it took more individuals into space than all other launch systems put together, it allowed the ISS to be built, it provided at platform for unprecedented advances in space science and completed audacious missions such as the Hubble repair. Oh, and it was the most complex transportation system ever built.

On the down side, operating costs were vastly more than promised (which many see as 'shackling' NASA to low Earth orbit by eating up large proportions of its budget), it's launch frequency and flexibility again never matched the promises, and 14 astronauts lost their lives due to it, which I believe is the single largest loss to any particular launch system (I think early Soyuz was 4 fatalities, but nothing since the early days); at the end, wasn't the estimate of catastrophic failure down to something like 1 in 50 flights?

Yours,
Miranda.

Quote from: Miranda.T on October 18, 2015, 10:44:18 AM
I think one has to see the shuttle as a qualified success.

On the plus side, it took more individuals into space than all other launch systems put together, it allowed the ISS to be built, it provided at platform for unprecedented advances in space science and completed audacious missions such as the Hubble repair. Oh, and it was the most complex transportation system ever built.

On the down side, operating costs were vastly more than promised (which many see as 'shackling' NASA to low Earth orbit by eating up large proportions of its budget), it's launch frequency and flexibility again never matched the promises, and 14 astronauts lost their lives due to it, which I believe is the single largest loss to any particular launch system (I think early Soyuz was 4 fatalities, but nothing since the early days); at the end, wasn't the estimate of catastrophic failure down to something like 1 in 50 flights?

Yours,
Miranda.

It was 133 successful flights and 2 catastrophically failed flights. Naturally that was not their expected design failure rate. The foam impact can be considered a rocket launch failure, because of the need to have an external tank in the first place, and the failed O-ring is definitely a failure inherent to solid fuel ICBM rockets. 

The idea of the SSTO is to reduce costs, but with rocket engine technology, the risk is inherently high. Play with rockets and you'll get burned.  That is why developing the Sabre is so important.  It reduces system size and risk.

The difficulty with single stage to orbit is it shaves structural margins razor thin, especially once you account for recovering and reusing the stage.

It may sound retrograde for me to say so,  but what we need to do is re-incarnate HOTOL in a non-payload version,  just for the purpose of testing and developing the SABRE.  It has the right geometry for the rocket nozzles plumes, in the current cylindrical geometry of Sabre, and it could have a delta wing in a Space Shuttle / Buran / Boeing X-37 re-entry hypersonic glider configuration.  

We already understand the fluid dynamics and thermal protection system of the Shuttle.   With minimal effort and existing materials we can develop an X-37 looking unmanned engine test bed.

As Ms Miranda wrote, the impression was that the original HOTOL was close enough in SSTO horizontal takeoff mode, and the only objection was the finding of having a heavy tail which in turn forced a body dynamic centre to be pushed very far back, which resulted in a small payload.  But what if there is no payload?

https://en.m.wikipedia.org/wiki/HOTOL


If we can get away with carrying fuel and horizontal takeoff,  then fine,  but even if we can't carry the fuel, we can use booster rockets or a second stage used to substitute for the low speed flight, or perhaps even a single stage carried piggyback on a 747. There are more design options available.

https://en.m.wikipedia.org/wiki/Boeing_X-37


~ ~ ~

Just having a little fun with Photoshop  ;D

Basically, I'm picturing something like an X-37 with a SABRE engine mounted on top between two vertical stabilizers. Without a payload bay, this is basically a flying fuel tank with an engine. There should be no issue with the rocket plume in this case.  I'm unsure about the placement of the engine though.

Dear Admiral Wilhelm,
The two-stage approach, with both being recoverable, winged vehicles, is definitely s potential solution here, and of course this is exactly the approach SpaceShipOne took to win the X-prize. The only reason I can see why it's not been taken up for orbital craft is the cost of developing and building two vehicles. Wasn't this one of the very early ideas for the shuttle? As you mentioned, that would have removed the need for external tank and SRBs, removing the reasons for both accidents; with this design, the shuttle could still be flying today. Swiss Space Systems are currently working in such a design - http://www.space.com/21605-project-soar-swiss-space-plane-gaining-steam-video.html (http://www.space.com/21605-project-soar-swiss-space-plane-gaining-steam-video.html).

There has been much debate over the configuration of the sabre test-bed - maybe they should look back at the HOTOL configuration for these. As a little aside, at one point they thought of assisting HOTOL's launch by using a rocket-sled launch ramp; shades of of Fireball XL5 https://www.youtube.com/watch?v=u7LMlr9cWO4 (https://www.youtube.com/watch?v=u7LMlr9cWO4) ;)

Quote from: Peter Brassbeard on October 18, 2015, 08:51:24 PM
The difficulty with single stage to orbit is it shaves structural margins razor thin, especially once you account for recovering and reusing the stage.

Definitely; everything on Skylon, if it is ever to fly, will be pushed to the absolute limit. If only the Earth had the gravitation of, say, Venus, it would be a lot simpler...

Yours,
Miranda.

The terrible beauty of Hurricane Patricia, the strongest-ever hurricane to hit the Americas on the Pacific side, as photographed by Astronaut Scott Kelly aboard the International Space Station

https://twitter.com/StationCDRKelly



Hurricanes are Mother Nature's own turbine engines, like a giant energy sink, converting the energy stored in warm air and moisture into mechanical energy.

As photographed from a geostationary weather satellite:

It seems that REL are receiving an influx of cash and expertise: http://spacenews.com/bae-takes-stake-in-british-air-breathing-rocket-venture/ (http://spacenews.com/bae-takes-stake-in-british-air-breathing-rocket-venture/).

Yours,
Miranda.

Quote from: Miranda.T on November 03, 2015, 06:46:56 PM
It seems that REL are receiving an influx of cash and expertise: http://spacenews.com/bae-takes-stake-in-british-air-breathing-rocket-venture/ (http://spacenews.com/bae-takes-stake-in-british-air-breathing-rocket-venture/).

Yours,
Miranda.

That would be good news, but unwritten are the strings attached to that money.  The article specifically states that "[BAE] had agreed to purchase a 20 percent equity stake in single-stage-to-orbit engine designer Reaction Engines Limited (REL) and would provide the company with 'industrial, technical and capital resources' for ground-based testing of a prototype".

The critical phrase is "ground-based testing of a prototype." Remember that Mach 5+ wind tunnels are practically non existent, and have extremely small test chambers. because it takes an enormous amount of energy to accelerate air to those speeds.  Moreover, once you do, the gases in the test chamber are not air, but rather a decomposing soup of molecules that have been super saturated with energy - and that means that heat transfer experiments are useless in ground based experiments outside of rocket sleds. True hypersonic testing usually involves mounting something on a sounding rocket an launching it, so the air at high Mach numbers is pristine and cool.

The SABRE engine, on the other hand employs a turbo-machinery based hybrid-cycle, and therefore you can simply reproduce the performance of half the cycle in ground based facilities.  Also, even for a ramjet, the flow inside the engine downstream from the diffuser is subsonic, so again, you can reproduce that more easily in ground facilities.

In other words, the funded testing pertains exclusively to SABRE and not to SKYLON.

Also, it seems that we, Americans, are of a single mind:

Quote from article above

QuoteThe U.S. Air Force Research Laboratory subsequently looked at REL and SABRE and said the technology shows promise, with the caveat that it might be better suited to an less-challenging architecture  employing two stages to reach orbit.

My agreement with their opinion is no accident, perhaps.  The Air Force Office for Special Research, AFOSR (a division of the same office as above) used to provide the funding for my undergraduate research project and that of two other graduate students in my office back in 1998, plus two graduate students at Purdue University (where the actual Mach 4 wind tunnel was).  That AIAA paper, above which I wrote, was funded by the AFOSR (note not all military projects are classified - many are open to the public including international students), and was based around testing for Mach 4 low altitude self propelled anti tank projectiles.  So this opinion by the Air Force doesn't surprise me.  ;D

I'd be happy to participate in the development of a test vehicle if somebody made a little room for me.... But that's the $64K question, ain't it?  :) :-\

I'm determined to get Steampunk Sub-Orbital (SSO) to work. After having no volunteers to travel in my Jules Vern inspired multi-stage accelerated projectile (after all, I can't do it, I need to be back in mission control...), I've decided to try a different approach - an airship launched rocket-plane.

This is an idea that is kicked around in the 'real world' as a possible launch system, and seems right up Steampunk's street. The airship part should be possible; a bit of focused research to to develop an ultra-high altitude version, but how could a rocket be produced with Victorian/Edwardian technology? It is, after all, rocket science, and how long did it take brilliant engineers such as Goddard, Korolev and Von Braun* to get the technology working? Then I thought of a, if not primitive, then at least a more straightforward example of a rocket-powered craft - the Me 169 Komet. Could, with the appropriate knowledge, the materials available in the early 20th century be up to building something along the lines of the Komet? Then, with a high-altitude launch and assuming the evil fuel used didn't blow up or leak and kill the pilot, I wonder how high the craft could have been pushed?

Then there's all sorts of interesting questions over pressure suits for the pilot (and indeed coping with the pressure differential for the rocket's mechanism) and the mechanism of slowing the whole thing down for a safe descent (maybe air-brakes or a variant of what SpaceShip One used). Note there's no need for too fancy a material to protect the craft against heating on re-entry, as this is just sub-orbital.

Anyway, I shall throw it open to debate...

Yours,
Miranda.

* Just focussing on the engineering and ignoring actions taken during World War 2...

You know? That is quite a workable idea.  Do you remember all those YouTube videos about students launching balloons with cameras,  and so forth? Why not use a balloon to lift a small rocket plane?  I bet I can accelerate to any Mach number I desire if the craft is small enough. If I could self level the rocket (dropped within the atmosphere for positive dynamic control) .   It would have to be a hypergolic fuel rocket (solid rocket) powered craft so no oxygen tanks are required.

For Victorian technology I'd envision stratosphere capable rigid airships like the USAS Orca,  but weather balloons to carry experiments to low orbit altitude, and then drop launch self leveling rockets from that altitude. The thing is it has to be a rocket and not a plane,  because practical aerodynamic knowledge was sparse.

The Komet's rocket seemes to have been a bit of a hybrid between a solid fuel which gave oxygen for a liquid one ('T-Stoff' and 'C-Stoff' - or possibly the other way aorund!). The reason I was thinking rocket plane was to allow it to be dropped and then fired, with the control surfaces taking it from level to rising flight. If we could stretch the era's knowledge base to rocketry, could we stretch to a bit more understanding of aerodynamics?

Yours,
Miranda.

Quote from: Miranda.T on November 10, 2015, 11:12:54 PM
The Komet's rocket seemes to have been a bit of a hybrid between a solid fuel which gave oxygen for a liquid one ('T-Stoff' and 'C-Stoff' - or possibly the other way aorund!). The reason I was thinking rocket plane was to allow it to be dropped and then fired, with the control surfaces taking it from level to rising flight. If we could stretch the era's knowledge base to rocketry, could we stretch to a bit more understanding of aerodynamics?

Yours,
Miranda.

Well there are several ways to do this depending on how high you climb and how far you're willing do drop before attaining positive attitude control.  The last thing you want is an uncontrolled tumble.  But the problem is that the higher you climb before launching the rocket or rocket plane, the less chance you have of using any aerodynamic control at all, so you have to make a choice what kind of vehicle you want.

For a controlled descent to Earth, the latter method is preferable.  Perhaps this is where a mid-atmospheric (115 km altitude) vehicle starts resembling Burt Rutan's Spaceship One? I'd expect that there'd be an initial drop whereby if you let it drop, you may attain aerodynamic control, and the fire the rocket to a maximum Mach number of 3.  The terminal speed altitude being key here, as the speed of sound (and hence the Mach number) is very sensitive to the altitude, and as the density of the atmosphere greatly increases, so this would determine your maximum speed.

But for a high altitude hypersonic trial, preferably I'd try to not have a long drop and instead try to gain rocket powered (hypergolic) attitude control right away.   Then the ascent would be dominated by rocket propulsion, with a subsequent burn designed to attain the maximum speed possible. At this stage the vehicle looks more like the X-15 maintaining a stable flight in the Mach 5 range (speed= 5000 km/hr speed of sound=1000km/h at 145km~90 mi of altitude. Then the descent would be as a glider, still far too slow compared to an orbital re-entry vehicle like the Space Shuttle, but very much more like the descent of the German WWII Era Silbervogel, using a lifting body design to create a cyclical lift ("bouncing") from the tenuous atmosphere.

I was thinking the craft would be a bit X-15 like. One thing though - presumably the airship is hydrogen-filled to get maximum lift, so you wouldn't want to be igniting the rocket too soon after drop...

Yours,
Miranda.

Quote from: Miranda.T on November 11, 2015, 07:15:23 PM
I was thinking the craft would be a bit X-15 like. One thing though - presumably the airship is hydrogen-filled to get maximum lift, so you wouldn't want to be igniting the rocket too soon after drop...

Yours,
Miranda.

That's an interesting question, given that the oxygen content of a rarefied atmosphere is very low... To be honest I don't know the answer as to exactly how severe the risks are.  Even  without combustion (in which case the lingo is that this would be a detonation, not an explosion)  you naturally don't want to puncture the gas bag; you want the airship to be away from the rocket plume.

There's bound to be a graph or table somewhere detailing the amount of oxygen necessary for hydrogen to combust...

Not a graphic, but a yahoo answers page on the subject:

https://answers.yahoo.com/question/index?qid=20100522105309AA1bWkS

Quote from: MWBailey on November 12, 2015, 03:28:37 AM
There's bound to be a graph or table somewhere detailing the amount of oxygen necessary for hydrogen to combust...

Not a graphic, but a yahoo answers page on the subject:

https://answers.yahoo.com/question/index?qid=20100522105309AA1bWkS (https://answers.yahoo.com/question/index?qid=20100522105309AA1bWkS)

Indeed. You start by considering the molar density for a given altitude. How far you get from a stoichiometric mixture will affect flammability. But it;s a bit more complicated than that. The molecules have to interact with one another (be close enough) to actually propagate the combustion reaction. Mother Nature being what it is, this question is substantially more complicated than just calculating molar fractions, and sufficiently complicated that to date we have graduate level academic research on the subject:

https://www.fire.tc.faa.gov/pdf/TC-TT-14-36.pdf (https://www.fire.tc.faa.gov/pdf/TC-TT-14-36.pdf)

This is a Thesis paper (brings back memories  ;D ) from some graduate student, regarding the Lower Flammability Limit (LFL), and  Upper Flamability Limit (UFL) for hydrogen as a function of altitude.  The most interesting part, actually is the student's introduction chapter on the background history for his research.

There are a lot of factors which affect flammability.  One is that you have to define exactly what "flammable means." 

First, for all purposes we assume Hydrogen will detonate (aka conflagrate), meaning there is a flame that propagates very quickly, as opposed to explode, which is when all the hydrogen molecules simultaneously react at the same time. So explosions and detonations are two different things. Here we are talking about detonations.

Second, all gases can ignite; but whether they can maintain a chain chemical reaction is another thing. There are many factors that affect this

What was found in late 20th. research (also supported by this student;s findings) is that the LFL, expressed in percent minimum hydrogen -by volume- needed to detonate was about 4% at sea level, and as the pressure decreased at altitude, at say the lower stratosphere, 30 000 ft, then that minimum actually decreased to 3.5%. Then as altitude increases further to 17km of altitude (55 000 ft) and oxygen density decreased, then the LFL would spring back up to 4%.

The UFL does something similar going from 78% hydrogen by volume at 1 atmosphere, peaking at close to 79% at 15 000 ft and the sharply going down to 77% at 40 000 ft. and 76% by 55 000 ft.

This all means that hydrogen actually has an easier time detonating between 15 000 ft  and 30 000 ft than anywhere else! But go higher and the tables turn making it more difficult to detonate.

Presumably then as you climb higher the LFL just continues increasing, until either there simply is not enough percentage hydrogen to ignite, or the percentage of hydrogen, no matter how low would be "too rich" of a mixture.  In other words both LFL and UFL actually "merge." because the molecules are too far apart , and propagation of flame is very very slow according to that definition).

My guess is that in the stratosphere with an airship travelling at very low speeds (basically stationary with respect to the rocket) you still are at a very high risk for detonation -actually a bit higher than on the ground. This situation very much pertains to the Spaceship One type of vehicle.

If the USAS Orca was launching a "Steampunk One" spaceship at 35 000 ft. then this would be a severe risk of gas bag breach and detonation  ;)  ;D

For the X-15 type of vehicle, at much higher altitudes your risk significantly goes down. But the question is how far up I need to go. That I don't know off-hand. If the balloon went "all the way up," then there is no uncertainty, though...

According to atmospheric data, the relative mixture of atmospheric gases is more or less constant up to 100 Km of altitude, basically, and if you go higher than the heavy gases begin to separate from the lighter gases; this is about the edge of space.  Around 90Km of altitude (relevant to the latitude ceiling of the Silbervogel and X-15) the pressure is about 3X10^-5 atmosphere, 3/100000th the pressure of air on the ground, and the density is 3X10^-6 or 3 millionths of the density in the atmosphere.  At this altitude, you definitely can't sustain a hydrogen flame without the hydrogen and oxygen being "over-pressured" relative to the ambient and coming from a rocket nozzle.

http://ruc.noaa.gov/AMB_Publications_bj/2009%20Schlatter_Atmospheric%20Composition%20and%20Vertical%20Structure_eae319MS-1.pdf (http://ruc.noaa.gov/AMB_Publications_bj/2009%20Schlatter_Atmospheric%20Composition%20and%20Vertical%20Structure_eae319MS-1.pdf)

But this is cheating, because we know we are going to "drop" the X-15 vehicle a bit before climbing again. I'm inclined to tale a look at the UFL figures, because I imagine that a breached hydrogen gas bag presents a "fuel rich" mixture in the atmosphere presumably at risk of ignition at very low pressures. So I'm looking for Hydrogen UFL at altitudes above the stratosphere.


I'm kind of tired right now, as it's well past midnight ... let me sleep on it a bit  ;) 

(theres no "tired smiley face?)

Expanding on the idea of SSO... For those with access to UK television, Channel 4 this Sunday at 8 pm (GMT) has a documentary about the World War 2 'super gun' with the mechanism of multistage acceleration which I though might be used for launching a capsule.

For the airship launch, I've been mulling over the idea of two airships arranged parallel to each other and joined by a framework incorporating a steam or compressed air launching rail; this rail would arc up at the end to launch the rocket-plane upwards (a little like the 'ski-jump' used on UK aircraft carriers to launch Harriers). Then the rocket-plane could be launched to a safe distance from the airships before rocket ignition but also be on an upwards trajectory.

Yours,
Miranda.

Quote from: Miranda.T on November 19, 2015, 07:18:11 PM
Expanding on the idea of SSO... For those with access to UK television, Channel 4 this Sunday at 8 pm (GMT) has a documentary about the World War 2 'super gun' with the mechanism of multistage acceleration which I though might be used for launching a capsule.

For the airship launch, I've been mulling over the idea of two airships arranged parallel to each other and joined by a framework incorporating a steam or compressed air launching rail; this rail would arc up at the end to launch the rocket-plane upwards (a little like the 'ski-jump' used on UK aircraft carriers to launch Harriers). Then the rocket-plane could be launched to a safe distance from the airships before rocket ignition but also be on an upwards trajectory.

Yours,
Miranda.

Sounds interesting, but I wonder if it is necessary to have a catapult or launch rail at all... If I understand correctly your preoccupation is with the rocket plume hitting the gas bag.  A missile or any rocket dropped from a relatively slow moving vehicle basically poses no threat to the launching pad, provided it is allowed to drop for a small distance before firing the rocket.  How many tens or hundreds of feet of altitude would be lost upon dropping the rocket before it is ignited?

My latest creation.
(https://goo.gl/photos/syLav69RQUcy2Ki39)
... having a hard time finding a test pilot.

Quote from: Peter Brassbeard on December 16, 2015, 04:40:16 PM
My latest creation.
(https://goo.gl/photos/syLav69RQUcy2Ki39)
... having a hard time finding a test pilot.

Don't look at me, man.  I just dream them up. The closest I ever came to fly was on that Cessna 150 flight simulator in college. The last time I was on one, I nearly broke it...

I was supposed to do a test run for a high power climb, a maximum range glide, several turns, and other flight mission phases, while two team mates gathered data for the Flight Dynamics laboratory class.  Strictly matching physics to experimental data based on engine size, wing size, power settings, etc.  This is just Isaac Newton's stuff, really simple maths, more like High School physics applied to the dynamics of an airplane, actually a fun class.

However, my two team mates, a guy and a girl, were like misbehaving monkeys when they were together, and at that time they decided to pull a prank on me, right after I levelled off from the climb. Once I was in cruise, they messed with every single control and cranked up the turbulence and crosswinds to the maximum allowable.

While I was trying to keep the craft level, with the controls at my hand shaking like I had a really bad case of Parkinson's disease, I heard over my shoulder, in a real condescending tone of voice: "Stop shaking the stick like that. What's the matter John? Haven't you ever flown before?"  Then the pair started laughing while the plane was on a steep dive. I didn't even know how to get off the damn machine  ;D

GAAAAAAH!  google messed me up again.
(https://lh3.googleusercontent.com/AJ0v5eG61Zc-aeY1L4dTE9ePnLRs6hCd5bCN2EpTS8g08TWO69j6Frpo2B_RmrXwlReQn1M-HPY=w519-h470-no)

 ;D

Interesting.  It's actually been done in the small drone category. Alas,  as the size of the craft gets bigger, you might find it becomes exponentially more difficult. A little gremlin by the name of Strouhal Number is responsible for that. The larger a wing is,  the slower it must flap to be efficient,modified also by the forward speed. Has to do with recycling lost energy from each flap by "back slapping" the outgoing vortex of air a second time in the right way to recover lost energy.  Through evolution,  animals developed the right flapping frequency. Compare insects and humming birds to condors,  for example.

Quote from: Miranda.T on October 05, 2015, 06:44:54 PM
Anyway, my thoughts on Steampunk supersonic flight. As shown in your picture, a bullet shape is nice and stable (if spinning) in flight, so let's go Jules Verne (or possibly Gerald Bull - https://en.wikipedia.org/wiki/Gerald_Bull (https://en.wikipedia.org/wiki/Gerald_Bull)) and do a sub-orbital by putting our passengers in a glorified shell. But what of the problem of squishing them to a thin red smear by the launch force? Well, I was watching a documentary a little while ago about one of Hitler's V-weapons that never saw service - a supergun that would have used staged explosions along the launch tube to accelerate the projectile. So, I'm thinking a massive launch tube (laid along the side of some convenient mountain), our intrepid aeronaut's capsule accelerated at multiple stages to keep down to say 4g max. I'll have to play with some numbers when I get a few moments to see if it might be feasible.

Yours,
Miranda.

We actually had some discussion of "space guns" (http://brassgoggles.co.uk/forum/index.php/topic,15735.msg334100.html#msg334100) back in 2009.
Five Gs is punishingly uncomfortable for humans, but considered
tolerable for about six minutes.

In other words - you might very well feel that you are about to
die but, likely as not, you will survive the experience.

Humans have been briefly exposed to as much as ten Gs and
survived.

http://science.howstuffworks.com/transport/flight/modern/physics-of-flight-quiz.htm?mkcpgn=i600000603&utm_source=facebook.com&utm_medium=social&utm_campaign=hswaccount (http://science.howstuffworks.com/transport/flight/modern/physics-of-flight-quiz.htm?mkcpgn=i600000603&utm_source=facebook.com&utm_medium=social&utm_campaign=hswaccount)

I recently came across this article :

Silanes as Fuel for Aerospace Propulsion
By Domenico Simone, Claudio Bruno and Bernhard
Hidding

- in :

Transactions of the Japan Society for Aeronautical
and Space Science, Space Technology
Vol. 7 (2009) No. ists26
(ISTS Special Issue: Selected papers from the 26th
International Symposium on Space Technology and
Science)
Pages 33-39.
(View / Download .PDF )
http://tinyurl.com/guhfc38 (http://tinyurl.com/guhfc38)

The keywords were :

Liquid Rockets,
Air-breathing Engines,
High Energy Density Fuel

Further rummaging hit upon the following pages :

Quote from: Khem Caigan on January 01, 2016, 09:18:40 PM
I recently came across this article :

Silanes as Fuel for Aerospace Propulsion
By Domenico Simone, Claudio Bruno and Bernhard
Hidding

- in :

Transactions of the Japan Society for Aeronautical
and Space Science, Space Technology
Vol. 7 (2009) No. ists26
(ISTS Special Issue: Selected papers from the 26th
International Symposium on Space Technology and
Science)
Pages 33-39.
(View / Download .PDF )
http://tinyurl.com/guhfc38 (http://tinyurl.com/guhfc38)

The keywords were :

Liquid Rockets,
Air-breathing Engines,
High Energy Density Fuel

Further rummaging hit upon the following pages :

Spoiler: ShowHide

Peter Plichta's One Stage Rocket Disc
@NASA Spaceflight . com
http://tinyurl.com/pgphzwx (http://tinyurl.com/pgphzwx)

" In 1933 the chemist Alfred Stock published his
book Hydrides of Boron and Silicon in the United
States. During and following the First World War
he worked at the Technische Hochschule in Karlsruhe,
Germany and showed that silicon-hydrogen compounds
could be synthesized. Because the element silicon
is listed in the periodic table below the element
carbon, this result was actually expected. Stock
managed to reach a chain length of 4 silicon atoms,
with the first two silanes being gaseous, the third
and fourth liquid. All these silanes are very highly
prone to self-ignition.

In 1970 Peter Plichta disproved the textbook theory
that the higher silanes are unstable. One of his
achievements was to create a mixture of silanes with
the chain lengths 5 to 10 (Si5H12 to Si10H22). He
also managed to separate the oil into the individual
silanes by means of gas chromatic analysis. This
showed the surprising result that silanes with a
chain length of over 7 silicon atoms will no longer
ignite spontaneously and can thus be used for
commercial purposes. . .

It has been known since 1924 that nitrogen at a
temperature of 1400°C reacts with powdered
silicon to form silicon-nitride while emitting heat.
This material can resist temperatures of up to
1900°C, indicating a very high bonding strength
in the molecule. In contrast to silicon, carbon
atoms cannot burn for reasons of quantum
mechanics, which means that rocket fuel such
as kerosene, liquid hydrogen and hydrazine in
an air-breathing engine can do nothing with the
80% nitrogen contained in the air but agitate
it through the engine. . .

Peter Plichta got the idea of constructing a disc in
which jet-turbines attached to shafts would drive two
ring-shaped blade rings rotating in opposite directions.
This will cause the disc to be suspended by the air just
like a helicopter. The craft can then be driven sideways
by means of a drop-down rocket engine. When a speed of
over 200 km/h has been reached, the turbines for the
blade rings will be switched off and covered to enhance
the aerodynamic features of the shape. The craft will
now be borne by the up-draft of the air, just like an
aircraft is. This will also mean that the critical power
required for rocket ascent will not be necessary. When
the spacecraft is orbiting the planet, the N2/O2 mixture
of the air will first be fed in through a drop-down air
intake when the craft is still at a low altitude of 30
km (1% air pressure). This will be conducted to the
rocket motor and the craft will thus accelerate to a
speed of 5000-8000 km/hour. This is where a standard
rocket jettisons its first stage, because by then about
75% of the fuel has already been used up.

The disc on the other hand will continue to accelerate
to 20,000 km/h and will thus reach an altitude of approx.
50 km (1 per thousand of air pressure). The speed will
increase as the air pressure drops, so that the process
can be continued until an altitude of approx. 80
kilometres and 25,000 km/h can be maintained. In
order to reach the required speed of 30,000 km/h and
an altitude of around 300 km, only a single measure
of oxidation agent will be needed at the end.

In the hot combustion chamber silanes decompose
spontaneously into hydrogen and silicon radicals.
The hydrogen is burned by the oxygen in the air and
water formed. Because molecular nitrogen is very tightly
bonded, it must be preheated and subject to catalytic
dissociation. The extremely hot silicon radicals will
provide additional support for this process, which will
in turn lead to silicon nitride (Hf = -750 kJ) being
formed. In order to burn superfluous nitrogen, larger
amounts of Mg, Al or Si powder can be added to the
silane oil.

When the spacecraft is returning from space the
ceramic-protected underside of the disc will brake its
speed to approximately 500 km/h and the covering will
open again, while the blade rings will automatically
begin to rotate. The jet turbines will then be started
for the landing operation. "

Some slick YouTube presentations in German follow,
with scathing ( and occasionally on-point ) commentary
from the Forum members.

Complaints about the greater part of Plichta's work
only being available in German aside, I would be
interested in knowing how his long-chained liquid
silane fuel "doped" with powdered metals perform in
comparison with conventional rocket fuels such as
kerosene and hydrazine, and what ( if any ) chance
there is of seeing long-chained liquid silane-fueled
engines on our highways in the near future.

[ Edit 1/2/2016 : The articles also mention
silicon nitride as a by-product of combustion.
That may be well and good for purposes of
rocketry, but can we expect any crust or
scale accumulation in a turbine or some
other engine burning liquid silanes for
fuel? ]

Miethe provided the inspiration for Plichta's
craft, and you'll find a description of
Plichta's vehicle at the bottom of the page
below :

Miethe Elektrische Luft Turbine
Unmanned V-7
by Rob Arndt
http://tinyurl.com/hc7594f (http://tinyurl.com/hc7594f)

Turning Sand into Fuel
- Silicon Oil as an Energy Carrier
@ Hasselberger . com
http://tinyurl.com/y8qrwyk (http://tinyurl.com/y8qrwyk)

Note :

You need to sign up to view the patents
available on FreePatentsOnline.

Signing up is free, and I happen to like
the search engine at FPO better than that
of the USPTO or that of GooglePatents.

Below are a few links to the relevant patents :

Method and Apparatus for Operating
a Gas Turbine with Silane Oil as Fuel
United States Patent 5996332
Inventor: Peter Plichta, Dusseldorf, Germany
Assignee: Klaus Kunkel, Ratingen, Germany
Filed: 01/30/1998
Published: 12/07/1999

Abstract :

The invention relates to a method of driving a
shaft by reaction of silanes, preferably silane
oils, with air in a double combustion chamber and
an associated drive mechanism.

The hydrogen of the silanes reacts in the first
combustion chamber with an insufficient level of
oxygen of the air supplied, thereby producing high
temperatures.

At said high temperatures, the nitrogen from the
air supplied reacts with the silicon of the silane
to form silicon nitride.

The resultant combustion gases and dust and the
non-combusted hydrogen are mixed in the second
combustion chamber with a large quantity of cold
compressed air, the hydrogen undergoing late burning,
and they subsequently enter a turbine chamber to
actuate turbine blades connected to a shaft.

The method is particularly environmentally-friendly
since no toxic or polluting waste gases are produced.

Free to Read / Download
@ FreePatentsOnline
http://tinyurl.com/htyo6j5 (http://tinyurl.com/htyo6j5)
===================
Reusable Spacecraft
Inventors: Peter Plichta; Walter Buttner,
both of Dusseldorf, Germany.
Assignee: Klaus Kunkel, Dusseldorf, Germany
United States Patent 5730390
Filed: 11/13/1995
Published: 03/24/1998

Abstract :

A reusable space craft having a disk-shaped casing
which receives buoyancy upon horizontal travel through
a gas atmosphere and three drive systems on the casing.

A first drive system utilizes counter-rotating rotors
driven by jet engines on the periphery. A second drive
system utilizes a rocket rotor which can swing out from
the bottom of the casing into an inclined position. The
third drive system is a main thruster rocket at the center
of the bottom fueled by an Si5 to Si9 silane propellant.

Free to Read / Download
@ FreePatentsOnline
http://tinyurl.com/z8mcygo (http://tinyurl.com/z8mcygo)
==========================
Discus-Shaped Aerodyne Vehicle for Extremely
High Velocities
United States Patent 5836543
Inventors; Klaus Kunkel, HerbartStrasse 6A,
D-40882, Ratingen; Peter Plichta,
Dusseldorf, both of Germany
Assignee: Klaus Kunkel, Ratingen, Germany
Filed: 08/01/1996
Published: 11/17/1998

Abstract :

A discus-shaped aircraft is provided with a peripheral
jet arrangement for generating lift and, in the bottom
of the aircraft, at least one rocket engine supplied
with silicon hydride and compressed air and operated
under conditions in which the silicon hydride is reacted
with nitrogen of the compressed air to form silicon
nitride while the nitrogen of the silicon hydride
compounds reacts with oxygen to form H2O.

Free to Read / Download
@ FreePatentsOnline
http://tinyurl.com/jtjhxxh (http://tinyurl.com/jtjhxxh)
===========================
Process for Operating a Reaction-Type Missile Propulsion
System and Missile Propulsion System
United States Patent 5775096
Inventor: Peter Plichta, Bruhnstrasse 6a,
D-40225 Dusseldorf. Germany
Filed: 07/18/1996
Published: 07/07/1998

Abstract :

A method for accelerating a vehicle in the atmosphere,
space or aerospace includes the steps of supplying a
propellant having silicone hydride compounds into a
combustion chamber, compressing air and delivering
compressed air into a ring formed with a plurality of
circumferential orifices which open into the combustion
chamber, reaching thereby temperatures of about 3000°C.
cracking nitrogen molecules present in the air at the
temperature which attack the silicon atoms to generate
great mass.

Free to Read / Download
@ FreePatentsOnline
http://tinyurl.com/zb3vzz2 (http://tinyurl.com/zb3vzz2)
===========================

Thank you for posting this Mr.  Caigan.   I've started reading the article on the silane based LR fuel. They start by taking advantage of lower temperatures for  complex silane molecule decomposition and wider liquid temperature ranges (for compact storage),  with an additional storage of energy due to positive enthalpy of formation, and then wrap it all up the claim that there are no dangerous radicals from combustion (not sure if I believe that. Fast combustion is a very messy process, chemically speaking),  but it looks interesting.

So far from what I gather they are basically claiming that fuel-rich mixtures above stoichiometric (equivalence ratio of 1) tend to give very high specific impulse (thrust efficiency) over a wider range of fuel rich mixtures; ie this fuel "likes" rich fuel mixtures and can operate well for a number of rich fuel-air ratios, whereas hydrocarbons drop their efficiency sharply when you are even a bit above a stoichiometric mixture (equivalence ratio of 1), and doing it with lower combustion temperatures.  Because energy is needed to form (manufacture) the complex silanes, when these break down in combustion, they return some of the energy you used in making the molecules in the first place.

So basically you can use lighter engines with the lower temperatures and the energy density of the fuel is higher, for smaller fuel tanks, if I understand correctly.  Practically for the engines, if indeed the combustion temperatures are lower, and the fuel remains liquid over a greater temperature range, then you can avoid having to circulate liquid hydrogen with pumps on the bell, or at least your pumps can be smaller, and your rocket nozzle bells lighter both by material and cooling pump size.  

That is one of the reasons that the Russians have been successful with their rocket technology, because they advanced bi-propellant technology and their rockets operate at lower temperatures, saving weight. When I was in graduate school, the analytical theory books on combustion were actually written in Russian (!).  Believe it or not, the Russian were slightly ahead of us in combustion at the end of the Cold War, and to avoid getting those rocket engines into unfriendly hands, out own government took to buying the Russian engines for some of our own military systems.  Now the Russians don't like us, and so we have to finish developing our rocket technology and why not?  Developing a new fuel technology might help a lot....

Good idea to reduce the weight of those nozzles and increase the specific impulse.  Pair that with aerospike technology and you get an engine that can operate at a greater number of altitudes and be more forgiving about the specific fuel mix ratios - all of it leading to a greater overall efficiency in propulsion.

Now the $64000 question is: How expensive is it going to be to develop the infrastructure to develop silane fuels?

Quote from: J. Wilhelm on January 05, 2016, 08:05:36 PM
Now the $64000 question is: How expensive is it going to be to develop the infrastructure to develop silane fuels?

It looks to me rather as if the infrastructure
is already in place. And, predictably, the bulk
of the larger, long-chain silanes are already
being produced in China.

First dibs on all that Helium-3 on the Moon,
and suchlike.

Silane Production Unit

" GT Advanced Technologies offers a complete
silane production unit designed as a
standalone facility to produce VLSI grade
silane for semiconductor and solar markets.

GT's silane production plant is constructed
using efficient structural modules that
decrease site work and reduce installation
time. The silane production module, which
includes work practice control and
standardization, provides flexibility
through scalability to speed start-up while
lowering cost. GT's silane production module
can begin delivering quality silane within
24 months. "

@ GT Advanced Technologies . Com
http://tinyurl.com/gq9cge8 (http://tinyurl.com/gq9cge8)

" This report presents data on the current
silane market. Published and public
information on 22 preparative methods for
monosilane and higher silanes are reviewed.

...The silane process developed by Union
Carbide Corporation under the DOE/JPL
Flat-Plate Solar Array Project is summarized,
including the purification
steps.

A section on the status of silanes in Japan
is also included. "

( Download .PDF @ Nrel . Gov )
http://tinyurl.com/j3n2lbm (http://tinyurl.com/j3n2lbm)

Chemical Book
Pentasilane

Global Suppliers :

T&W GROUP CHINA
Shanghai Gileader Advanced Material Technology Co.,Ltd CHINA
Chizhou Kailong Import and Export Trade Co., Ltd. CHINA

@ Chemical Book . Com
http://tinyurl.com/hkxqacg (http://tinyurl.com/hkxqacg)

A few more articles of related interest :

New Approach for Single Stage Ascent to Orbit :
Silicon Based Fuels for Space Flight
by David Padanyi-Gulyas and Andras D. Bodo
Nitronics Aerospace Technologies, LLC
2005-01-3412
( .PDF @ Academia . Edu )
http://tinyurl.com/zve48su (http://tinyurl.com/zve48su)

See also :

Polysilanes : all-rounder base materials in
PhotoVoltaics
City Solar Technologie GmbH & Co. KG
Bitterfeld-Wolfen, Nov 15, 2007
( .PDF downloadable here : )
http://tinyurl.com/zjm5tbt (http://tinyurl.com/zjm5tbt)

Let me preface this by saying that I have no
proprietary interest in City-Solar whatsoever
- I am providing this link as an example of the
sort of mischief that folks are already getting
up to with polysilanes out there in the market
place, and with a mind toward benchmarking
just how much progress has been made toward
providing the buckets of polysilanes necessary
to create and support sustainable orbital and
/ or lunar factories.

This company was founded in 2003, and they
have been up-scaling their production facilities
ever since.

They are in the business of producing photovoltaic
"solar panels", and they are developing liquid
polysilanes as the "enabling technology" for
"Printable electronics" and "Electronic precursors".

Example : Seiko Epson

Solution-processed silicon films and transistors
Nature 440, pages 783-786,
April 6, 2006
http://tinyurl.com/zv9dbg3 (http://tinyurl.com/zv9dbg3)

Printed Electronics at Seiko Epson
@ Printed electronics World . Com
http://tinyurl.com/hx3t8vd (http://tinyurl.com/hx3t8vd)

" It has already been demonstrated that silicon
based devices can be produced from H-Silanes
with ink jet or spin coating processes.

This could revolutionize the production technology
of many electronic devices, if it would be possible
to produce the required amount of these silanes at
competitive cost. "

Si5H10 cyclo-Pentasilane is described in their
brochure as a "potentially disrupting new Si-coating
technology".

Back in the day, something "potentially disrupting"
was simply referred to as "revolutionary".

Cyclopentasilane Si5H10 is dissolved in Toluol and
used in both inkjet and spin coating for printed
electronics, which looks to be much simpler than
conventional photolithographic technology.

City Solar-Technology claims that they are capable
of producing the required silanes at competitive
costs with their plasma polymerization procedure,
or "Plasma-Polysilane technology" ( they employ
microwaves ).

I gather from the brochure that they are well-aware
of the potential of polysilanes as fuel but, at the
time this brochure was printed, they were unable
to produce enough material to address the needs
of that market.

Still, it is encouraging that high-demand products
such as "solar cells" and "microchips", are going to
require polysilanes in their production.

QuoteLet me preface this by saying that I have no
proprietary interest in City-Solar whatsoever

Are you sure there is no "Khem Caigan Industries, Ltd." out there?   ;)

"Taking Khemistry to the next level"

;D

Quote from: J. Wilhelm on January 12, 2016, 07:00:08 AM
Are you sure there is no "Khem Caigan Industries, Ltd." out there?   ;)

"Taking Khemistry to the next level"

;D

Apart from my duties as Curator of the Harry Everett
Smith Library, I am also the CEO and Chief Cook and
Bottle Washer at ZAPGARDEN.

But our remit is Electrometeorology, Perfumes, Paint
and Metallurgy.

Mostly ;)

I was booted off of Do-It-Yourself Drones (http://diydrones.com/) years ago
because I was recommending construction materials
that were suitable for hard vacuum.

Now we have "off-the-shelf' electromagnetic tethers
and ion engines in kit form that kids can install in
their CubeSats (http://www.cubesat.org/).

I expect that it won't be all that long until kids are
launching their own 3D Printers and Factory Bots
out to near-Earth asteroids and assembling their
own spaceplanes out of foamed metals and
such-like materials. And operational habitats /
refueling stations into the bargain.

And if some of those habs are decked out with
miles of brassy conduit and lots of wood veneer,
so much the better!

Hasten The Day!

Quote from: Khem Caigan on January 14, 2016, 08:32:58 AM
I was booted off of Do-It-Yourself Drones (http://diydrones.com/) years ago
because I was recommending construction materials that were suitable for hard vacuum.

(raises an eyebrow) What materials, pray tell, were they objecting to, and for what application?

Quote from: Peter Brassbeard on January 14, 2016, 04:52:15 PM

Quote from: Khem Caigan on January 14, 2016, 08:32:58 AM
I was booted off of Do-It-Yourself Drones (http://diydrones.com/) years ago
because I was recommending construction materials that were suitable for hard vacuum.

(raises an eyebrow) What materials, pray tell, were they objecting to, and for what application?

I recollect one post was about TEEK-H polyimide foam
used in aerogel composites for thermal insulation, and
another was about the Clevios (TM) PH1000 transparent
conductive polymer.

The idea was to provide a 'heads up' on Materials Of
Interest for folks that wanted to build drones capable of
withstanding the environment in Nearspace, LEO and GEO.

This was back in 2009. And it is all "Old Hat" these days
for folks assembling their own CubeSats, MicroSats and
NanoSats, &tc.

Breaking news:

Sierra Nevada Corporation's Dream Chaser mini-shuttle has been chosen as the third personnel and cargo vehicle to re-supply the International Space Station.

http://www.bbc.com/news/science-environment-35328544 (http://www.bbc.com/news/science-environment-35328544)

QuoteThe European Space Agency (Esa) says it is excited by its US counterpart's selection of a winged vehicle to resupply the space station. Nasa has extended contracts to existing commercial cargo carriers, Orbital ATK and SpaceX, but has added a third team: the Sierra Nevada Corporation (SNC). This new entrant wll fly an automated mini-shuttle called Dream Chaser.
Esa has agreements to co-operate with SNC, which should now lead to European companies providing components. Chief among these contributions will be the International Berthing and Docking Mechanism (IBDM) - a new system developed in Europe to join spacecraft together.

https://en.wikipedia.org/wiki/Dream_Chaser (https://en.wikipedia.org/wiki/Dream_Chaser)

QuoteThe Dream Chaser is an American reusable crewed suborbital and orbital[6] lifting-body spaceplane being developed by Sierra Nevada Corporation (SNC) Space Systems. The Dream Chaser is designed to carry up to seven people to and from low Earth orbit. The vehicle would launch vertically on an Atlas V rocket and land horizontally autonomously on conventional runways

Ugly little critter, isn't it?  I guess loveable like a bulldog  :D The actual orbiter will not have the Pitot probe "arbor" on the nose like this atmospheric flight test vehicle shows. There is interest from European companies to upgrade the design to a folding wing design that will allow the orbiter to fit in a cargo fairing used for the Ariane rocket, and other US launch vehicles. It is thought that there will be US and European versions of the craft. The original design called for the orbiter to be launched without protection on top of an Atlas V rocket.


The selection doesn't come without controversy, and it appears to have been the product of a drama worthy of a "soap opera" or "telenovella" plot:



I'm not exactly sure what exactly led to that decision being possibly reversed, or perhaps a change of heart by NASA during the year between January 5 2015 and yesterday January 15 2016

~ ~ ~

J. Wilhelm

My hope still lies with the amateur rocketry community
that continues to "push the envelope" out in the deserts,
lobbing their designs ever higher into orbit.

Really, all we need is an upgraded, Open Source version
of something like the old Titan II to give Rocketry Clubs
and/or Universities a crack at re-booting what used to be
called "the Space Race" - which has ( sadly ) devolved
into something rather more like watching paint dry.

zzzzZZZZzzzzzZZZzzzzz<snork>zzzzzZZZZzzzzz. . . .

[ Note to Sinter Klaas : A single-stage rocket with a
tankful of hexasilane and a supplementary tankful of LOX
to keep things perking along in vacuum would be nice. ]

Space Tourism: Regulating Passage
to the Happiest Place Off Earth
by Catherine E. Parsons
( Download .PDF @ Chapman Dot Edu )
http://tinyurl.com/jpvs9t8 (http://tinyurl.com/jpvs9t8)

A Few Dreamers Building Rockets in Workshops
by Preston Lerner
Popular Science, May 2003
( Free Preview @ GoogleBooks )
http://tinyurl.com/zlaqe8k (http://tinyurl.com/zlaqe8k)

Amateur Rocketeers Chase $10,000 Launch
Prize Offered by John Carmack
By Mike Wall, October 11, 2011
@ Space Dot Com
http://tinyurl.com/o7se3s9 (http://tinyurl.com/o7se3s9)

The Mojave Launch Lab :
A Community of Alternative Rocketeers
Who May One Day Dominate The Space Biz
by Stephen Joiner
-in-
Air & Space, April/May 2011
( Download .PDF & Friends Of Amateur Rocketry Dot Org )
http://tinyurl.com/jnbhcjg (http://tinyurl.com/jnbhcjg)

Carbon Origins :
From Hobbyist Rockets to a Space Tech Business
By Nathan Hurst
July 21, 2015
Make Magazine Dot Com
http://tinyurl.com/otere7e (http://tinyurl.com/otere7e)

"Interplanetary travel is now the only form
of 'conquest and empire' compatible with
civilisation. Without it, the human mind,
compelled to circle forever in its planetary
goldfish bowl, must eventually stagnate."

- Arthur C. Clarke, Voices From The Sky, page 12.
Pyramid Books, 1965.

I did get to play with model rockets as a kid.  The thing is,  I was never satisfied with it.  Thankfully I never tried some of the more dangerous ideas I had  :D ;D  Otherwise you'd be calling me "crispy"  or "stumpy"

If you pardon the very cheesy 1980's Rambo-style music, I just found this video from Sierra Nevada Corp.showing a computer animation of a typical mission to the International Space Station. It looks like the docking module will be disposable.

SNC's Dream Chaser® Cargo System: A Transportation System to Deliver Cargo to the ISS for NASA (http://www.youtube.com/watch?feature=player_embedded&v=eHvBUqfWDRs#)


From Geek Wire: http://www.geekwire.com/2016/nasas-backing-fuels-more-interest-in-dream-chaser-space-plane/ (http://www.geekwire.com/2016/nasas-backing-fuels-more-interest-in-dream-chaser-space-plane/)

Quote
The Dream Chaser is designed to be launched atop an Atlas 5 rocket, with its wings in a folded-up configuration for orbital deployment. The cargo version will be equipped with an unpressurized "trunk" in the back. The spaceship should be capable of carrying more than 5 tons of cargo to the space station. It's also expected to deliver payloads from orbit to NASA in just a few hours, touching down with a smooth runway landing.

That quick and gentle delivery method is one reason why the Dream Chaser is due to be added to NASA's cargo fleet of SpaceX and Orbital ATK space vehicles, starting in late 2019. The space station program's chief scientist, Julie Robinson, said that feature is attractive for handling biological samples from space – potentially including live experimental animals.

"It would be effectively like we're an airline. We own the Dream Chasers."

The financial terms have yet to be nailed down, but in his interviews, Sirangelo says there's a general sense that a contract for at least six spaceflights should be worth at least a billion dollars, if not more.

Quote
Sirangelo said two Dream Chaser space planes will be built for NASA's use – and maybe not just for NASA.

"It would be effectively like we're an airline," he explained. "We own the Dream Chasers. NASA is our priority client, so they would get priority use of the vehicle. However, when they're not using them, and as long as it doesn't interfere, we have the capability of using the same vehicles for other clients."

Those clients could include other space agencies that want to pursue their own orbital research programs, with or without access to the space station. And the Dream Chaser's basic design can be adapted to accommodate a crew rather than cargo.

Quote
For now, SNC is focusing on the cargo-only version, but Sirangelo said customers will eventually be able to choose from a wide range of Dream Chaser options.

"It's very similar to how an aircraft manufacturer like Boeing or Airbus plans their vehicles," he said. "They have a core vehicle built for the 747 or the Airbus 330 or 320. And they can have different missions for the same airframe. It could be a passenger vehicle, it could be cargo, it could be a military variant, it could be for firefighting or some type of scientific research. We've approached it the same way."

Those are the sorts of opportunities that SNC hopes to pursue in the future, and those are the sorts of inquiries that Sirangelo may well be getting – although he declined to provide details during this week's interview.

The bottom line is that after 10 years of development, NASA's contract announcement finally provided the critical mass to turn the Dream Chaser into a reality. "People now see that the vehicle will be built," Sirangelo said.

So what now? Later this year, a Dream Chaser prototype will be put through its second aerodynamic test glide through the atmosphere – analogous to the tests that were done in the late 1970s using the space shuttle prototype known as the Enterprise.

For the upcoming test, the prototype will be dropped from a helicopter, Sirangelo said. After that, the atmospheric tests will be conducted at higher altitudes, using a carrier system that has yet to be identified.

At the same time, SNC is working with one of its lead industrial partners, Lockheed Martin, to build the structures for its space-capable Dream Chasers. Meanwhile, the European Space Agency has signaled that it will go ahead with a $36 million investment in Dream Chaser construction.

In 2019, SNC expects to be ready to send its first flight into orbit, taking advantage of an Atlas 5 rocket reservation it made with United Launch Alliance two years ago.

2019 really isn't all that far away, based on what it takes to get a new spaceship working. But Sirangelo is confident that SNC and its "Dream Team" of more than 60 partners can meet the schedule. "I'm fortunate to be leading what I believe is the best team in the space industry," he said.

This report has been corrected to reflect the fact that that Sierra Nevada Corporation is headquartered in Sparks, Nev.

I perused their jobs web page and they don't seem to have to many jobs available for the moment. That's not surprising given the tumultuous history they had in the last decade. But perhaps in the very near future, and now having NASA and European monetary commitment there may be jobs available for "aerodynamicists" like me when they start drop testing the mock vehicle.  I may send my resume and see if per chance they keep it and not send it to the trash bin.

Quote from: J. Wilhelm on February 01, 2016, 03:05:31 AM
I perused their jobs web page and they don't seem to have to many jobs available for the moment. That's not surprising given the tumultuous history they had in the last decade. But perhaps in the very near future, and now having NASA and European monetary commitment there may be jobs available for "aerodynamicists" like me when they start drop testing the mock vehicle.  I may send my resume and see if per chance they keep it and not send it to the trash bin.

[ Addenda to my Note to Sinter Klaas : Along with that
single-stage rocket, I would really appreciate an Open
Source, upgraded version of the old Dyna-Soar (http://www.astronautix.com/craft/dynasoar.htm) (still
decades ahead of its time ) parked on top. ]

I'm not sure whether I'd qualify it as ahead of it'd time, but Dyna Soar was a logical and smart solution to the requirement of blunting in hypersonic vehicles to reduce heat transfer at the skin.

In hypersonics, the shape of your vehicle is intimately related to the thermal resistance properties of the materials you use. As an "aerodynamicist" my primary concern is achieving a controlled descent, approach and landing, with the landing being a notoriously difficult phase of the fight mission due to stability. The Space Shuttle also incorporates design elements from lifting bodies, but the chemically non reactive silica glass fuselage allows us to increase the size of the wing/lifting surfaces for added control.

All being equal, Dyna-Soar type designs remain very cool to look at. Having so much experience on this, I agree an open source Dyna Soar could be done.  Mind you,  it's nor like the knowledge is classified and closed to the public (with so much of it being a civilian project and tax-payer funded), and if you care to buy an airplane ticket and fly down to Austin, I can take you to the University of Texas Library system, where we can peruse original NASA / Rockwell International documentation on the Shuttle, for example.

Quote from: J. Wilhelm on February 01, 2016, 07:44:31 PM
Mind you,  it's nor like the knowledge is classified and closed to the public (with so much of it being a civilian project and tax-payer funded), and if you care to buy an airplane ticket and fly down to Austin, I can take you to the University of Texas Library system, where we can peruse original NASA / Rockwell International documentation on the Shuttle, for example.

Sucking down public money has never stopped a corporation at
the trough from taking out a patent, and not getting hit with a
patent infringement ( or at least getting away unscathed ) is
the whole point of the freely downloadable designs for trucks
and what-not that are available from sites such as
Open Source Ecology (http://opensourceecology.org/gvcs/%5Bi).

In other news, I may be moving my family back to Texas - by
way of a road trip.

Ironically, I don't fly.

Perhaps we will see you there - I'll be headed over to the Harry
Ransom (http://www.hrc.utexas.edu/) center to give the papers of Charles Henry Allan
Bennett (http://tinyurl.com/zrueot7) a thorough going-over.

Quote from: Khem Caigan on February 02, 2016, 03:53:09 PM

Quote from: J. Wilhelm on February 01, 2016, 07:44:31 PM
Mind you,  it's nor like the knowledge is classified and closed to the public (with so much of it being a civilian project and tax-payer funded), and if you care to buy an airplane ticket and fly down to Austin, I can take you to the University of Texas Library system, where we can peruse original NASA / Rockwell International documentation on the Shuttle, for example.

Sucking down public money has never stopped a corporation at
the trough from taking out a patent, and not getting hit with a
patent infringement ( or at least getting away unscathed ) is
the whole point of the freely downloadable designs for trucks
and what-not that are available from sites such as
Open Source Ecology (http://opensourceecology.org/gvcs/%5Bi).

In other news, I may be moving my family back to Texas - by
way of a road trip.

Ironically, I don't fly.

Perhaps we will see you there - I'll be headed over to the Harry
Ransom (http://www.hrc.utexas.edu/) center to give the papers of Charles Henry Allan
Bennett (http://tinyurl.com/zrueot7) a thorough going-over.

Keep me advised then. I no longer am in the university and I'm afraid my life is very humble at the moment, mostly limited to a 5 mile radius (as I have no car) where I live - though not too far from the university. I am trying to lift myself out of a decade long financial catastrophe after my family business collapse and grandfather's death, and I'm also currently stunned / dumbfounded by my inability to return to engineering. Perversely, some of my regular  customers at my current place of employment happen to be former professors and including one graduate supervisor. This is a time of great shame and fear for me, to be honest. But I have resolved that change must come fast, even if it means expatriation. But for the moment I'm alive, and I'd be happy to meet you and your family.  ;)

The "Spiral"So were the 60 years - the height of the space race and the Cold War. At this time the United States had an active project development Dyna Soar, which meant the creation of a hypersonic interceptor manned orbital reconnaissance bomber, the X-20.In response, the Soviet Union decided to create its own aerospace systems. In 1965, the corresponding instruction was given to the experimental design bureau 115 (OKB-115) named Alexander Mikoyan, where the study was headed by Chief Designer Gleb Lozino-Lozinski. The project was called "Spiral". He was to be the main argument for the possibility of war in the Soviet Union in space and from space.

The chosen scheme launch space plane and constructive solutions incorporated Lozino - Lozinsky , have given the project the USSR "Spiral" at a glance:In orbit, can be derived payload 9% of the total weight of the entire systemThe cost of output for each kilogram of cargo was 3.5 times cheaperRapid withdrawal of the orbital plane at any point on the globeLanding in all weather conditionsThe " Spiral" consisted of three main parts: the hypersonic booster aircraft ( GSR) , two-stage rocket booster and the orbital plane (OS). As planned Lozino - Lozinski , booster aircraft to the orbital plane at the back had to take off from the base airfield and accelerate to a speed of about 7500 km / h After reaching a height of 30 kilometers of the orbital plane was separated from the GSR and using a two-stage rocket booster accelerated to orbital velocity ( about 7.9 km / s). After that, the orbital plane went into orbit and performed one of their combat missions : reconnaissance , missile interception space targets " space-space " and the bombing of missiles " space-to- Earth" with a nuclear warhead. At its core, the orbital plane is a true space fighter .The orbital plane of the " spiral ", as well as booster aircraft was piloted . Place the pilot was a separate capsule, which in case of emergency situation was to separate and save the life of the pilot even in space .Closure of the " Spiral"Development of the project "Spiral" was in full swing, and in the second half of the 1970s , scientists led by Gleb Lozino - Lozinsky planned to begin flights fully manned aerospace systems "Spiral" . The case remained for small - to approve the draft in the top leadership of the USSR. But the minister of defense of the Soviet Union Andrei Grechko in the early 70s , instead approve the project "Spiral" , threw out all the documentation on it in the bin and said : "Imagination , we will not deal with ." Project of the USSR "Spiral" was closed.

http://www.buran.ru/htm/molniya.htm (http://www.buran.ru/htm/molniya.htm)

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Farmyman.info%2Fuploads%2Fposts%2F2013-01%2F1358746259_13337922.jpg&hash=040e6005229642a4f249cc9605a20041eed43482)

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Fm.gadzetomania.pl%2Fprotoplasta-411538-996f35bae2606%2C630%2C0%2C0%2C0.jpg&hash=07d818c09f23b9c760f1b2c4e6597ac81f5ff7d9)

Quote from: morozow on February 13, 2016, 12:41:41 PM
The "Spiral"So were the 60 years - the height of the space race and the Cold War. At this time the United States had an active project development Dyna Soar, which meant the creation of a hypersonic interceptor manned orbital reconnaissance bomber, the X-20.In response, the Soviet Union decided to create its own aerospace systems. In 1965, the corresponding instruction was given to the experimental design bureau 115 (OKB-115) named Alexander Mikoyan, where the study was headed by Chief Designer Gleb Lozino-Lozinski. The project was called "Spiral". He was to be the main argument for the possibility of war in the Soviet Union in space and from space.

The chosen scheme launch space plane and constructive solutions incorporated Lozino - Lozinsky , have given the project the USSR "Spiral" at a glance:In orbit, can be derived payload 9% of the total weight of the entire systemThe cost of output for each kilogram of cargo was 3.5 times cheaperRapid withdrawal of the orbital plane at any point on the globeLanding in all weather conditionsThe " Spiral" consisted of three main parts: the hypersonic booster aircraft ( GSR) , two-stage rocket booster and the orbital plane (OS). As planned Lozino - Lozinski , booster aircraft to the orbital plane at the back had to take off from the base airfield and accelerate to a speed of about 7500 km / h After reaching a height of 30 kilometers of the orbital plane was separated from the GSR and using a two-stage rocket booster accelerated to orbital velocity ( about 7.9 km / s). After that, the orbital plane went into orbit and performed one of their combat missions : reconnaissance , missile interception space targets " space-space " and the bombing of missiles " space-to- Earth" with a nuclear warhead. At its core, the orbital plane is a true space fighter .The orbital plane of the " spiral ", as well as booster aircraft was piloted . Place the pilot was a separate capsule, which in case of emergency situation was to separate and save the life of the pilot even in space .Closure of the " Spiral"Development of the project "Spiral" was in full swing, and in the second half of the 1970s , scientists led by Gleb Lozino - Lozinsky planned to begin flights fully manned aerospace systems "Spiral" . The case remained for small - to approve the draft in the top leadership of the USSR. But the minister of defense of the Soviet Union Andrei Grechko in the early 70s , instead approve the project "Spiral" , threw out all the documentation on it in the bin and said : "Imagination , we will not deal with ." Project of the USSR "Spiral" was closed.

http://www.buran.ru/htm/molniya.htm (http://www.buran.ru/htm/molniya.htm)

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Farmyman.info%2Fuploads%2Fposts%2F2013-01%2F1358746259_13337922.jpg&hash=040e6005229642a4f249cc9605a20041eed43482)

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Fm.gadzetomania.pl%2Fprotoplasta-411538-996f35bae2606%2C630%2C0%2C0%2C0.jpg&hash=07d818c09f23b9c760f1b2c4e6597ac81f5ff7d9)

Now that's the spirit! Thank you for posting. I didn't know many of the details regarding this Spiral project.

It seems we are back in the days of "lifting bodies" again, since the Space Shuttle and Buran became a distant memory. I need to see if I can somehow get into the Sierra Nevada Corporation, but in spite of my education I have no experience.  Those small companies usually don't look for people with little experience...

That's amazing that they were thinking of a two-stage booster system, and the orbiter. Combined plane and rocket. That is an unusual configuration. At 7500 km/h that already is significantly faster (and higher) than the X-15 (5000 km/h). 

Here's a great picture of the MiG-105 Spiral

(https://upload.wikimedia.org/wikipedia/commons/thumb/2/22/MiG-105-11a.JPG/1024px-MiG-105-11a.JPG)

It's closest cousin would be the X-20 Dyna Soar below is a comparison between the two:

Differences between Dyna-Soar and Spiral
https://en.wikipedia.org/wiki/Mikoyan-Gurevich_MiG-105

Quote
Although having basically the same mission, Dyna-Soar and Spiral were radically different vehicles. For example:

While the X-20 Dyna-Soar was designed for launch atop a conventional expendable rocket such as the Titan III-C or Saturn I, Soviet engineers opted for a midair launch scheme for Spiral. Known as "50 / 50", the idea was that the spaceplane and a liquid fuel booster stage would be launched at high altitude from the back of a large, airbreathing mothership travelling at hypersonic speeds. The mothership was to have been built by the Tupolev Design Bureau (OKB-156) and utilize many of the same technologies developed for the Tu-144 supersonic transport and the Sukhoi T-4 Mach 3 bomber. It was never built.

Dyna-Soar was designed as a lifting body, while Spiral was a conventional delta that featured an innovative variable-dihedral wing. During launch and reentry, these were folded upward at 60 degrees. After dropping to subsonic speeds post-reentry, the pilot lowered the wings into the horizontal position, giving the spaceplane better re-entry and flight characteristics.

Spiral was built to allow for a powered landing and go-around maneuver in case of a missed landing approach. An air intake for a single Kolesov turbojet was mounted beneath the central vertical stabilizer. This was protected during launch and re-entry by a clamshell door which opened at subsonic speeds. By comparison, Dyna-Soar was designed primarily for a once-off, unpowered deadstick landing.

High temperature superalloy metals such as niobium, molybdenum, tungsten and rene 41 were to have been used in the heatshield structure of the X-20. Spiral was to have been protected by what Soviet engineers termed "scale-plate armour": niobium alloy ВН5АП and molybdenum disilicide plated steel plates mounted on articulated ceramic bearings to allow for thermal expansion during reentry. Several BOR (Russian acronym for Unpiloted Orbital Rocketplane) craft were flown to test this concept.

In the event of a booster explosion or in-flight emergency, the crew compartment of Spiral was designed to separate from the rest of the vehicle and parachute to earth like a conventional ballistic capsule; this could be done at any point in the flight. Such an escape crew capsule was also considered for Dyna-Soar, but American engineers eventually opted for a solid-fuel escape rocket that would kick the spaceplane away from an exploding booster, hopefully saving both pilot and spacecraft.

Much like the Space Shuttle, Dyna-Soar was designed with a small payload bay behind the pressurized crew module. This could be used for lofting small satellites, carrying surveillance equipment, weapons or even an extra crewmember in a pop-in cockpit. Spiral, on the other hand, was intended to carry only its pilot.

Both Dyna-Soar and Spiral were designed to land on skids. The landing skids on Dyna-Soar were designed to deploy from insulated doors on the underside of the vehicle, like a conventional aircraft. Soviet engineers designed the landing skids on Spiral to deploy from a set of doors on the sides of the fuselage just above and ahead of the wings.

I wonder how they planned to propel the space plane past X-15 speeds, with air-breathing engines, and about the mating and separation of the rocket booster - having to tackle many of the same problems that we've discussed earlier. It's worth revisiting the planned flight mission, one phase at a time.

QuoteSpiral was built to allow for a powered landing and go-around maneuver in case of a missed landing approach. An air intake for a single Kolesov turbojet was mounted beneath the central vertical stabilizer. This was protected during launch and re-entry by a clamshell door which opened at subsonic speeds. By comparison, Dyna-Soar was designed primarily for a once-off, unpowered deadstick landing.

A small detail that called my attention. The craft was capable of powered descent (final approach). A single small turbojet placed on the leeside next to the vertical stabilizer.  Normally from an aerodynamic perspective, one would avoid that location due to turbulence and the possibly a fully separated turbulent boundary layer creating havoc with the airflow to the rear engine.  Yet the need to protect the engine during re-entry overrides that decision....

Airlander continues to make progress towards flight - http://www.themanufacturer.com/articles/milestone-for-airlanders-return-to-flight-scheme/ (http://www.themanufacturer.com/articles/milestone-for-airlanders-return-to-flight-scheme/).

Yours,
Miranda.

Quote from: Miranda.T on February 22, 2016, 06:14:31 PM
Airlander continues to make progress towards flight - http://www.themanufacturer.com/articles/milestone-for-airlanders-return-to-flight-scheme/ (http://www.themanufacturer.com/articles/milestone-for-airlanders-return-to-flight-scheme/).

Yours,
Miranda.

Given that form follows function, what is it about the design that calls for a bifurcated envelope? (Or, to phrase it more "rustically", why does it look like a bum?)

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Fwww.themanufacturer.com%2Fwp-content%2Fuploads%2F2016%2F01%2FThe-Airlander-Mission-Module-being-fitted.jpg&hash=fe8d8f3e8d3512a95123c1fb68a281918141bc10)

Quote from: GCCC on March 15, 2016, 05:15:11 PM

Quote from: Miranda.T on February 22, 2016, 06:14:31 PM
Airlander continues to make progress towards flight - http://www.themanufacturer.com/articles/milestone-for-airlanders-return-to-flight-scheme/ (http://www.themanufacturer.com/articles/milestone-for-airlanders-return-to-flight-scheme/).

Yours,
Miranda.

Given that form follows function, what is it about the design that calls for a bifurcated envelope? (Or, to phrase it more "rustically", why does it look like a bum?)

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Fwww.themanufacturer.com%2Fwp-content%2Fuploads%2F2016%2F01%2FThe-Airlander-Mission-Module-being-fitted.jpg&hash=fe8d8f3e8d3512a95123c1fb68a281918141bc10)

What you have there is a soft pressure vessel that provides it's own structural rigidity. Pressure vessels depend of tension around the "hoop"  to maintain their walls straight, and thus provide the rigidity required. That means that it has to at least resemble a cylinder of some sort. The "crack in the bum"  ::) actually provides a great deal of structural integrity, and allows for "hoop tension" to form along the perimeter of the envelope.  This is basic structural mechanics.

Now at the same time, modern airship designs want to take advantage of their own shape to provide some lift. The so called lifting body concept. If you looks at rival designs, some envelopes do not have the crack, or have an outer envelope covering the crack  ::)  :-X

The oval shape is to provide the maximum lifting surface possible, since the aerodynamic pressure distribution around the envelope is your only source of lift. The "split hot-dog bun" envelope, is in my mind a compromise between structural rigidity and pressure vessel requirements and aerodynamic requirements for lift.

A surprising finding for me today. I just stumbled into this article below. It happens that Aviation Week [and Space Technology] magazine is already over 100 years old this year, having first published in 1916.

http://aviationweek.com/blog/potted-history-airships (http://aviationweek.com/blog/potted-history-airships)

More pleasantly I also discovered that some of the first articles in that magazine were also discussing a "revival" of lighter than aircraft, and made cavalier forecasts of lighter than air aeronautical developments in Europe and the United States.

The article follows up various AW articles that were printed throughout the 20th C, including a 1929 article on the The British State Airship R101, The 1937 Hindenburg tragedy, a 1959 article of the deployment of the first Goodyear airborne early warning airships, and a 2010 article on the Northrop Grumman long endurance multi-intelligence vehicle (LEMV).

Nice little resource. I plan on fetching all the articles, and I may decide to post here or in the histopriacal section with a link....

Quote
A journalist predicted in the February 1, 1917 issue of Aviation Week, that great progress would be made in developments of lighter-than-air craft in the U.S., and similar predictions for Europe were foretold.

All types of lighter-than-air aircraft would be designed and built by one company, the Connecticut Aircraft Co. Its qualification? It recently received an order from the Signal Corp for an observation balloon.

It had a capacity of 30,000 cubic feet of hydrogen. The main gas bag was built of double textured rubberized cotton, cemented and sewn together

So this is the third approach, from Jeff Bezo's Blue Origin, which I have seen besides Space X's and Sierra Nevada Corp's attempts at re-usable manned launch systems.

Blue Origin's approach is similar to Space X's "retro-rocket" booster design, but the intersting here is how the design reveals the design struggle withing the engineering teams.

The project calls for a re-usable rocket booster which will kand under it's own power after a brief suborbital flight (i.e. up and down").  The booster is carrying a manned capsule, in this case to a maximum altitude of 104 km the "lowest" threshold of space, as it were.  

But the interesting thing is that the booster and the capsule separate (I'm not exacly sure when), and then as the booster is a mere 3600 ft above ground it re-fires to very suddenly decelerate it's path toward the Earth.  The launch site near the town of Van Horn in Western Texas is at about 4000 ft above sea level (yes Texas has mountains and high plateaus!), so this means the rocket is re-ignited around 7600 ft of altitude above sea level. To put it in context, the altitude of Denver is 5280ft  and Mexico City is around 7380 ft of altitude above the ocean.

The result is a rocket devoid of capsule which approaches the ground very, very fast and at the very last moment, it suddenly slows to a very slow soft landing a 4.8 mph.  The video is really impressive, if indeed the video playback I'm looking at is in real-time. This also explains why you can't land with the capsule attached! Imagine you are at the tip of the rocket in the last few seconds before touchdown...

Flight Three: Pushing the Envelope (http://www.youtube.com/watch?v=YU3J-jKb75g#)

https://www.blueorigin.com/ (https://www.blueorigin.com/)

The Storm (Буря) (an frticle of "350"-350 La-350, La-X) — the world's first supersonic two-stage Intercontinental cruise missile land-based, developed in the mid 1950-ies in the USSR in the OKB-301 Lavochkin under the leadership of S. A.

In 1954 the Council of Ministers of the USSR adopted a decision to establish an unmanned Intercontinental means of delivery of nuclear warheads with ranges of at least 8,000 km. That decision provided for the research and design work in parallel in two competing directions: Intercontinental ballistic missiles (ICBMs), and Intercontinental cruise missiles (MD).

Rocket "Storm" was the implementation of the second direction, the contractor which was assigned to the OKB-301 (now "NPO im. S. A. Lavochkin"), and chief designer — N. S. Chernyakov.

The propulsion system (rocket engine) first stage has been developed in OKB-2, under the leadership of chief designer A. M. Isayev.

Ramjet engine the primary stage was designed at OKB-670 under the leadership of M. M. Bondaryuk.

The design of the rocket was designed to fly on Intercontinental range (up to 8 000 km), at altitudes up to 25 km, with marches 3.2 speed—Mach 3.3, with the implementation of the anti-aircraft maneuvers in a given time moment. The starting weight of the rocket 95 t, weight of a martial step 33 tons, the weight of the payload (warhead) of 2.35 T.

During the development of the rocket "the Tempest" for the first time in USSR was mastered a number of technical and technological innovations:

• supersonic ramjet engine (SPVRD);
• astronavigational the automatic flight control system;
• machining and welding titanium alloys.

Layout — two-stage rocket with a longitudinal separation steps.
The first stage (accelerator) — block 2 missile with rocket engines.
The second (sustainer) stage cruise missile with ramjet engine.

Under the flight program rocket engines on the first stage starts with the launcher vertically, gradually turns in horizontal flight and at a height of 17,500 m accelerates to speed M≈3, when you turn on the engine of a martial step, and the steps. Further cruise missile goes to the target at a height of 17÷18 km commands astronavigational management system, at the approach to the goal of gaining a height of 25 km (anti-aircraft maneuver), and dive-bombing target. Flight to maximum range together with the rise and dispersal lasts about 2.5 hours.

All were built 19 year old copies of "Storm" (factory № 18 in Kuibyshev and plant No. 301 in Moscow), and they were tested. The last four missiles are used in order to create the optical reconnaissance and target for anti-aircraft missile defense complex long-range "Distance," developed by OKB-301. The outbreak was the preparation of serial
production of the CD was cancelled. The story of "Storm" has ended .

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Fcdn.topwar.ru%2Fuploads%2Fposts%2F2013-12%2F1387163177_mewss.jpg&hash=cb58584e83cf08b659fe72199ca2b8ae9d117cfe) (https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Fcdn.topwar.ru%2Fuploads%2Fposts%2F2013-12%2F1387163292_burya1.jpg&hash=f5609c104fe4783c1b7d935ef0b1a07e0490dfad)

Испытания крылатой ракеты "БУРЯ" (http://www.youtube.com/watch?time_continue=753&v=yP0FGbTe3LE#)

Lavochkin La-350 'Burya' prototype intercontinental cruise missile (http://www.youtube.com/watch?v=po2BPfbfKCc#)

late to the show, as usual. I have no filght techno-skills, just a compuer jocky that got
hired in to do "systems" then bailed out ca. 1990.

RE The Shuttle:

as a prior participant (just a small cog I assure you), I have a few comments:

The O-Ring crap is/was a smoke-screen, here was no actual proof, only conjecture. They needed a sacrificial goat, fast,
and decided upon MT o-rings. An independent assesment by ex-players published in Aviation Week & Space Technology
recommended that investigators look into
1) the "drilling of extra holes" along the joining flanges of solid propellant boosters (thus weakening the joints)
2) the photos clearly showing a forward mounting strut from the shuttle to the fuel tanks breaking loose
and perforating the liquid fuel tank, and the resulting jet of liquid fuel

http://www.nytimes.com/1986/02/11/us/puncture-of-large-fuel-tank-by-pivoting-booster-is-cited.html (http://www.nytimes.com/1986/02/11/us/puncture-of-large-fuel-tank-by-pivoting-booster-is-cited.html)

But it was squashed.

The Shuttle was a good design, especailly for the day. A bit overly large. Nasa wanted a pick-up truck, and the
Pentagon demanded a Semi-Truck and got it. Actaully it was a "pretty damn good design" with all the different
contactors not playing nice together- so damn good the Soviets were copying it until their economy crashed.

The shuttle was good for what it was, and it should have been a stepping stone, to a better system and permanent
stations built at the LaGrange points. The Shuttle program WAS NOT READY for civilian scientist ride-alongs,
but the public image being projected demanded it. But the budgets were cut to the bone, cheap-a$$ bean-counters
were put in charge, and the KB's (kabooms) happened as a direct result. That doomed it all. To the bean-counters,
budget mattered more than lives.

If you don't agree, read the transcripts where the astronauts were directly forbidden from looking for any tile
damage. Lawyers call that culpable deniabilty.

BTW, in "the biz" everything was so compartmentalized, we never knew wtf we were working on, so we went to
Avionics Week, found out who was flying where for what, and figured it out. Their photos were the only way we ever saw
the platforms fly.

ooohhhh   "Sierra Nevada Corporation's Dream Chaser mini-shuttle" <<<< --- that should have been the next step!

perhaps it will, yet...

I am intrigued that no-one is pursuing rail-launch from an Andes Mountain in order to avoid the dreaded "muti-stage rockets" .

yhs
prof (been yelled at by generals)  marvel

Quote from: morozow on April 20, 2016, 03:32:38 PM
The Storm (Буря) (an frticle of "350"-350 La-350, La-X) — the world's first supersonic two-stage Intercontinental cruise missile land-based, developed in the mid 1950-ies in the USSR in the OKB-301 Lavochkin under the leadership of S. A.

(snip)

Want one! Want one!*

You can't help but be impressed by some of the innovative Soviet/Russian designs, especially in the area of aerospace; for example, I do think if Korolev hadn't died it would have been a very close run race to the moon.

Quote from: Prof Marvel on April 26, 2016, 06:22:54 AM
late to the show, as usual. I have no filght techno-skills, just a compuer jocky that got
hired in to do "systems" then bailed out ca. 1990.

RE The Shuttle:

as a prior participant (just a small cog I assure you), I have a few comments:

(snip)

Impressive to (virtually) meet someone involved in that programme! I hadn't heard the strut theory for that disaster. But yes, it was the lack of dollars that compromised that programme. If they had just stuck with the original design with a winged first stage things might have been different (although those tiles were always going to be its Achilles heel). Of course, it's recently been announced that AFRL are looking again at a two stage to orbit vehicle with presumably a winged first stage using the SABRE engine  http://www.space.com/32115-skylon-space-plane-engines-air-force-vehicle.html#sthash.YfkJHzdV.ANlzVOmt.dpuf (http://www.space.com/32115-skylon-space-plane-engines-air-force-vehicle.html#sthash.YfkJHzdV.ANlzVOmt.dpuf).

Yours,
Miranda.

*At the recent Malvern Flea Market there was a RR jet engine for sale, £1500 including delivery. The family wouldn't let me buy it...

All of us here knew we were on the right track... http://www.telegraph.co.uk/science/2016/04/09/steam-powered-spacecraft-could-help-humans-colonise-the-moon/ (http://www.telegraph.co.uk/science/2016/04/09/steam-powered-spacecraft-could-help-humans-colonise-the-moon/).

Yours,
Miranda.

Quote from: Miranda.T on April 26, 2016, 06:47:57 PM

Quote from: morozow on April 20, 2016, 03:32:38 PM
The Storm (Буря) (an frticle of "350"-350 La-350, La-X) — the world's first supersonic two-stage Intercontinental cruise missile land-based, developed in the mid 1950-ies in the USSR in the OKB-301 Lavochkin under the leadership of S. A.

(snip)

Want one! Want one!*

You can't help but be impressed by some of the innovative Soviet/Russian designs, especially in the area of aerospace; for example, I do think if Korolev hadn't died it would have been a very close run race to the moon.

Quote from: Prof Marvel on April 26, 2016, 06:22:54 AM
late to the show, as usual. I have no filght techno-skills, just a compuer jocky that got
hired in to do "systems" then bailed out ca. 1990.

RE The Shuttle:

as a prior participant (just a small cog I assure you), I have a few comments:

(snip)

Impressive to (virtually) meet someone involved in that programme! I hadn't heard the strut theory for that disaster. But yes, it was the lack of dollars that compromised that programme. If they had just stuck with the original design with a winged first stage things might have been different (although those tiles were always going to be its Achilles heel). Of course, it's recently been announced that AFRL are looking again at a two stage to orbit vehicle with presumably a winged first stage using the SABRE engine  http://www.space.com/32115-skylon-space-plane-engines-air-force-vehicle.html#sthash.YfkJHzdV.ANlzVOmt.dpuf (http://www.space.com/32115-skylon-space-plane-engines-air-force-vehicle.html#sthash.YfkJHzdV.ANlzVOmt.dpuf).

Yours,
Miranda.

*At the recent Malvern Flea Market there was a RR jet engine for sale, £1500 including delivery. The family wouldn't let me buy it...

Makes me want to dust-off my links to the Govmt's. job application website. I used to apply often but I wonder what the availability is if any, and whether my now outdated and meager software knowledge will be an obstacle. The AFRL and the AFOSR were the entities who gave us contracts at our university. 

I'm glad they're looking at the SABRE again, but they're repeating, basically the work done by Reaction Engines. "With lead feet," is what I would characterize the approach. The American AF people will test the engine concept all over again before committing to anything.  In that sense, it'd be so much better if a private company like Space X or Sierra Nevada had taken up the challenge. The process would be much faster.

On the other hand, despite my financial problems, I'm not at odds with the Federal Govt. So there is no obstacle at filing aoplications. Generally the big obstacle is they want a PhD and/or experience. And the longer they take to repeat the SABRE performance, the more people they're likely to hire...

Time to take a look at USAJOBS.com again.

Quote from: J. Wilhelm on April 28, 2016, 01:51:08 AM

Makes me want to dust-off my links to the Govmt's. job application website. ....

On the other hand, despite my financial problems, I'm not at odds with the Federal Govt. So there is no obstacle at filing aoplications. Generally the big obstacle is they want a PhD and/or experience. And the longer they take to repeat the SABRE performance, the more people they're likely to hire...

Time to take a look at USAJOBS.com again.

Go for it J!

Remove the dates from your degrees and papers, then the resume will get past the HR morons scrutiny and stand a chance to get in the hands of the hiring managers. If you can make some contacts with the local acedemics, that could be a plus. Shoot , maybe you could talk your way into a spot at the U ?

yhs

Quote from: Prof Marvel on April 29, 2016, 02:55:07 AM

Quote from: J. Wilhelm on April 28, 2016, 01:51:08 AM

Makes me want to dust-off my links to the Govmt's. job application website. ....

On the other hand, despite my financial problems, I'm not at odds with the Federal Govt. So there is no obstacle at filing aoplications. Generally the big obstacle is they want a PhD and/or experience. And the longer they take to repeat the SABRE performance, the more people they're likely to hire...

Time to take a look at USAJOBS.com again.

Go for it J!

Remove the dates from your degrees and papers, then the resume will get past the HR morons scrutiny and stand a chance to get in the hands of the hiring managers. If you can make some contacts with the local acedemics, that could be a plus. Shoot , maybe you could talk your way into a spot at the U ?

yhs

Yeah. I'm afraid I will have to erase the dates. The mid 2000s no longer look like a fresh date. Don't like to omit information, but that is also what I had to do to get my current job (That is greatly downgrade my business experience!! Who would have thought that "less is more"?  ??? ).

The hiring people are a bunch of f&*^%$.  They really are full of misconceptions, prejudices and downright superstition when it comes to choosing people to interview. Sometimes I get the impression that a computer running a virtual Ouija board actually determines the interview candidates.  Either that, or the "money under the table" system is in full-effect, but nobody wants to believe that would happen....

To be honest with you, the university has always been my default go-to place, due to the simple fact that that is the one place I can actually go talk with human beings *before* the interview. I have gotten in the past the most promising interviews on campus. But sadly, I have have found former professors and faculty members themselves to be less than helpful - if perhaps sympathetic to my situation.  In fact I get to see one of my graduate advisors on a weekly basis at my place of employment. But I don't want sympathy, because I can't eat that.  :-\ 

My impression is that at least some of the the faculty members "live in their own little world." What I need is faculty members not involved with internal student research but rather with external contracts. Private industry contracts may be more productive, as small companies are moree willing to take risks. There used to be a lot more of that in the late 1990s, but for Aerospace contracts tended to be with the military (Air Force, sometimes Navy), whereas the Mechanical Engineering Dept. would have more contracts with large private companies such as General Motors.

The other approach is to try to get an on-campus job doing anything -at all. That opens the list of jobs because some applications are restricted to university students and personnel. If I had a better paying job that afforded me more free time, maybe I'd go back an train myself in something else, just to get my foot back in the door.

The other approach is to try to get "through the back door," as the govt. works with many subcontractors. A small research company - I thought - would always be ideal - or so I thought. This was my approach back in 2009-10. When aerospace contracts went down I was looking for GPS related work at labs in local colleges (systems for monitoring alignment of rocket sled rails in the desert), and then the Navy started hiring computer programmers and acoustic specialists - all along the East Coast, in Virginia and surroundings. I tried unsuccessfully to get through those types endeavors, by way of research laboratories - because they wanted programmers skilled in old defunct structured languages, such as Fortran  :o

A more crazy idea: a customer at my workplace suggested I try getting in through the airline industry, as there is always some corporate liaison who has to deal with airplane makers.

Sometimes it looks so daunting. It's very difficult not to get depressed. I'm tired of counting years.

In the news right now: the Airlander 10 has been unveiled at Cardington Airfield, Bedfordshire, and christened the "Martha Gwyn." The joined dual-envelope lifting body design makes this an "airship-airplane hybrid."

BBC:

QuoteBritish firm Hybrid Air Vehicles (HAV) has spent the past nine years developing the prototype in the Cardington hangar after the US Army ran out of money to develop it as a surveillance machine.

Tests on its engines, generators and systems were completed last week, and tests on ground systems will now be carried out outside of the hangar.

Read more about it:

http://www.bbc.com/news/uk-england-beds-bucks-herts-36997711 (http://www.bbc.com/news/uk-england-beds-bucks-herts-36997711)

US Army cancellation of LEMV
http://newatlas.com/lemv-airship-canceled/26274/ (http://newatlas.com/lemv-airship-canceled/26274/)

LEMV first flight
LEMV First Flight (http://www.youtube.com/watch?v=R1G-L7qvTKI#)

Hybrid Air Vehicle's (UK) takeover of the project
https://en.wikipedia.org/wiki/Hybrid_Air_Vehicles_HAV_304_Airlander_10 (https://en.wikipedia.org/wiki/Hybrid_Air_Vehicles_HAV_304_Airlander_10)
https://en.wikipedia.org/wiki/Hybrid_Air_Vehicles (https://en.wikipedia.org/wiki/Hybrid_Air_Vehicles)

World's largest airplane, the Airlander 10, prepares to take maiden flight in UK - TomoNews (http://www.youtube.com/watch?v=Q0Zve5GJ-80#)

1898. Balloon "Andrew Pihlstrom in flight

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Fic.pics.livejournal.com%2Fmi3ch%2F983718%2F7528025%2F7528025_original.jpg&hash=91be5dab1476ccd48c9d732b51f745b19ecc428c)


1910. Start of the airplane "Farman" at Kolomyazhsky racetrack

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Fic.pics.livejournal.com%2Fmi3ch%2F983718%2F7531775%2F7531775_original.jpg&hash=b2a343291f3a7c1914dd48340e515d596888dfae)

1933. Start spy plane KR-1 from the battleship "Paris commune"

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Fic.pics.livejournal.com%2Fmi3ch%2F983718%2F7530571%2F7530571_original.jpg&hash=e942ec35681d06ddfede0630698e2ce0aaf16369)

I guess lately I haven't been playing much attention to new aerospace developments.  I was reading the BBC's articles on India's latest launch of multiple satellites in a single vehicle

India's latest multiple satellite launch

http://www.bbc.com/news/world-asia-india-37448629 (http://www.bbc.com/news/world-asia-india-37448629)


and I noticed that their "Swadeshi" "mini space shuttle"  proof of concept had been launched in May.


RLV-TD (http://www.youtube.com/watch?v=_2YIvYa7oOY#)

The Reusable Launch Vehicle Technology Demonstration Programme (RLV-TD) not only develops a  proof of concept re-entry hypersonic glider but the  project will also help develop a SCRAMJET powered air-breathing rocket:

India's Space Shuttle experimental vehicle

http://www.bbc.com/news/world-asia-india-36355842 (http://www.bbc.com/news/world-asia-india-36355842)

https://en.wikipedia.org/wiki/RLV-TD (https://en.wikipedia.org/wiki/RLV-TD)

Quote from: J. Wilhelm on September 26, 2016, 07:24:26 AM
I guess lately I haven't been playing much attention to new aerospace developments.  I was reading the BBC's articles on India's latest launch of multiple satellites in a single vehicle

Ah My Dear J -
being a suspicious sort I have to wonder, how often does one want to send up satellites in similar, nearby, or the same orbit?
thus leading me to wonder if it is a poorly disguised development of MIRV tech...

love the small shuttle, tho :-)

yhs
prof ( wondering) marvel

Quote from: Prof Marvel on October 03, 2016, 04:31:35 AM

Quote from: J. Wilhelm on September 26, 2016, 07:24:26 AM
I guess lately I haven't been playing much attention to new aerospace developments.  I was reading the BBC's articles on India's latest launch of multiple satellites in a single vehicle

Ah My Dear J -
being a suspicious sort I have to wonder, how often does one want to send up satellites in similar, nearby, or the same orbit?
thus leading me to wonder if it is a poorly disguised development of MIRV tech...

love the small shuttle, tho :-)

yhs
prof ( wondering) marvel

Yeah. It's all related isn't it? I can't seem to get away from that . Military leads to commercials and viceversa. Well, I don't know the particulars of their system (since I just read about it through the news last week), but theirs is not the only system like that. I imagine the last stahe boosts to a higher orbit than MIRV's, and there are hypergolic or otherwise types of rockets that will reduce each individual payload's orbit in order to space the satellites apart (I'm guessing here, I'm not an Orbital Mechanics guy).

Here in our ow hometown of Austin we have a new company called Firefly (yes I have applied for a job - with negative response), started by a former associate of Elon Musk at SpaceX. Their speciality *will* be multiple (micro) satellite launch systems modelled after multiple warhead missiles.

~ ~ ~

My mind had been occupied as of late as I applied for and got an interview for an internship with a small division of a very large company (Flight Safety Intl.) which trains pilots. The Austin offices are part of an engineering division which makes mirrors for flight the flight simulators they make (my interview resulted in a somewhat yet not definitively negative response). Even giving my work for free I get rejected  :-\ in this case, on account I'm not an expert in optics and materials science. I estimate I have only one more shot at this job if I could just find a way to marry CAD / vector drafting software to an optics program called Zemax (so they can estimate optical aberrations in real time just by changing mirror positions). Also I need to find a substitute for glass which is lighter but can be polished like glass...

I hear Mr. Brassbeard may know something about 3D modelling? I wonder if that could be helpful?

October 4 1957 was launched into orbit the first artificial Earth satellite, the Soviet spacecraft - Sputnik-1.

(https://upload.wikimedia.org/wikipedia/commons/b/be/Sputnik_asm.jpg)

Quote from: morozow on October 04, 2016, 02:58:29 PM
October 4 1957 was launched into orbit the first artificial Earth satellite, the Soviet spacecraft - Sputnik-1.

(https://upload.wikimedia.org/wikipedia/commons/b/be/Sputnik_asm.jpg)

Of course - 60th anniversary next year. It's amazing just how far we have come since then, from the first artificial satellite to contemplating the first interstellar mission ('Breakthrough Starshot'). Anyway, there really should be some short of global commemoration of the 60th next year.

Yours,
Miranda.

Yesterday, Pilot, Engineer, Astronaut and Senator John H Glenn, has passed away after health complications. He was the third man to orbit Earth after Yuri Gagarin and Gherman Titov, and the 4th man to go into space after Alan Shepard and Gus Grissom's suborbital flights

I have written an obituary at the Off Topic section, and I will probably write something in this thread about early space exploration and the Mercury Programme in the next few days.

For the obituary, follow this link: http://brassgoggles.co.uk/forum/index.php/topic,48530.msg977319.html (http://brassgoggles.co.uk/forum/index.php/topic,48530.msg977319.html)

Alright, this is really interesting. One of the biggest problems in space exploration is the ridiculous amount of garbage that humanity has launched to low Earth orbit and even up to geostationary orbit, much further away from the Earth's surface.
The Japanese have come up with and are now beginning to test a sort of orbital garbage sweeper

I'm just starting to read on the subject, but I had dreamed many times of tackling this very issue.  The problem is that speeds necessary to stay in orbit close to Earth are very high and even if most objects are orbiting more or less along the Equator in the same direction as the rotation of Earth, you still have orbits that are not perfectly circular or are at a significant angle with respect to the Equator. This means that the differential of speed between two objects could be many thousands of miles per hour, up to 5 digits for polar orbits intersecting equatorial orbits. At those speeds even the smallest most innocent objects become lethal projectiles.

So the question is how to deal with a gigantic cloud of deadly debris around the world. Not an easy issue to take because most orbiting garbage is undetectable. The United States Air Force keeps track of the most detectable objects in low Earth orbit but removing those objects is a completely different matter.

In this article below the BBC presents a description of Japan's latest bid to deal with the problem: an orbiting tether which will slow down objects enough so they can descend into the atmosphere and let aerodynamic drag slow them down out of orbit into a fiery death...

http://www.bbc.com/news/world-asia-38265676 (http://www.bbc.com/news/world-asia-38265676)

Quote from: J. Wilhelm on December 10, 2016, 02:18:17 AM
Alright, this is really interesting. One of the biggest problems in space exploration is the ridiculous amount of garbage that humanity has launched to low Earth orbit and even up to geostationary orbit, much further away from the Earth's surface.
The Japanese have come up with and are now beginning to test a sort of orbital garbage sweeper

I'm just starting to read on the subject, but I had dreamed many times of tackling this very issue.  The problem is that speeds necessary to stay in orbit close to Earth are very high and even if most objects are orbiting more or less along the Equator in the same direction as the rotation of Earth, you still have orbits that are not perfectly circular or are at a significant angle with respect to the Equator. This means that the differential of speed between two objects could be many thousands of miles per hour, up to 5 digits for polar orbits intersecting equatorial orbits. At those speeds even the smallest most innocent objects become lethal projectiles.

So the question is how to deal with a gigantic cloud of deadly debris around the world. Not an easy issue to take because most orbiting garbage is undetectable. The United States Air Force keeps track of the most detectable objects in low Earth orbit but removing those objects is a completely different matter.

In this article below the BBC presents a description of Japan's latest bid to deal with the problem: an orbiting tether which will slow down objects enough so they can descend into the atmosphere and let aerodynamic drag slow them down out of orbit into a fiery death...

http://www.bbc.com/news/world-asia-38265676 (http://www.bbc.com/news/world-asia-38265676)

The ESA are planning some experimental missions to the same end, using ideas such as capturing errant satellites using harpoons and nets. The real problem is, as you have identified, the small pieces like nuts and fragments of metal, but which still have enough kinetic energy to punch a hole through a spacecraft's side.

Yours,
Miranda.

If only we had an aether wave grappler beam to pull passing debris out of orbit.

The airplane "Farman-IV", built according to the drawings 1910

Odessa

Аэроклуб "Одесса". Первый полёт Одесского "Farman IV" (http://www.youtube.com/watch?v=8VYQWJkV0Mw#)

Quote from: Peter Brassbeard on December 12, 2016, 04:16:11 PM
If only we had an aether wave grappler beam to pull passing debris out of orbit.

Well, if the 21st century name for an "aether wave grappler beam" is a laser, then that might just be possible - have a look towards the end of this article http://www.space.com/35008-comet-strike-danger-to-earth.html (http://www.space.com/35008-comet-strike-danger-to-earth.html).

Yours,
Miranda.

Quote from: Miranda.T on December 15, 2016, 11:35:57 PM

Quote from: Peter Brassbeard on December 12, 2016, 04:16:11 PM
If only we had an aether wave grappler beam to pull passing debris out of orbit.

Well, if the 21st century name for an "aether wave grappler beam" is a laser, then that might just be possible - have a look towards the end of this article http://www.space.com/35008-comet-strike-danger-to-earth.html (http://www.space.com/35008-comet-strike-danger-to-earth.html).

Yours,
Miranda.

Rather than a grapple, this would be a deflector beam. The idea of using a laser for comets makes sense when you consider that blasting energy to icy bodies can result in jets of vapour or gases acting as thrusters on the comet, deviating its orbit.

Other than that, barring any jets, a body that needs to be deflected would presumably need to receive enough momentum from the colliding photos to actually deviate it's orbit.

I have heard of long term exposure to laser radiation which can over time significantly alter the orbit of an object, or propel an object through space. Generally speaking, the photon pressure is extremely low, but in the relative vacuum of space, and over long periods of time, the idea is the basis for probes or spaceships that could be accelerated to very high speeds, some significant percentage (say 25% of the speed of light). So it's possible that you could focus a laser long enough on a satellite to knock it's orbit.  Buf off the top of my head I don't know how much pressure you can get from say a very intense burst or set of bursts of a laser beam. 

Among some job applications for jobs involving secret government-sponsored research programmes, I have heard of projects which aim to concentrate ridiculously large amounts of energy in an extremely short duration laser pulse (directed energy weapons based on power amplification), which could actually vaporize, melt or otherwise push larger objects. But I need to do some calculations to see what is realistic or not (I'm definitely not an expert in the subject, so I'd have to re-invent the wheel and rely on my generalized knowledge starting from first principles)

Quote from: J. Wilhelm on December 16, 2016, 05:42:10 AM

Quote from: Miranda.T on December 15, 2016, 11:35:57 PM

Quote from: Peter Brassbeard on December 12, 2016, 04:16:11 PM
If only we had an aether wave grappler beam to pull passing debris out of orbit.

Well, if the 21st century name for an "aether wave grappler beam" is a laser, then that might just be possible - have a look towards the end of this article http://www.space.com/35008-comet-strike-danger-to-earth.html (http://www.space.com/35008-comet-strike-danger-to-earth.html).

Yours,
Miranda.

Rather than a grapple, this would be a deflector beam. The idea of using a laser for comets makes sense when you consider that blasting energy to icy bodies can result in jets of vapour or gases acting as thrusters on the comet, deviating its orbit.

Other than that, barring any jets, a body that needs to be deflected would presumably need to receive enough momentum from the colliding photos to actually deviate it's orbit.

I have heard of long term exposure to laser radiation which can over time significantly alter the orbit of an object, or propel an object through space. Generally speaking, the photon pressure is extremely low, but in the relative vacuum of space, and over long periods of time, the idea is the basis for probes or spaceships that could be accelerated to very high speeds, some significant percentage (say 25% of the speed of light). So it's possible that you could focus a laser long enough on a satellite to knock it's orbit.  Buf off the top of my head I don't know how much pressure you can get from say a very intense burst or set of bursts of a laser beam. 

Among some job applications for jobs involving secret government-sponsored research programmes, I have heard of projects which aim to concentrate ridiculously large amounts of energy in an extremely short duration laser pulse (directed energy weapons based on power amplification), which could actually vaporize, melt or otherwise push larger objects. But I need to do some calculations to see what is realistic or not (I'm definitely not an expert in the subject, so I'd have to re-invent the wheel and rely on my generalized knowledge starting from first principles)

The article did talk about using the laser to de-orbit space debris. I'd imagine the idea would be to heat one side of the debris causing vaporisation of material, the reaction force from this altering the orbit to one which, at some point in its cycle, grazes through the upper atmosphere. Then let friction do the rest.

Yours,
Miranda.

Happy New Year! Let's hope I get a new stab at relevant jobs this year. I'm continuing my efforts to get an internship in smaller Aerospace outfits as a way to upgrade my underemployment situation...

An interesting development. Two researhers at Harvard claim to have produced a droplet of metallic hydrogen. A drop of hydrogen is squeezed in an anvil made of two diamonds, until the pressure reaches 495 GPa. At that point the droplet transitions from an ice-like transparent solid to a black semiconductor, and finally into a solid metal. If correct, there are serious implications; it had been predicted many decades ago that metallic hydrogen not only is a superconductor but is metastable, that is, if you bring it back to lower pressures it would stay in metallic form.

The applications range from superconductive cables through to rocket propellants with an incredibly high specific impulse.

http://www.bbc.com/news/science-environment-38768683 (http://www.bbc.com/news/science-environment-38768683)

Motors with metallic hydrogen superconducting windings ... Truly wicked self destruct mode thrown in for free.

Reading over on The Deco Lounge about jet powere seaplanes and as a result of this may I present... a proposed nuclear powered seaplane  :o

Have a look at http://www.google.co.uk/url?q=http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2010_06_03_SR_Princess.pdf&sa=U&ved=0ahUKEwjzkdSXpIvSAhUBxRQKHU1VB1cQFggyMAg&usg=AFQjCNGkm9O0ouQ-I60-dOmZirYxHceg9g (http://www.google.co.uk/url?q=http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2010_06_03_SR_Princess.pdf&sa=U&ved=0ahUKEwjzkdSXpIvSAhUBxRQKHU1VB1cQFggyMAg&usg=AFQjCNGkm9O0ouQ-I60-dOmZirYxHceg9g), slide 187.

Yours,
Miranda.

P.S. If interested you do a search and find a web-site with more information on this, but it seemed a bit militaristic so I hesitated to post a direct link here.

Quote from: Miranda.T on February 12, 2017, 07:58:46 PM
Reading over on The Deco Lounge about jet powere seaplanes and as a result of this may I present... a proposed nuclear powered seaplane  :o

Have a look at http://www.google.co.uk/url?q=http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2010_06_03_SR_Princess.pdf&sa=U&ved=0ahUKEwjzkdSXpIvSAhUBxRQKHU1VB1cQFggyMAg&usg=AFQjCNGkm9O0ouQ-I60-dOmZirYxHceg9g (http://www.google.co.uk/url?q=http://www.fzt.haw-hamburg.de/pers/Scholz/dglr/hh/text_2010_06_03_SR_Princess.pdf&sa=U&ved=0ahUKEwjzkdSXpIvSAhUBxRQKHU1VB1cQFggyMAg&usg=AFQjCNGkm9O0ouQ-I60-dOmZirYxHceg9g), slide 187.

Yours,
Miranda.

P.S. If interested you do a search and find a web-site with more information on this, but it seemed a bit militaristic so I hesitated to post a direct link here.

I don't know of you were here back then but about 3 year ago I was talking to a friend about re-sizing (aircraft design) an existing boat plane, because most modern versions are too small, have a very short range, and he needed it to visit a tiny chunk of atoll "land" he owns in the middle of the Pacific. The biggest problem besides extending the range (longer wing span, external tanks), was allowing for a single or two crew plane to operate over what is regarded to be the safe shift of 8 hours including issues like bathroom breaks.

It never occurred to me to suggest a jet powered seaplane

https://en.m.wikipedia.org/wiki/Martin_P6M_SeaMaster (https://en.m.wikipedia.org/wiki/Martin_P6M_SeaMaster)

A real pipe dream to make a larger nuclear version of it, but it seems a new era of flying boats could happen in some alternate universe.

Today India launched a rocket with the largest number of satellites ever to comprise a payload. An Indian rocket carrying 104 small satellites has surpassed the previous record of 37 satellites launched in a single mission by Russia two years ago.

http://www.bbc.com/news/world-asia-india-38977803 (http://www.bbc.com/news/world-asia-india-38977803)

https://twitter.com/business/status/831717427314438144 (https://twitter.com/business/status/831717427314438144)

Of the 104 small satellites, 96 belong to the United States while Israel, Kazakhstan, the United Arab Emirates, Switzerland and the Netherlands are the other foreign clients.

An Indian cartographic satellite, believed to be capable of taking high resolution images is also on board. It is expected to be used to monitor regional arch rivals Pakistan and China.

Quote from: J. Wilhelm on February 15, 2017, 05:17:45 AM
Today India launched a rocket with the largest number of satellites ever to comprise a payload. An Indian rocket carrying 104 small satellites has surpassed the previous record of 37 satellites launched in a single mission by Russia two years ago.
.....
Of the 104 small satellites, 96 belong to the United States while Israel, Kazakhstan, the United Arab Emirates, Switzerland and the Netherlands are the other foreign clients.

An Indian cartographic satellite, believed to be capable of taking high resolution images is also on board. It is expected to be used to monitor regional arch rivals Pakistan and China.

Yes My Dear J ,
Whilst I applaud the achievements of others, I fear the U.S. is now little more than a consumer of other nations' goods, services, and a purchaser of others' technological advancements .

I fear the US is follwing the appocryphal predictions of the movie "Idiocracy".

If the current trends continue ( ie: beer, sports, pizza, bread and circuses "trumping" scientific and aerospace advancements and quality health care )  we may be looking for a different place to live....

your sad servant
prof mumbles.

The best way to find out where we are and what we are doing wrong is for us to look closely and  without prejudice at those nations we traditionally deem as "inferior." Most people in the First World would be amazed at what some people have accomplished with much less money. We could learn a thing or two from them and perhaps realize that we are not as superior as we think we are, and God willing we may even see where we went wrong.

Our biggest enemies are our own prejudice and ignorance. Which is perhaps, why every American should travel abroad and experience the world (following the advice of Mark Twain).

Looks like SpaceX 's booster rockets are now returning and landing safely on the ground. SpaceX just launched a supply ship bound to the international space station.


http://www.bbc.com/news/science-environment-39021729 (http://www.bbc.com/news/science-environment-39021729)

This video also caught my eye :

http://www.bbc.com/news/technology-39003397 (http://www.bbc.com/news/technology-39003397)

Single passenger pilot-less drone will serve as a "sky taxi" in Dubai starting this year, according to the BBC.

The drone is electric, has a single occupant cabin, capable of carrying a 100kg passenger, and enough batteries for 8 rotors.

It's exiting to see that. Makes me want to re-visit my 4 tilt rotor jet liner,  Project Zarquon. Seems to me that 4 rotor geometries seem to be more stable. Naturally a tilt rotor transition is much more difficult. But makes me wonder if fuel electric hybrid motors could be the answer. To solving my problem which basically was the engines being the right size for takeoff, but greatly overpowered during cruise, not to mention the dead weight they'd be if I'd shut them down during cruise.

Perhaps electric rotor boosters would be useful for takeoff and transition flight stability. Mayhaps consider hidden electric rotors in a canard configuration aircraft.

It will not meet international safety standards, however. Certainly will not meet American FAR 29 regulations for rotor craft. My Zarquon needs to meet both FAR 35 and FAR 29 requirements which at the end made my design impractical because it needed auxiliary units just for eventualities.

SpaceX just announced a plan to send space tourists on an orbital flight around the moon by 2018!

I'll have to read further on this, but this certainly takes a bit of the fizz out of Sir Richard Branson's Virgin Galactic suborbital flights. I want to know what that primadona, Mr. Burt Rutan from Scaled Composites is going to do now to catch the competition  ;D

QuoteThe space tourists would make a loop around the Moon, skimming the lunar surface and then going well beyond, Mr Musk said. The mission will not involve a lunar landing. If Nasa decided it wanted to be first to take part in a lunar flyby mission, then the agency would have priority, Mr Musk said.

http://www.bbc.com/news/science-environment-39111030 (http://www.bbc.com/news/science-environment-39111030)

Quote from: J. Wilhelm on February 28, 2017, 03:40:20 AM
SpaceX just announced a plan to send space tourists on an orbital flight around the moon by 2018!

I'll have to read further on this, but this certainly takes a bit of the fizz out of Sir Richard Branson's Virgin Galactic suborbital flights. I want to know what that primadona, Mr. Burt Rutan from Scaled Composites is going to do now to catch the competition  ;D

I noticed that one; apparently the Dragon capsule will be tested with a NASA crew for a launch to the ISS beforehand. However, it does seem to be just one crewed flight before the circum-lunar trip - that's less than was the case for the Apollo programme, and the two people on board will be 'civilians' rather than those who piloted Apollo with their many years of preparation. They'd better not launch on the 13th...

I also noticed a story saying it's being considered, to save money, to have a crew on the first SLS flight rather than an unmanned test first. Great if it works, but if there was a disaster how far would that put back NASA's programme?

Yours,
Miranda.

Quote from: Miranda.T on February 28, 2017, 06:01:31 PM

Quote from: J. Wilhelm on February 28, 2017, 03:40:20 AM
SpaceX just announced a plan to send space tourists on an orbital flight around the moon by 2018!

I'll have to read further on this, but this certainly takes a bit of the fizz out of Sir Richard Branson's Virgin Galactic suborbital flights. I want to know what that primadona, Mr. Burt Rutan from Scaled Composites is going to do now to catch the competition  ;D

I noticed that one; apparently the Dragon capsule will be tested with a NASA crew for a launch to the ISS beforehand. However, it does seem to be just one crewed flight before the circum-lunar trip - that's less than was the case for the Apollo programme, and the two people on board will be 'civilians' rather than those who piloted Apollo with their many years of preparation. They'd better not launch on the 13th...

I also noticed a story saying it's being considered, to save money, to have a crew on the first SLS flight rather than an unmanned test first. Great if it works, but if there was a disaster how far would that put back NASA's programme?

Yours,
Miranda.

Well they did mention that NASA's personnel would have preference for a first flight. I'm surprised they'd take such a fast approach. They must have some confidence, probably due to communication with NASA. But I'd always prefer unmanned tests for each phase.  Maybe because being able to dock and manouver in orbit already counts as the equivalent of the first Apollo flights.  


What I ignore is if they will be Using a figure 8 orbit around the moon, or of they'll use a simple Hohmann transfer orbit (circle - ellipse - circle) to go to the moon. The difference is a much shorter time for a Figure 8,  and the Figure 8 requires that you burn fuel for significant part of the flight, since your are not in free fall all the time. Also the reentry speeds are higher in the figure 8 which directly impacts the design of the reentry shield (Mach 25 as opposed to Mach 20, say at the start of reentry).

Quote from: J. Wilhelm on February 28, 2017, 09:35:43 PM
(snip)

Well they did mention that Masamune personnel would have preference for a first flight. I'm surprised they'd take such a fast approach. They must have some confidence, probably due to communication with NASA. But I'd always prefer unmanned tests for each phase.  Maybe because being able to dock and manouver in orbit already counts as the equivalent of the first Apollo flights. 


What I ignore is if they will be Using a figure 8 orbit around the moon, or of they'll use a simple Hohmann transfer orbit (circle - ellipse - circle) to go to the moon. The difference is a much shorter time for a Figure 8,  and the Figure 8 requires that you burn fuel for significant part of the flight, since your are not in free fall all the time. Also the reentry speeds are higher in the figure 8 which directly impacts the design of the reentry shield (Mach 25 as opposed to Mach 20, say at the start of reentry).

It almost seems like Musk is trying to push NASA's timetable and agenda a bit. And good on him if that's the plan - forget asteroid rendezvous and prevaricating about Mars, the obvious first step out into deep space has to be the moon. It has a wealth of materials for fabrication, water to electrolyse into rocket fuel and abundant solar energy to achieve this. Establish a presence on the moon, build more ambitious missions there (i.e. Mars) and launch them from a gravity field 1/6 the strength of the Earth's. Obvious really; I'd like to say it's not rocket science, but...  :D

Musk stated today that the flight duration would be 5 days, which seems pretty much like Apollo, so I'd guess figure of eight.

Yours,
Miranda.

Well, I guess it makes sense that they'd choose that type of flight. It has been done before, and it'd be the equivalent of the Apollo 8 mission. The orbital mechanics are exactly the same, and like Apollo 8 you're still risking the life of the crew. It all comes down to the confidence in the reliability of Dragon's systems. Musk did say NASA would get first dibbs on the flight, so we may see American Astronauts go before the tourists.

With the current political climate, this is a silver lining on the black cloud, because a manned moon shot is one of America's greatest achievemens. This is a feather on the political cap of our president  ::)

I just can't believe the timing and Elon Musk's extremely cavalier chutzpah to take advantage of the political situation. Hoorah! I say, take a negative and turn it into a positive.

We will go to the moon again. Now we just need to make sure we don't get into too much trouble in our homeworld... I don't want this to be the last time we go.

I would love to hear Hans Mark's opinion of this. He was (under?) Secretary of the Air Force and NASA's director during the first Shuttle Missions. He is a physics PhD who was sent by the AF to be the liason to the German scientists during Mercury and Apollo. He was also my Orbital Mechanics teacher in college

https://en.m.wikipedia.org/wiki/Apollo_8

Quote from: J. Wilhelm on March 01, 2017, 08:37:46 PM
Well, I guess it makes sense that they'd choose that type of flight. It has been done before, and it'd be the equivalent of the Apollo 8 mission. The orbital mechanics are exactly the same, and like Apollo 8 you're still risking the life of the crew. It all comes down to the confidence in the reliability of Dragon's systems. Musk did say NASA would get first dibbs on the flight, so we may see American Astronauts go before the tourists.

With the current political climate, this is a silver lining on the black cloud, because a manned moon shot is one of America's greatest achievemens. This is a feather on the political cap of our president  ::)

(snip)

Also, it looks like they want to time it for the 50Th anniversary of Apollo 8.

Yours,
Miranda.

Quote from: Miranda.T on March 01, 2017, 11:16:35 PM

Quote from: J. Wilhelm on March 01, 2017, 08:37:46 PM
Well, I guess it makes sense that they'd choose that type of flight. It has been done before, and it'd be the equivalent of the Apollo 8 mission. The orbital mechanics are exactly the same, and like Apollo 8 you're still risking the life of the crew. It all comes down to the confidence in the reliability of Dragon's systems. Musk did say NASA would get first dibbs on the flight, so we may see American Astronauts go before the tourists.

With the current political climate, this is a silver lining on the black cloud, because a manned moon shot is one of America's greatest achievemens. This is a feather on the political cap of our president  ::)

(snip)

Also, it looks like they want to time it for the 50Th anniversary of Apollo 8.

Yours,
Miranda.

Yep. I think Dr. Mark will get to see it. He's still alive. I knew him when he was close to 70 yrs old. Apparently he's still teaching at UT  :o if I know him better recounting all his advetures for half the lecture  ;D.   Errata: he retired from teaching 2 years ago. i I'd like to see him one more time before he passes on.

https://en.wikipedia.org/wiki/Hans_Mark (https://en.wikipedia.org/wiki/Hans_Mark)

http://www.ae.utexas.edu/faculty/faculty-directory/mark (http://www.ae.utexas.edu/faculty/faculty-directory/mark)

I wonder if they'll have a watching party.

Something I hadn't realized: apparently, late last year our own Austin-based Firefly Space Systems, a startup whose purpose was to launch micro-satellite clusters, was placed on an "induced coma." They have furloughed all employees and are seeking new investors.

http://spacenews.com/firefly-space-systems-furloughs-staff-after-investor-backs-out/ (http://spacenews.com/firefly-space-systems-furloughs-staff-after-investor-backs-out/)

http://www.fireflyspace.com/ (http://www.fireflyspace.com/)

https://en.wikipedia.org/wiki/Firefly_Space_Systems (https://en.wikipedia.org/wiki/Firefly_Space_Systems)

Apparently a major European investor pulled out at the last minute as a consequence of Brexit  :-\ No wonder I never heard from them after applying.

March 9, birthday Gagarin

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Fsm.evg-rumjantsev.ru%2F1cosm%2F005.jpg&hash=128d023db5fd43ef12c445683e36f28a472c76d9)

Quote from: morozow on March 09, 2017, 06:40:19 PM
March 9, birthday Gagarin

(https://brassgoggles.net/forum/proxy.php?request=http%3A%2F%2Fsm.evg-rumjantsev.ru%2F1cosm%2F005.jpg&hash=128d023db5fd43ef12c445683e36f28a472c76d9)

One if the most select and brave groups ever - the founding figures of spaceflight. All of those early pioneers, both Russian and American, certainly had 'the right stuff' in bucketloads.

It should of course be noted that yesterday was another historic day - SpaceX's landing of a refurbished rocket stage from an orbital mission. Things are suddenly moving along a pace, pushed by SpaceX and Blue Origin. A commercial rivalry there should be a good thing, rapidly driving forward new developments, but hopefully with safety always foremost in mind.

Yours,
Miranda.

Part 1 : Stage 1 Ascent and Stage 2 Climb to Geostationary Orbit; Stage 1 Descent and landing video was lost


SpaceX SES-10 Launch and First Stage Landing (http://youtube.com/watch?v=T6tiEk9eFxE#)

Part 2:  Same as above but with commentary + Stage 2 Separation and Payload Geostationary Orbit Insertion plus commentary

The second video gives you a lot of commentary and explanation as to what you just saw above. It is however a SpaceX sponsored web cast and as such it puts a lot of spin and hooplah into the event. I don't think that the Apollo crew, engineers and ground crew ever had so much cheering in the background  :D

SES-10 Hosted Webcast (http://www.youtube.com/watch?v=xsZSXav4wI8#)

I suspect the lost landing video might lead some conspiracy theorists to start spinning some "alternate facts"  ::)

Quote from: J. Wilhelm on April 03, 2017, 03:05:18 AM

I suspect the lost landing video might lead some conspiracy theorists to start spinning some "alternate facts"  ::)

We have already started. Jealous.

Quote from: morozow on April 03, 2017, 07:07:56 AM

Quote from: J. Wilhelm on April 03, 2017, 03:05:18 AM

I suspect the lost landing video might lead some conspiracy theorists to start spinning some "alternate facts"  ::)

We have already started. Jealous.

Well. You heard it here first! They've already started!!  :D  :D  :D

Quote from: J. Wilhelm on April 03, 2017, 08:19:26 AM

Quote from: morozow on April 03, 2017, 07:07:56 AM

Quote from: J. Wilhelm on April 03, 2017, 03:05:18 AM

I suspect the lost landing video might lead some conspiracy theorists to start spinning some "alternate facts"  ::)

We have already started. Jealous.

Well. You heard it here first! They've already started!!  :D  :D  :D

There are always people who are looking for the catch in everything. And when there is an internal explanation to seek him ...

But it was just a discussion of this event on the forum of the game EVE-online. Only individual characters. Two.

And again April 12 the international day of cosmonautics


Ю Гагарин Поехали! Y Gagarin Poehali! (http://www.youtube.com/watch?time_continue=17&v=fPZTCrrPvYI#)

Oh sweet Jesus, Mary mother of God!

http://www.bbc.com/news/technology-39803425 (http://www.bbc.com/news/technology-39803425)

So what do I read on the BBC today? Apparently NASA is holding a contest (available to US citizens only) to see if someone can re-write a particular subroutine of a fluid dynamics programme suite called FUN3D. Given my experience in high speed flow (this was my exact areas of experitise), this must either be a Navier Stokes Finite Volume  solver or if not, at least an Euler Equations solver (like the one we discussed a few pages ago vis-a-vis the HOTOL hypersonic vehicle).

No listen to this: The programme is written in FORTRAN  ::)  :D I think I may be one of the only few dinosaurs out there who still know how to program in FORTRAN (Fortran 77, 90 and 95 in my case). In fact all of my code in my college years was FORTRAN  ;D

The purpose of the contest is to speed up the execution of that particular subroutine by a few thousand times if possible. The prize is $55 000 USD to be split between the first and second place winners.

*Sigh* what do I do?  ::) Of course there is no indication or expectation that I could be better than any other contestant. Other thah the fact that I'm old and I know the language  ;D And for all I care the code is obtuse, poorly annotated, and mind numbingly convoluted. As it usually is. I HATE rewriting code, and yet that's all I did back circa 1997.

https://fun3d.larc.nasa.gov/chapter-1.html (https://fun3d.larc.nasa.gov/chapter-1.html)
https://software.nasa.gov/software/LAR-18968-1 (https://software.nasa.gov/software/LAR-18968-1)

I'll see if I can request the stupid thing. It'd be fun to run it in a cluster headed by my Steampunk Linux PC  ;D


PS Another interesting story:

Chinese farmer DIY's design, build and fly their own aircraft:

http://www.bbc.com/culture/story/20170312-the-amazing-flying-machines-of-chinese-farmers (http://www.bbc.com/culture/story/20170312-the-amazing-flying-machines-of-chinese-farmers)

Quote from: J. Wilhelm on May 16, 2017, 06:49:55 AM
Apparently NASA is holding a contest (available to US citizens only) to see if someone can re-write a particular subroutine of a fluid dynamics programme suite called FUN3D. Given my experience in high speed flow (this was my exact areas of experitise),....

Go for it J.
Was Die Hölle, where's the harm?  it might be a foot-in-the-door !

Quote
No listen to this: The programme is written in FORTRAN  ::)  :D I think I may be one of the only few dinosaurs out there who still know how to program in FORTRAN (Fortran 77, 90 and 95 in my case). In fact all of my code in my college years was FORTRAN  ;D

Yah, you and me both, brother.

Quote
The purpose of the contest is to speed up the execution of that particular subroutine by a few thousand times if possible.

Well, you know the math, so why not go forit? In fact you might try 2 ways
a) the way it's spec'd, all in Fortran, and
2) by using external calls to your own new code you know executes faster, like "C" ? 

Most of  "The Kids" will either stick with Fortran, or try to rewrite in JAVA and fail miserably since JAVA is 1000 times slower  !   :D :D :D :D :D

yhs
prof curmudgeon

My Dear J -

I went over to look at the links....

this *has* to be designed using parallel processing, nicht war? If so, perhaps the paralellisation is a bottleneck?
are they using flags, semaphores, shared memory, interrupts, wait-states, signals ( unix sig )?

or is it hardware specific, hardware bound or hardware independant? that alone can kill ya as we saw in the days
of the Sun "t-series". code had to be redesigned to take advantage of the "look-ahead" crap, pipes,  &etc...

If you can get a look at "the big picture" you can then see where the bottlenecks really occur and where any fixes/changes will actually help.
That "used to be" one of my specialties.


Oh Dear - I looked at their links. Their process is nothing new, same old stuff touted as "new" in the 80's and 90' and 00's, just changed labels:

Agile Software - nothing new, except for the feature where it allows the customer  to continuously interfere.
                Try that with your plumber and see how it works out.

Extreme Programming: again not much new - except for Pair programming

   Pair programming is an agile software development technique in which two programmers work together
   at one workstation. One, the driver, writes code while the other, the observer or navigator, reviews
   each line of code as it is typed in. The two programmers switch roles frequently

Oh yesssss I love having somebody back-seat driving looking over my shoulder criticizing every choice I make and
every fat finger typo that happens - We can see it works out great with Sheldon on "The Big Bang Theory"
I fear it would end in death and dismemberment!

What actually works better is "ego-less programming and peer review" where the team meets regularly and discusses selected code
without knowing who wrote it.

OMG then I see this:
http://wiki.c2.com/?TruckNumber (http://wiki.c2.com/?TruckNumber)
a bunch of real word Sheldons arguing the semantics over the "Truck Number" - ie exactly how many *essential* people you can afford to lose
on a project and not fail - thru vacation, accident, or  "just fed up and f***ing leaving"  (probably due to this exact topic being taken seriously) .

The answer is simple-
a) except for a one-man project, no single person is ever irreplaceable - it will cost time, but that's it.
b) dont put all your people in one basket vehicle

My Dear J -
On second thought, I am (again) glad I am out of it! its just SSDD.
go for the prize, but don't get invovled in the insanity!

yhs
prof marveling that he lived thru it to retire

Well I know we're not gonna use vector computations  ;D Of course, it requires parallel computation, but I suspect it is the algorithms in the subroutines which they are targetting. I'm not a computer hardware expert. That is not my department. I do physics. Direct simulation of high speed aerothermodynamics of a viscous compressible flow.  I optimize subroutines in the sense of the mathematical methods use to perform the computations. There should be a good deal of matrix and tensor operators coded in the subroutines. An upwind finite volume solver with an unstructured grid, adapting or not is standard for processing the Euler or Navier Stokes Equations in high speed flows.

There are methods to "compress" the processing of data, in terms of the mathematical physics, apart from the coding itself and no matter which computational bottlenecks you are facing in distributed (parallel) computing, it boils down to the physics of the problem to allow you the gratest possible time versus precision compromise. It may be up to the CFD subroutines to determine how fast and precise the program is.

Short of a wholesale redesign of the algorithm, you might find substantial gains reworking the order in which cells are calculated to increase the odds the data you need is in L1 cache.  But a thousand fold improvement in speed typically requires a new algorithm.  Fortran, especially run through a modern compiler, shouldn't be that bad for speed.

Quote from: Peter Brassbeard on May 19, 2017, 04:40:33 PM
Short of a wholesale redesign of the algorithm, you might find substantial gains reworking the order in which cells are calculated to increase the odds the data you need is in L1 cache.  But a thousand fold improvement in speed typically requires a new algorithm.  Fortran, especially run through a modern compiler, shouldn't be that bad for speed.

That's the thing. Fortran is so simple. First I need to see the First Principles theory used. I imagine that is boilerplate fluid mechanics. Then I need to see type of CFD DNS solver they're using, the grid generator and how it's used by the solver (where I suspect a lot of savings could be generated). There will be mathematical theory that can be applied to the grids in order to optimize the solution in every cell, and the solver it self, I need to look at it to see if there is a better mathematical method - though I suspect they've looked at that many times). Then I need to take a look at the subroutines. See what they're doing, and how convoluted the overall structure of the program is, and in what order things are called. Lastly all of what Prof. Marvel mentioned, would be looked at, by me or someone more educated in the hardware. Everything will be very modular, but looking at someone else's code is always excruciating.

Awaiting further progress reports with considerable anticipation.  :)

Quote from: Banfili on May 20, 2017, 12:42:14 AM
Awaiting further progress reports with considerable anticipation.  :)

Don't hold your breath! I don't know when I'll start and even if I could finish! I just want to take a look at it. I'd be advantageous though to have a coding expert though. I can do the physical theory, grid generators and the DNS methods but I suspect I'm a poor programmer,even if I know Fortran.

Quote from: Peter Brassbeard on May 19, 2017, 04:40:33 PM
Short of a wholesale redesign of the algorithm, you might find substantial gains reworking the order in which cells are calculated to increase the odds the data you need is in L1 cache.  But a thousand fold improvement in speed typically requires a new algorithm.  Fortran, especially run through a modern compiler, shouldn't be that bad for speed.

Actually a wholesale redesign is probably what is needed  ;D  that falls even more under my field of expertise  ;D It's always easier to start anew, but understanding what the old code did so you can actually improve everything. Basically the best bet is to write a new solver.

I have every confidence!
:D

For those mad scientists among us, I give you a genetically engineered cyborg firefly drone equipped with a tiny solar panel.

http://www.bbc.com/news/av/technology-40508099/living-dragonfly-drones-take-flight (http://www.bbc.com/news/av/technology-40508099/living-dragonfly-drones-take-flight)

QuoteDraper's Dragonfl-eye is a living dragonfly with a solar-powered backpack that can control its movements using light pulses.

By genetically engineering the "steering neurons" of the dragonfly, researchers hope to be able to use the insect to get to areas larger drones cannot reach.

Alright, here we go again. Elon Musk is out to surprise us again. He just unveiled a new reusable rocket hybrid he plans to have flying by 2022. That is not the surprising part. He plans to have the "joint strike fighter" equivalent of the rocket world, by having one single type of hypersonic /rocket hybrid SSTO vehicle capable of city to city travel, low orbital payload delivery, and... interplanetary travel. No joke.

He envisions nothing short of a 1999 Space Odyssey scenario with intra orbital travel,

He could be a genius or a mad man. While his achievement in reusable rocket technology is impressive, experience shows us that "joint" multi purpose vehicles are much harder to implement, because a lot of things can go wrong. For example the F-111 Aardvark (General Dynamics? Not to mention our own present day F-35 joint strike fighter by Lockheed Martin.

http://www.bbc.com/news/science-environment-41441877 (http://www.bbc.com/news/science-environment-41441877)

Much as I would like to see it, I am firstly concerened about "commuter rockets" - mainly safety & pollution. rockets are notorious for using toxic fuels and polluting far more than other engines - and its all to cater to "other rich bastards" who think they are more important than the rest of us.

Also, I have become disenchanted with The Musker in general. He seems to get a wet dream in the shower and then makes huge announcements, sometimes claimng he already has "verbal government support" , which in reality is nonexistant.

Lastly, for all the happy happy joy joy stuff he has managed to pull off, (ie some small successes with his private rockets and the Tesla car)  his Tesla Electric Car is STILL powered by Chinese AA cells, and the slaves drones employees in his Nevada Tesla Sweatshop are being worked to death....

I find it is just history repeating itself ( as in the 180's -1890's prior to workers unions )

prof grumpy....

To be honest with you I haven't read much about it. I'm unclear if this a single stage or multiple stage, boosters or no boosters, and just considering the fuel requirements for an interplanetary mission versus a low Earth orbit mission gives me serious doubts about the "one size fits all" claim. My understanding is that not only do you need to reach escape velocity for Earth, but then you will need to chose a transfer orbit, a fast and expensive one like the "figure 8" used for the Apollo missions or a slow cheap one like a Hohmann transfer orbit (a simple ellipse connecting the two orbits around the celestial bodies).

Take into account that as much as Musk touts himself as "chief designer," he is in fact no engineer. Others are doing all the work. He's more like Howard Hughes was, a millionaire with big dreams and bigger demands from his staff.

On the battery issue it is important to follow the recent achievements by the staff of the very wise and very old Professor Goodenough at the University of Texas at Austin. Solid State batteries with liquid crystal electrolyte layers which not only triple the energy density, but prevents dendrites forming between electrodes - thus no spontaneous fires. Sadly Tesla Motors has not made an effort to acquire this technology.

Quote from: J. Wilhelm on September 29, 2017, 10:45:22 PM
To be honest with you I haven't read much about it. I'm unclear if this a single stage or multiple stage, boosters or no boosters, and just considering the fuel requirements for an interplanetary mission versus a low Earth orbit mission gives me serious doubts about the "one size fits all" claim. My understanding is that not only do you need to reach escape velocity for Earth, but then you will need to chose a transfer orbit, a fast and expensive one like the "figure 8" used for the Apollo missions or a slow cheap one like a Hohmann transfer orbit (a simple ellipse connecting the two orbits around the celestial bodies).

Take into account that as much as Musk touts himself as "chief designer," he is in fact no engineer. Others are doing all the work. He's more like Howard Hughes was, a millionaire with big dreams and bigger demands from his staff.

Their biggest problem will be that, rather than using a small number of large engines (the Saturn V model), they will apparently be using 30-some-odd smaller engines. The massive challenge is getting all of these to work in synchronisation - the difficultly of this is what doomed Korolev's N1. Of course, technology has moved on rather a lot since the 1960s so maybe they can tame that issue.

In terms of multi-use, from the brief information I've seen the plan for the beyond Earth-orbit missions is to put the spacecraft into orbit and then move on from there at a later point - presumably after a refueling mission or two. Anyway, as I always say, before spending two to three years on a Mars mission whoever is going there should go to the moon first and use that to test and perfect the the systems that would be needed for the Mars mission. Better to spend 10-15 years thoroughly preparing for a successful mission than rush there and risk disaster.

Yours,
Miranda.

P.S. It's the 50th anniversary this year of the first flight of the Saturn V.

Quote from: Miranda.T on September 30, 2017, 06:08:02 PM

Quote from: J. Wilhelm on September 29, 2017, 10:45:22 PM
To be honest with you I haven't read much about it. I'm unclear if this a single stage or multiple stage, boosters or no boosters, and just considering the fuel requirements for an interplanetary mission versus a low Earth orbit mission gives me serious doubts about the "one size fits all" claim. My understanding is that not only do you need to reach escape velocity for Earth, but then you will need to chose a transfer orbit, a fast and expensive one like the "figure 8" used for the Apollo missions or a slow cheap one like a Hohmann transfer orbit (a simple ellipse connecting the two orbits around the celestial bodies).

Take into account that as much as Musk touts himself as "chief designer," he is in fact no engineer. Others are doing all the work. He's more like Howard Hughes was, a millionaire with big dreams and bigger demands from his staff.

Their biggest problem will be that, rather than using a small number of large engines (the Saturn V model), they will apparently be using 30-some-odd smaller engines. The massive challenge is getting all of these to work in synchronisation - the difficultly of this is what doomed Korolev's N1. Of course, technology has moved on rather a lot since the 1960s so maybe they can tame that issue.

In terms of multi-use, from the brief information I've seen the plan for the beyond Earth-orbit missions is to put the spacecraft into orbit and then move on from there at a later point - presumably after a refueling mission or two. Anyway, as I always say, before spending two to three years on a Mars mission whoever is going there should go to the moon first and use that to test and perfect the the systems that would be needed for the Mars mission. Better to spend 10-15 years thoroughly preparing for a successful mission than rush there and risk disaster.

Yours,
Miranda.

P.S. It's the 50th anniversary this year of the first flight of the Saturn V.

Indeed. Lots of issues to tackle. Oh well. Much better see someone trying to accomplish big dreams, than people in a moribund space agency doing nothing. Half of my job as an engineer , I naively thought as a student, was dreaming. When adult life came around me, and as someone irreverently joked "took a dump on my head" I think a lot of possibilities were lost. I don't think that any Human Resources recruiters will ever know how many potential dreams are being bypassed


50 years. That reminds me how old I am... I'm a walking museum, practically.

Oh yeah. I forgot. If you check the news lately, you'll find that Bombardier is now embroiled in a trade war between Canada and the US. A really serious sum of money in the billions of dollars between American Airlines and Bombardier is on the chopping block...

Uber and NASA to develop Sky Taxis by 2020? I just hope they plan on developing 4 rotor VTOL vehicles and not the mostly dangerous 2-rotor design used in the V-22...

http://www.msn.com/en-us/news/technology/flying-taxis-uber-and-nasa-just-paired-up-to-make-that-happen/ar-BBEIAWl (http://www.msn.com/en-us/news/technology/flying-taxis-uber-and-nasa-just-paired-up-to-make-that-happen/ar-BBEIAWl)

QuoteUber is taking a big step towards making its vision of flying vehicles a reality, announcing on Wednesday an agreement with NASA to develop a fleet of air taxis by 2020.

While the ride-hailing service and the U.S. space agency may seem like an odd couple, the relationship is necessary in order to keep everything running smoothly when Uber ultimately takes to the skies.

"The space act that we signed with NASA is initially about collaboration around air traffic management," Jeff Holden, Uber's chief product officer, told NBC News. With so many aerial vehicles flying at a low attitude, the collaboration will be necessary to help manage the skies.

Uber also announced that Los Angeles will be the second U.S. city where it will test its uberAIR service. Dallas-Fort Worth is the first U.S. launch partner, while Dubai will be the first global city.

Holden said he expects Uber will have its first flight demonstrations in 2020 and have the service commercially available by 2023. That's well ahead of the 2028 Olympics in Los Angeles, where the service could be especially useful as an already congested city prepares to host athletes and fans from around the world.

Uber's air travel initiative was announced last October with the promise of putting an end to long commutes, letting passengers hail an aircraft ride with the push of a button. In the case of Los Angeles, Uber has 20 strategically placed locations around the city for the Uber network.

The idea is to build a network of vertical takeoff and landing aircraft that would greatly reduce commutes, while also helping to ease vehicle pollution in major cities.

In a video released Wednesday by Uber, the company showed what it will be like to order a seat on one of the aircraft, which will take off and land vertically.

"It's an inspirational way to travel, too," said Holden. "You push a button, fly over the city, and you land. No volatility."

Quote from: J. Wilhelm on November 08, 2017, 11:46:08 PM
Uber and NASA to develop Sky Taxis by 2020? I just hope they plan on developing 4 rotor VTOL vehicles and not the mostly dangerous 2-rotor design used in the V-22...

http://www.msn.com/en-us/news/technology/flying-taxis-uber-and-nasa-just-paired-up-to-make-that-happen/ar-BBEIAWl (http://www.msn.com/en-us/news/technology/flying-taxis-uber-and-nasa-just-paired-up-to-make-that-happen/ar-BBEIAWl)

(https://pbs.twimg.com/media/DOJe3bIUIAALhbC.jpg)

QuoteUber is taking a big step towards making its vision of flying vehicles a reality, announcing on Wednesday an agreement with NASA to develop a fleet of air taxis by 2020.

While the ride-hailing service and the U.S. space agency may seem like an odd couple, the relationship is necessary in order to keep everything running smoothly when Uber ultimately takes to the skies.

"The space act that we signed with NASA is initially about collaboration around air traffic management," Jeff Holden, Uber's chief product officer, told NBC News. With so many aerial vehicles flying at a low attitude, the collaboration will be necessary to help manage the skies.

Uber also announced that Los Angeles will be the second U.S. city where it will test its uberAIR service. Dallas-Fort Worth is the first U.S. launch partner, while Dubai will be the first global city.

Holden said he expects Uber will have its first flight demonstrations in 2020 and have the service commercially available by 2023. That's well ahead of the 2028 Olympics in Los Angeles, where the service could be especially useful as an already congested city prepares to host athletes and fans from around the world.

Uber's air travel initiative was announced last October with the promise of putting an end to long commutes, letting passengers hail an aircraft ride with the push of a button. In the case of Los Angeles, Uber has 20 strategically placed locations around the city for the Uber network.

The idea is to build a network of vertical takeoff and landing aircraft that would greatly reduce commutes, while also helping to ease vehicle pollution in major cities.

In a video released Wednesday by Uber, the company showed what it will be like to order a seat on one of the aircraft, which will take off and land vertically.

"It's an inspirational way to travel, too," said Holden. "You push a button, fly over the city, and you land. No volatility."

And have you seen this crazy contraption the Volocopter? The first 2 passenger Volocopter flew last year and it's being considered for air taxi projects to come very soon. Basically a Volocopter os just an electric drone. I don't think Uber will use this one in particular as they just announced a development programme with NASA (see my last post)

Dawn of a revolution in urban mobility - first manned flight with the Volocopter VC200 (http://youtube.com/watch?v=OazFiIhwAEs#)

In the news feed:

Static firing of SpaceX's Falcon Heavy two days ago... ahead of a launch scheduled for Frebruary 6. Controlling 27 engines simultaneosuly is always a bit tricky. That was one of the reasons why the Russian "Moon Shot" never happened... If they succeed, Falcon Heavy will be the most powerful rocket in operation... at least until NASA's Space Launch System (SLS) high capacity vehicle becomes a reality.

SpaceX - Falcon Heavy Static Fire 2018.01.24 (http://www.youtube.com/watch?v=8ZZs1pxqB9c#)

The Soviet N-1 didn't have modern silicon pixie-aetherwave controller technology.  And signs suggest SLS schedule will continue to slip until eventual cancellation.

Quote from: Peter Brassbeard on January 30, 2018, 01:31:21 AM
The Soviet N-1 didn't have modern silicon pixie-aetherwave controller technology.  And signs suggest SLS schedule will continue to slip until eventual cancellation.

Shame, really. We're not very serious about having a national space program, whereas a few visionaries like Musk are left to carry the basket. Not complaining, I think he's doing a great job, and given that he's one a single few who are trying, I guess I'll forgive him the eccentricity of launching his cherry red Tesla coupe past Mars.

I do envy the Indian space programme, though. My whole adult existence was based on the never materialised promise of working on something similar to the Space Shuttle.

Well here it is, the three-core, two-stage Falcon Heavy rocket was launched today from Cape Canaveral with its "Space Oddity" payload, Musk's own Tesla Roadster:

SpaceX Falcon Heavy launch (http://www.youtube.com/watch?v=sB_nEtZxPog#)

I must say, they did organize a good party on the ground...  :D

The cat's out of the bag on the destiny of the Tesla roadster. If I understand correctly (correct me if I'm wrong or missed something or I read something wrong) the Tesla, now christened "Starman," will traverse an orbit past the sun to an apogee that nearly matches the farthest distance from the Earth to Mars (400 million Km). The implication is that the Tesla roadster will be captured by the Sun's gravity (hyperbolic orbit during slingshot, then elliptical again toward Mars)*, and attain a highly elliptical orbit that will interesect all the inner planet's near-circular orbits, while playing David Bowie's "Space Oddity" (in the vaccum if space, so no one will hear it  ;D). So there is a microscopic chance of colliding with any of the inner planets in the very distant future or burning in Earth's atmosphere. But most likely it is now just another, very odd and queer metal, plastic and rubber meteor.  ;D

*Edit: Big correction here. They released the orbital path. The Sun is nowhere close to being between Mars and Earth, so the Starman was actually launched directly toward Mars but not close enough to Mars and way too fast to get captured by Mars. Instead the Sun's stronger gravity will determine its fate. Still that is way more energy than I anticipated in the upper stage.

Because the Starman was travelling so much faster than I thought, the orbit is a lot less eccentric than I anticipated. While still eccentric, the orbit is a much "fatter" orbit that does not need a "slingshot" past any celestial body, and instead only allows the Sun to capture the Starman away from Earth's (and Mars') gravitational pull.

I was not expecting that. The orbit has so much energy (Starman 's speed) that its orbit does not even intersect the orbits of Venus and Mercury, it just lies outside their orbits, going around them altogether. That is one hell of a shot.


PS I wonder what happened to that wheel of cheese aboard the Dragon/Falcon 9 in 2010... did they serve it at the party?

Apparently there is a third (upper stage) still attached to the Tesla ("Starman") . The idea is to do  a final burn to aim for Mars. Some interesting live video from the 3 cameras. A mannequin dressed in a space suit is sitting in the driver's seat. This is your chance to make a memorable screen saver. I just did mine :

(Live feed from @SpaceX)
https://youtube.com/watch?v=aBr2kKAHN6M


Cheers,

JW

I'm glad the launch went well - if any 'visitors' manage to snag that car, they are going to wonder what the hell happened!
Love the "Don't Panic" touch in the roadster! ;D

Quote from: Banfili on February 06, 2018, 11:38:04 PM
I'm glad the launch went well - if any 'visitors' manage to snag that car, they are going to wonder what the hell happened!
Love the "Don't Panic" touch in the roadster! ;D

Well, for one, they'd wonder why people on Earth are so stiff  :P Watching the Live feed now, I'm waiting for the second biurn. I think I see some liquid drops coming out of the left front hand side of the car...  ::)

Congratulations on Cosmonautics Day!

(https://cs9.pikabu.ru/post_img/2019/04/12/5/1555051640153744306.jpg)

Quote from: morozow on April 12, 2019, 08:20:43 AM
Congratulations on Cosmonautics Day!

(https://cs9.pikabu.ru/post_img/2019/04/12/5/1555051640153744306.jpg)

We need to celebrate advances in space exploration more. It's just a foot note or small print in nespapers nowadays.

On the eve once again was a good event. Max has a heavy Falcon. And Israeli satellite reached the moon, though not prizemlilsya, but still.

Quote from: morozow on April 12, 2019, 11:12:18 PM
On the eve once again was a good event. Max has a heavy Falcon. And Israeli satellite reached the moon, though not prizemlilsya, but still.

More changes are coming. New people are coming in after developed countries. When India launched a probe to Mars, very few people paid any attention. Most people I talk to don't even know India had a small prototype space shuttle. I'm hoping more countries will participate. I don't regret new companies like "SpaceX," because they're bringing back retro-rocket type technology that was abandoned in the late 1960s, but SpaceX is still a limited endevour, and hypersonic space-planes in US and Europe are now just on the desks of military services.

Quote from: J. Wilhelm on February 06, 2018, 11:21:00 PM
Apparently there is a third (upper stage) still attached to the Tesla ("Starman") . The idea is to do  a final burn to aim for Mars. Some interesting live video from the 3 cameras. A mannequin dressed in a space suit is sitting in the driver's seat. This is your chance to make a memorable screen saver. I just did mine :

(Live feed from @SpaceX)
https://youtube.com/watch?v=aBr2kKAHN6M

(https://pbs.twimg.com/media/DVY1MVgVwAADhiN?format=jpg)

Cheers,

JW

looks like an homage to the ancient animated movie "Heavy Metal" ....

yhs
prof marvel

Quote from: J. Wilhelm on April 12, 2019, 11:37:21 PM

Quote from: morozow on April 12, 2019, 11:12:18 PM
On the eve once again was a good event. Max has a heavy Falcon. And Israeli satellite reached the moon, though not prizemlilsya, but still.

More changes are coming. New people are coming in after developed countries. When India launched a probe to Mars, very few people paid any attention. Most people I talk to don't even know India had a small prototype space shuttle. I'm hoping more countries will participate. I don't regret new companies like "SpaceX," because they're bringing back retro-rocket type technology that was abandoned in the late 1960s, but SpaceX is still a limited endevour, and hypersonic space-planes in US and Europe are now just on the desks of military services.

India, Israel, Japan ( sent a satellite to explore an asteroid! can you say asteroid mining?) and China.

Except for private efforts, it looks like the US is out of it. The Great Unwashed doesn't care for anything but pizza, beer and foot/basket.baseball.

yhs
prof marvel

Well, SABRE just passed another important test (https://www.bbc.co.uk/news/science-environment-47832920 (https://www.bbc.co.uk/news/science-environment-47832920)) and, wheather it's in a SSTO or TSTO vehicle, hopefully it will get a chance to power something up to orbit by the end of the 2020s. Also, there seems to finally be a real push to the moon (https://www.space.com/lockheed-early-gateway-moon-2024-landing-plans.html (https://www.space.com/lockheed-early-gateway-moon-2024-landing-plans.html)). In terms of the latter, I'm wondering why the sudden rush? Is it simply national pride, or have the powers that be decided there is something of real interest on the moon? Maybe someone is quietly on the verge of commercial fusion using He-3, or maybe the recent Chinese probes have glimpsed the outline of a black obelisk...

Yours,
Miranda.

Quote from: Prof Marvel on April 13, 2019, 09:37:59 AM

Quote from: J. Wilhelm on April 12, 2019, 11:37:21 PM

Quote from: morozow on April 12, 2019, 11:12:18 PM
On the eve once again was a good event. Max has a heavy Falcon. And Israeli satellite reached the moon, though not prizemlilsya, but still.

More changes are coming. New people are coming in after developed countries. When India launched a probe to Mars, very few people paid any attention. Most people I talk to don't even know India had a small prototype space shuttle. I'm hoping more countries will participate. I don't regret new companies like "SpaceX," because they're bringing back retro-rocket type technology that was abandoned in the late 1960s, but SpaceX is still a limited endevour, and hypersonic space-planes in US and Europe are now just on the desks of military services.

India, Israel, Japan ( sent a satellite to explore an asteroid! can you say asteroid mining?) and China.

Except for private efforts, it looks like the US is out of it. The Great Unwashed doesn't care for anything but pizza, beer and foot/basket.baseball.

yhs
prof marvel

Unfortunately it is turning out to be that way. All we have today is politics. There are no dreams anymore, other than politically beating the other 50% of your countrymen at the polls. At best the hope for many seems to go back to 1955, as some sort of horribly misguided nostalgia for the past.

Quote from: Miranda.T on April 13, 2019, 12:10:51 PM
Well, SABRE just passed another important test (https://www.bbc.co.uk/news/science-environment-47832920 (https://www.bbc.co.uk/news/science-environment-47832920)) and, wheather it's in a SSTO or TSTO vehicle, hopefully it will get a chance to power something up to orbit by the end of the 2020s. *snip*

It's great news to hear about any progress on that side. If liquefying air can be done to generate the oxidizer, and the engines can be used is low supersonic range through Mach 5-6 when you will need to rely on liquid oxygen (basically), then this will be the only working engine capable of achieving horizontal ascent to orbit. For some reason SCRAMJET engines we never made reliable.

The presumtion is that generating the proper mixing of fuel and oxygen in a supersonic turbulent flow is unreliable at best, as shown in SCRAMJET technology. A supersonic turbulent boundary layer is simply not understood yet; we don't have a picture of what happens when there is a range of speeds from zero through suprsonic in turbulent boundary layers.  We've made great strides in understanding and (hence controlling) *subsonic* turbulence for incompressible flows, like water flowing over a flat surface, using Spectral DNS methods (Full Navier Stokes simulations using sine wave Fourier Transforms to process differential equations - what I used to do in my second stint in graduate school). But the supersonic turbulent BL has to be a very complex and severe environment for air. Ther large amount of heat generated by friction inside the boundary layer affects the mass density of the flow and the turbulent air becomes even more viscous* and that in turn affects the nature of turbulence.

In this case, you want to maximize turbulence to promote mixing of fuel and oxygen. There may be statistically emergent properties that we haven't discovered yet. Not knowing how to sustain combustion in supersonic flow forces you to slow down the intake of air to subsonic speeds in the combustion chamber. Normally we do that anyway in supersonic craft, because turbojet compressors and turbines are not designed to handle supersonic flows at all, but in theory, Ramjets eliminate all moving parts - that was the best hope for supersonic compression before combustion.

The Sabre engine bypasses all that by foregoing any mixing at any speed. It simply brings to near stant still (hot) air into the combustion chamber, or plain liquifies the oxygen (cold) which you then use in the combustion chamber - basically like a regular rocket. The idea was pure genius from the beginning, and it's no wonder it eluded all other engineering projects; it brings the speed of the oxidizer to zero! Engineers' attempts at handling oxygen all involved slowing air down, but saving the kinetic energy in the form of pressure energy and heat. The argument being a thermodynamic one, in that one should not dissipate the thermal energy of a compressed airflow, because then you have to make up for it later on by burning more fuel. And it's NOT a small loss in energy. The amount of energy stored in hot gas can be tremendous, you don't want to let it go. It's a mantra we have use to design air breathing engines since the first British centrifugal turbojets. The turbine is the part of the engine tasked with recovering that pressure and temperature and directing the energy back into kinetic energy in the form of a jet of air. By then all heat you lose in that exit nozzle of hot exhaust is the net loss for the engine (usually not a small amount of energy loss; jet engines -Brayton Cycle- are very lossy compared to your car's 4-stroke internal combustion engine).

But in this case the mantra is wrong because the physics don't seem to let us perform the combustion beyond a certain speed. And you can't ram all that air you need into a conventional turbojet. It simply gets too hot for the engine parts to handle. The thermodynamic efficiency goes to hell when you stop and cool the air like that, because the pre-cooler they've designed simply can't process ALL the heat so fast and recycle it into pressure energy. There will be large losses in thermal energy. But the alternative to that is nothing at all. And even with all that energy dissipation, the efficiency of the Sabre is STILL much better than a conventional rocket, simply because you don't have to carry all the oxygen with you. It's just thinking outside of the box.

QuoteUK engineers developing a novel propulsion system say their technology has passed another key milestone.
The Sabre air-breathing rocket engine is designed to drive space planes to orbit... the team at Reaction Engines Ltd has developed a heat-exchanger for the purpose. It has shown the ability to handle the simulated conditions of flying at more than three times the speed of sound. It did this by successfully quenching a 420C stream of gases in less than 1/20th of a second. The REL group is confident its "pre-cooler" technology can now go on to show the same performance in conditions that simulate flying above five times the speed of sound, or Mach 5.

*https://www.annualreviews.org/doi/abs/10.1146/annurev.fl.26.010194.001443
*https://www.sciencedirect.com/science/article/pii/S0142727X15000247

Quote from: Miranda.T on April 13, 2019, 12:10:51 PM
*snip* there seems to finally be a real push to the moon (https://www.space.com/lockheed-early-gateway-moon-2024-landing-plans.html (https://www.space.com/lockheed-early-gateway-moon-2024-landing-plans.html)). In terms of the latter, I'm wondering why the sudden rush? Is it simply national pride, or have the powers that be decided there is something of real interest on the moon? Maybe someone is quietly on the verge of commercial fusion using He-3, or maybe the recent Chinese probes have glimpsed the outline of a black obelisk...

Yours,
Miranda.

There is a valid argument about rehearsing extraterrestrial missions on the moon, or using the moon as a launch pad, or even exploiting the moon's resorces, but I see the endeavour somewhat flawed. I'm afraid it's not a black monolith or cold fusion what is driving us there. I'm under the impression this is part of the nostalgia trip the US seems to be suffering at the moment for the atomic age.  More about a 50-70 year old's pleasent childhood memories of winged cars and diners along Route 66, and the horrific nightmares of 1960s hippies handing out flowers in the street, and 1970s Disco dancing horrors like afros and cheap polyester suits. The time frame is set to coincide with a presumed Presidential re-election.

QuoteVice President Mike Pence, who is head of the National Space Council, directed NASA to speed up its plans to land humans on the moon and to target a human moon landing in 2024, or four years earlier than NASA had been planning. Now, the agency's commercial partners, who are providing much of the components for NASA's moon plans, must also scramble to meet the agency's new goal.

I fear the U.S. has been overcome by the greed for profit at any cost. 
space exploration , medicine, and public good have fallen by the wayside.

the other thing thing that concerns me is the ever growing chinese cyber threat. Everyone who used the much touted "Elemental Servers" is at risk,
This includes the Big Corporations worldwide as well as DOD, pentagon, and many 3 letter agencies.

Apple, Amazon, and Google quietly replaced some 7,000 to 10,000 servers (quite possibly more), and claimed  "never happened".

It all stems from some micro-microchips, about 2mm long, disguised as other components,
showing up on super-server motherboards that were outsourced to be manufactured in mainland china.

This article from Bloomberg Business week is pretty lengthy, but worth the time. it reads like a Tom Clancy book.

The Big Hack: How China Used a Tiny Chip to Infiltrate U.S. Companies

https://www.bloomberg.com/news/features/2018-10-04/the-big-hack-how-china-used-a-tiny-chip-to-infiltrate-america-s-top-companies?srnd=businessweek-v2 (https://www.bloomberg.com/news/features/2018-10-04/the-big-hack-how-china-used-a-tiny-chip-to-infiltrate-america-s-top-companies?srnd=businessweek-v2)

(i have downloaded text, html, and an image of the full article, along with footnotes and links, just in case the article somehow disappears....)

all i can say, is I am so friggin glad i am out of the business, and hiding in the foothills.

I am letting the next bunch of technonerds worry about all this crap, and sending little emails saying
"hey did you see this article? I told ya so ya stoopid barstiches!"

now it's spring, and time to fire up the greenhouse.  

I'll just be Wilfred Mott, gazing at the stars with my celestron

hoping  for a  "Bad Wolf"  to show up ( I do love me a good ontological paradox.  )

my celestron
(https://www.firstlightoptics.com/user/products/celestron_nexstar_127_slt.jpg)

Wilfred Mott, his telescope, and the tardis
(https://doctorwhocosplay.files.wordpress.com/2015/09/11949315_876757989056641_6123998049547258438_n.jpg)

Badd Wolf
(https://i.pinimg.com/originals/7d/1f/99/7d1f99abb0375cab4b9415eb3376dd15.png)


yhs
prof tired

Very interesting article. That does explain the odd marriage between brainless politics and security concerns regarding US Chinese trade tensions.

Wonderfully telling, and somewhat obvious that The first customers or Elemental would be televangelist religious organisations and the porn industry. I've always said porn drives the development of video technology  ::) :D

As to the security. It is touted that finding a Chinese military chip inserted into a motherboard at the manufacturing stage and then discovering the attack after somehow it was correctly distributed to the victim customers would be akin to finding a unicorn, according to Bloomberg.

The problem is that you're assuming that there is a localised target. There is not. Many companies use similar image compression servers (BTW I'm getting old, I haven't seen that server blade design before). That means that the Chinese government is targeting ANY kind of company using such servers. Then they build a global network to listen to the servers and somebody behind a terminal chooses which companies they want to listen to, assigning agents to target specific industries or companies.

Therefore you have to work on the assumption that ANY motherboard made in China is potentially compromised. Whether their government wants to spy on Apple technology or Apple customer's personal information or snoop into someone's late night visits to sketchy websites, is the prerogative of some bureaucrat.

So what to do? The answer lies in the supply chain. Doing what is described in in the article: the final seller MUST send the motherboards for inspection to a third party *regularly* checking that the motherboards are performing EXACTLY as you designed. There is no other way. The responsibility lies on the seller, who I'd make legally liable for damages. Claiming damages to the Chinese government is as useful as dog barking at a waterfall.

This means electronics costs will rise for the consumer due to the necessary inspections. But I can't see alternatives. Don't think you can avoid risk if instead of China you pick Singapore, for example, to make the motherboards. Sure, a Mexican or Singaporean motherboard will be less likely to be targeted, but that in itself is no guarantee.

And also remember: what's good for the goose is good for the gander. Now that we know, the US can retaliate in kind, regularly buying motherboards and analysing them for reverse hacking. It's something that is best done without announcing your intentions. These safety checks should be routine by now. The "scandal"  today is all about corporations being too innocent a decade ago to realise they were used as pawns.

And what makes you feel that this could not be exploited by individual actors as well? Google, Amazon, Apple can perform a bit of the same snooping of they choose to. Even individual actors strategically infiltrating a company can do it we can point the finger to China, but you may be dealing with a Stand Alone Complex, where multiple unrelated actors across the world are doing the same, leading you to believe that there is one boogeyman when in fact it's many.

The days when we have direct neural interface with the human brain will come sooner or later in this century. Then you will see some real hacking! In that sense, I'm glad neural networks (of the Machine Intelligence kind as defined by IEEE) embedded into the living brain are still not here, and instead all we have is digital simulations of neural networks, confined within conventional computers (Artificial Intelligence as defined by IEEE).

Hi J & Friends

sorry, this may seem like an off topic rant, but it really is all related to Aerospace in The Real World
if you stick with me to the end you'll understand.

Quote from: J. Wilhelm on April 14, 2019, 06:36:30 PM

The problem is that you're assuming that there is a localised target.

Actually , I am not assuming a localized target.
I am assuming they are targetting the world.

The Chinese Smart Phones have been shown to ship with spyware and malware installed , now these servers with built-in hardware remote backdoors.
China is systematically and deliberately building backdoors into every product. And we are letting them do it, and not calling them out.

Quote
Therefore you have to work on the assumption that ANY motherboard made in China is potentially compromised.

Based on the evidence, we have to assume EVERY piece of electronics from Red China is spyware until proven otherwise.

Quote
So what to do?

The only real solution is to restore localized international manufacturing.
That is the only way to ensure what is actually in the product .

Remeber history, or be doomed to repeat it:
- Remember the Major Name Brand (from china) pet foods poisoned with melamine to increase "tested protein"?
- Remember the Major Name Brand toothpoaste from china that was laced with anitfreeze because it was the cheapest sweetener?
- Even now, mainland Chinese citizens still flock to Hongkong and Shanghai to buy commercial Western made Baby Formula by the pallet
     because Chinese Baby Formula is tainted and cannot be trusted.
- At the Bejing Olympics, athletes were banned from eating local Chinese food because they were so full of chemicals, drugs and hormones that the
     athletes would fail the drug screening tests.

- RIGHT NOW there is an international shortage of common Blood Pressure Rx medicine,   ( valsartan, losatran and irbersartan) 
    the recall began in mid 2018 due to The impurity, known as NDEA, was found in the drug's key ingredient made by Zhejiang Huahai Pharmaceutical Co. in China.
    the base drug is used worldwide by EVERY Pharma manufacturor and Zhejiang Huahai Pharmaceutical is the ONLY source for the base medicatiuon.

    NDEA is used to make rocket fuel and can also be a created through certain chemical reactions and as a byproduct of industrial processes.

https://www.webmd.com/drug-medication/news/20181113/losartan-latest-bp-drug-recalled-for-contamination (https://www.webmd.com/drug-medication/news/20181113/losartan-latest-bp-drug-recalled-for-contamination)
https://www.webmd.com/hypertension-high-blood-pressure/valsartan-losatran-bp-med-recalls-2018-19 (https://www.webmd.com/hypertension-high-blood-pressure/valsartan-losatran-bp-med-recalls-2018-19)
http://fortune.com/2019/02/27/fda-blood-pressure-medication-recall-list-losartan-2019/ (http://fortune.com/2019/02/27/fda-blood-pressure-medication-recall-list-losartan-2019/)
http://fortune.com/2019/02/13/cancer-causing-chemicals-contaminated-heart-medicine-cardiovascular-drugs-fda/ (http://fortune.com/2019/02/13/cancer-causing-chemicals-contaminated-heart-medicine-cardiovascular-drugs-fda/)


The Big Corporations outsourced all manufacturing to maximize  profit.
which means the technology was "given away" as well .

That also meant that good technical jobs, including product design , product engineering, QA, technical security, etc are all gone.
Which means none of those jobs (including AeroSpace!!!! ) are available in the Western Hemisphere, and damn few in EU.
Which means the current and next generations will not have jobs that pay enough to support buying anything but food and rent

which means the Consumer-driven economy is slowly collapsing upon itself. - nobody can afford to buy the products! ( except the new chinese middle class)

even now, kids with EE an IT degrees are moving to India because that's where the jobs are.

yes it will "increase costs".  But perhaps it will be back to a more "normal state".
instead of $20 DVD players and $80 TVs sold in grocery stores that break after a year.
we should be able to have $100 players & electronics that last 5 years.



I would love to, but the entire outsourcing debacle means there will be little or no  Aerospace Engineering
going on in the western world , which is actually why I put this rant here.

You yourself have found no jobs in the US even tho you are overqualified for those few available.

We have seen the Boeing 737 grounded because the Aerospace technoweenies never tested the "smart software" enough
and Boeing Management refused to fix it even when it was thrown in their faces by the pilots.
Similar problems occurred with the Airbus 320 family.

When I worked for Honeywell and Sperry, we built triple redundancy in all MODULES of  fly-by-wire systems, with extensive POST (Power On Self Test)
and Background running BIT ( Built In Test) software, which included 3-way voting and shutdown of an "out-of-spec" module, switchover to
dual-redundancy and a RED FLAG to replace the module upon landing.  That software was then leveraged into Ground based STD (Self Test and Diagnostic) software,
and FAT  (Factory Acceptance Test) software that could be run any time the plane was hangered.

The Acceptance Testing and Selloff software/ firmware  was run on EVERY box prior to shipment, in a "shake and bake" temperature and vibration test stand
and a factory or DOD rep (or both) witnessed and signed off on the whole thing. The checklist was a book several hundred pages long, and we generated a
printout from the test stand detailing the serial numbers of the chasis, the serial numbers of the circuit cards, testers and witnesses names, and chip lot numbers
so we had a permanent paper archive as well as electronic record. .

Q/A  of the development process was done IN PARALLEL with flight system and test software, hardware, and firmware development by a completely
independant Q/A team that answered to a different VP.

Q/A also did destructive testing, and failure analysis of all failed components . They had an electron microscope and disected the chips. Almost
all failures were due to failed/blown internal chip paths. Q/A could  tell which chip paths had failed and how. They were so good they were able to determine
"what " caused a path failure with a greater than 90 % certainty. Most were due to ESD (Electrostatic discharge).  Some were pre-installation, some
after the chip had been wave-soldered to the board.  Q/A were even able to determine what kind of ESD - ie: static from a 1 foot piece of scotch tape
pealed off the roll next to the componant blew a different hole than static from an ungrounded worker touching a board.

Q/A also took samples from every chip lot and dissected them. They used Xrays to examine the layers and they compared the actual chip guts to the
archived design LSI layers matrixes.  One time,  they found some ass-hat had etched their initials into a corner. The ass-hat was pilloried, held up as an
example of STOOPID and that batch of chips destroyed.

It was pricey, but as I told folks we were responsible to keep airplanes from falling out of the sky.

This included the 727, first gen 737, 747 and first gen 767 as well as the  AV8B, F4-G, F14, F15, F16 and first FA-18, and several black programs. 

Guess what?

Neither Honeywell, Sperry, Boeing or McDoug  do that anymore . Their LSI chip fab plants as wel as TI's and Motorolla's and Intel's plants have been closed
and outsourced to Asia.

That's the Aero part.

The Space part is just as bleak. The available jobs suck, they are mainly paper-pushing "project manager" jobs meant to give lip service to
Western oversight of Asian contractors.  and commercial endevours are the only thing going forward.
Since Asia manufactures all electronics,  I actually expect backdoor hardware to be in all commercially launched satellites.

I actually have to appologise for sounding so bleak, but this is actually the same pattern that followed technology at the turn of the 1890-1920 era.
change the names and it's the same. The huge rail, telegraph, and  oil corporations dominated the country at the cost of the common folk and pollution.
Jobs were outsourced from EU for "cheap labor" and sweatshops and factor mill jobs and mining jobs were dangerous and killing workers, and
child labor was the norm.

The FDA did not exist yet, so poison was sold as medicine, and COCAIN was the active ingrediant in Coca Cola.
Tainted and rotten or adulterated food was common.

So now it's come full circle again, and we just have to fix it.

My basic advice is go live where the jobs are.
If automation is replacing your job, get training and a job the build and fix the automation.

If you want to work in Aerospace, figure out a "niche" that can't be outsourced.

Tesla and Musk and Bezos spend millions on PR to look good, but they are legends in their own minds. They are working their people to death,
workers hate them, they are all constantly trying to get around laws and regulations.

space rant over, more on next post

yhs
prof realist

a realist is one of those grumpy barstiches
that  see things as they really are
instead of how we tell them.

oops I lied, one last bit

Quote
And also remember: what's good for the goose is good for the gander. Now that we know, the US can retaliate in kind, regularly buying motherboards and analysing them for reverse hacking. It's something that is best done without announcing your intentions. These safety checks should be routine by now. The "scandal"  today is all about corporations being too innocent a decade ago to realise they were used as pawns.

Actually the West started it when they weaponized a virus to cause ultra-centrifuges that were in extremely specific facilities to destroy themselves .

And analyzing  purchased componants has 2 drawbacks
- firstly destroys the ability for the corporation to claim "Plausible deniability"
- costs money that was saved by outsourcing and we see from the article that management is not willing to jeapordize the huge potential market called China

Quote
These safety checks should be routine by now. The "scandal"  today is all about corporations being too innocent a decade ago to realise they were used as pawns.

actually, they were not innocent "decades ago". People like me were regularly reporting up the food
chain on hacks, attacks, and obviously stolen IP (intellectual properties) .

NOBODY WANTED TO HEAR IT
one guy had to work for over a year to convince any govt agency that their univeristy computer had been hacked and was
being used to access the (then ) darpanet to steal secrets.

We were told "not your job, sit down and shut up , or find another job in another company"

Quote
And what makes you feel that this could not be exploited by individual actors as well? Google, Amazon, Apple can perform a bit of the same snooping of they choose to. Even individual actors strategically infiltrating a company can do it we can point the finger to China, but you may be dealing with a Stand Alone Complex, where multiple unrelated actors across the world are doing the same, leading you to believe that there is one boogeyman when in fact it's many.

I am not so stupid as to believe there is only one boogeyman. I spent far too long in the biz
with electronic security as a "side job". I have a huge list of doco regarding the sins of
Amzon, Google, Yahoo, and the individual 11 ( I saw what you did there!) individual Internet
Service Providers.

"we" are actually being "watched" constantly via the web. PM me if you care to chat offline....

My point is that this is one of the first large scale massive built-in hardware backdoors ever
perpetrated, GLOABALLY, even bigger than the so-called "security holes" in the internet ready devices.

AND THEY KEPT IT QUIET!

yhs
the grumpy realist

And now back to Aerospace


So, prof grumpy, can you summarize ANY of this?

glad you asked!

basically, it looks like the U.S. and Russia are virtually dead as far as Manned Space
exploration goes. All I see is satellites, exploratory remote thingies, and maintaining
big rockets like the Vostok

India, Japan, and China are definitely moving forward with some sort of plans.
It appears as tho japan is looking into mining asteroids, but I cannot begin
to guess what India and China are doing beyond Earth Orbit stuff, some of it
will probably be weaponized.

what about the Aerospace Commercial Sector?



Ford Aerospace was bought by Loral in 1990; all they did was build missles

Sperry Aerospace bcame part of Unisys and was then sold to Honeywell Aerospace ~
Honeywell Aerospace is ramping down and closing facilities

Northrop Grumman Aerospace and defense company still exists, but is mainly "defense"

McDonnell Douglas was bought by Boeing
North American Rockwell ( ie: Space Shuttle) was bought by Boeing

The U.S. manned space flight programs are essential dead. During the three decades of operation,
various follow-on and replacements for the STS Space Shuttle were partially developed but not
finished.

NASA is now a place to get a job doing "satellite" stuff.

----------------------------------------
NASA employees earn $62,500 annually on average, or $30 per hour,
which is 2% higher than the national salary average of $61,000 per year.
According to our data, the highest paying job at NASA is a Lead Engineer
at $126,000 annually while the lowest paying job at NASA is a Student
Researcher at $21,000 annually.


Boeing still builds planes but very little "space" and  is *still* doing "staff up and layoff"
and you saw my opinion earlier.
-------------------------------------------

The typical Boeing Engineer salary is $89,000. Engineer salaries at Boeing can range from
$55,880 - $158,413.

--------------------------------------------

airbus still builds planes, mainly EU based

Salaries at Airbus range from an average of $47,943 to $147,776 a year. Airbus employees with the
job title Vice President (VP) of Product Development make the most with an average annual salary of $199,230,

--------------------------------------------

Lockheed Martin is like Boeing

An Entry-Level Aerospace Engineer at Lockheed Martin Corp earns an average salary of $64,921 per year.


--------------------------------------------

SPACEX is a "maybe" and one of the few "space" places left.

But until "somebody" builds a large scale permanent manned orbital platform
bigger and more robust more self-sufficient than the EU space station, they have no place to fly to.

------------------------------------------
How much do SpaceX employees make?
The average SpaceX salary ranges from approximately $42,441 per year for Laser Technician
to  $111,709 per year for "Engineer. "

When factoring in bonuses and additional compensation, a Mechanical Engineer
at SpaceX can expect to make an average total pay of  $90,000

Average SpaceX hourly pay ranges from approximately
$18.80 per hour for Welder to $31.00 per hour for Inspector.
-------------------------------------------


but be aware, Musk is a visionary and that can also mean "psycho"

"real people" hated working for visionary Saint Steve Jobs at apple, his behavior can
be described as schizophrenic, just like Tesla.

yhs
prof grumpy realist

Don't talk to me about SpaceX. It took all but 45 minutes for them to send me an email rejecting my application. Clearly they are a boutique company who don't really follow normal hiring procedures.

On Boeing and Airbus. Please note the new frontier is short haul and smaller passenger jets. The jumbo jet market is sputtering. The A380 is being discontinued in 2020, and Boeing has hinted the old venerable 747 might follow. Last summer Boeing, embattled and bleeding for its spat with Bombardier ended up buying or merging (I don't know which) with the commercial division of Embraer. This after Bombardier won the unfair competition lawsuit last year and by Winter they had merged their commercial division with Airbus, as a workaround to US rules on foreign government aid.

The battle is now Boeing / Embraer in Brazil vs. Airbus / Bombardier in Canada and Mexico. Like I wrote before, Dr. David Dolling former Chairman of the Aerospace Engineering and Engineering Mechanics Dept at the University of Texas at Austin (and my Hypersonic Fluid Dynamics professor) told me about one year ago that Mexico is graduating MORE Aerospace engineers in Mexico than the whole of the United States.

As an aside, I wrote somewhere else that according to Forbes, several years ago, Mexico produces about 1/2 of the number of engineers who graduate in the US annually. The US is currently #2 at over 200 k engineering graduates per year and Mexico is at over 100k ahead of France. The number one country in graduating engineers is Russia, with over 400 K. There's perfectly good reasons for those numbers. And if its not a military "cold war" or political response (like Iran), then it has to be an economic response to domestic demand or industry migration from the First World.


What it means is that American educated Mexican and Brazilian students have gone back to their respective countries to teach a new generation of engineers.  I could see the Brazilian students in the 1990s and 2000s at Austin. Some like a Japanese-Brazilian were my friends. He got a PhD and returned to Brazil, where his parents are wealthy.. There's no place for him to go other than academia or Embraer.

Same for India. It's full of institutes teaching Aerospace Engineering, full with graduates from MIT and Caltech serving as professors - you can tell if you come to any of our AIAA meetings or read our technical papers. Those new engineers in Mexico, last I checked 5 years ago were perfectly happy earning $40000 at General Electric designing aircraft engines. This process is not something you can reverse. What you can do, however, is join the new generation of engineers.

I would have liked to follow my career and have grown a family in the US. But due to real life problems like death, family business and bankruptcy I was held back. Perhaps national pride would have still kept me here. But national pride for me is now useless; it died when I was attacked one and a half years ago in the street by people telling me that the Great Ompaloompa in Washington would "take care of me and my people." And by "care" I don't mean in a good way.

That is when I made my decision. The world is changing and so must I. I feel sorry for America, but America needs to decide who they want to be. What I see is that they don't want to be an immigrant nation any longer. Thereby stopping the influx of fresh blood that made this the most dynamic nation on Earth. If you take out all immigrants the birth rate will fall below 1.2 children per family, and the US population will start to decline, like most other developed countries. The "consumer economy" is already blowing up in our faces, like you implied - and everywhere in the First World. So maybe being the wealthiest is not all that is cracked up to be, right? But the current path I see is self-destructive. 30—40% of the population is far too many voices against what what I thought we were all about, and that is a grass roots movement.

Alas, I'm too old to contemplate that change. If the next 25 years pass as fast as the last 25, in the blink of an eye, I will be in my 70s.. It's not like I'm going to hang a poster of El Ché Guevara in my bedroom, raise my left fist and scream "for the people" to the tune of "Sleep Now in the Fire" by Rage Against the Machine, and go fight the "Fascists" in the streets of America. To begin with, that's not my political ideology, and I'm too old for that. I'm very much a pro-European culturally and politically I was so inclined in Mexico, but that is something my fellow Americans don't understand, because they just don't know who we are.

I'm poor and old but still young looking and not old enough to retire, so I have to keep moving. My family descends from people who came from France Italy and Spain and they didn't hesitate to move when it was necessary to do so. Now it's my turn. I have to do the same again. Others in my family are Native to Mexico. They survived the conquest. So I will do that. I'll move and I will survive.

My offer is this: anyone who wants to come to Latin America with an open mind can do so and expect to see the re-emergence of this industry. But first you must free your mind from misconceptions, and be willing to suffer a little by way of personal comforts.

Rage Against The Machine - Sleep Now in the Fire (from The Battle Of Mexico City) (http://youtube.com/watch?v=w211KOQ5BMI#)

Greetings My Dear J and Friends

firstly I must appologise , I fear I fell into taking certain things a tish personally, when I misread the pronoun  "you" to mean "me".
In order to avoid that I deliberately  try to use "one must this and that"  vs "you must this and that" .....

I think in the two decades of  the 21st century the U.S. has  become stupid and complacent. Somehow "those in charge" stopped listening
to the very experts that they hired.

I fear the Great Morons worldwide have beat the drum of "national pride" (facsim) and brought the scum up from the pond bottom, to the greater
detriment of everyone. As you said, each person needs to decide for themselves how best to deal with it, and many are leaving or on the cusp of it.

J, I must have missed some of your posts... I hope you can make the move and transition to Mexico succesfully! Cost of Living is certainly less.
Ford and several other major players built quite a few manufacturing facilities in Mexico, and if you can land a spot with GE down there I
believe you would be in fat city!

I have many colleagues in Mexico City, with the Former Sun Micro, Oracle Corp, IBM etc, and they have been rather succesful and living well on
$30k-$40k !  It has been my limited experience in the past that technical management in Mexico City doesn't care about age as much as ability .

Since the US and Russia are passing the spaceflight torch along, I will continue to actively monitor and cheer on the Aerospace successes of  others!

yhs
prof marvel

Quote from: Prof Marvel on April 15, 2019, 06:59:03 AM
Greetings My Dear J and Friends

firstly I must appologise , I fear I fell into taking certain things a tish personally, when I misread the pronoun  "you" to mean "me".
In order to avoid that I deliberately  try to use "one must this and that"  vs "you must this and that" .....

I think in the two decades of  the 21st century the U.S. has  become stupid and complacent. Somehow "those in charge" stopped listening
to the very experts that they hired.

I fear the Great Morons worldwide have beat the drum of "national pride" (facsim) and brought the scum up from the pond bottom, to the greater
detriment of everyone. As you said, each person needs to decide for themselves how best to deal with it, and many are leaving or on the cusp of it.

J, I must have missed some of your posts... I hope you can make the move and transition to Mexico succesfully! Cost of Living is certainly less.
Ford and several other major players built quite a few manufacturing facilities in Mexico, and if you can land a spot with GE down there I
believe you would be in fat city!

I have many colleagues in Mexico City, with the Former Sun Micro, Oracle Corp, IBM etc, and they have been rather succesful and living well on
$30k-$40k !  It has been my limited experience in the past that technical management in Mexico City doesn't care about age as much as ability .

Since the US and Russia are passing the spaceflight torch along, I will continue to actively monitor and cheer on the Aerospace successes of  others!

yhs
prof marvel

Thank you! It's like pioneers in the old west, "Mexico or Bust."
I hope you're right about the age thing in hiring. But I'm not holding my breath, I know at my age I'm less than desirable, and Mexico is a country where the majority are young! But honestly, I'd be happy just helping the Aerospace students in any capacity and using my English and Technical skills simultaneously.

I'll start by creating an income that is independent of physical location (internet based) before even trying to move! I need very little to live on. And in Mexico even less.

Valentin Privalov for MIG-17, June 4, 1965. Novosibirsk. This is a photo montage, even though the flight was.

(https://www.snopes.com/tachyon/2017/07/russia-pilot.jpg?resize=768,511)

So the suspicion is (based on newspaper reports) that the flight did happen but the photo itself is  a hoax with very dramatic imagery, created by someone to post in a newspaper. The real stunt would not have looked so dramatic. http://hoaxes.org/weblog/comments/soviet_pilot_flies_under_bridge (http://hoaxes.org/weblog/comments/soviet_pilot_flies_under_bridge)

Hot from the grapevine (well actually a couple of weeks old)

1: Mexico's National Autonomous University UNAM, announced the start of their own Aerospace Engineering program, I imagine splitting the degree away from the Mechanical Engineering department. This brings the total number of colleges and universities that offer a dedicated Aerospace Engineering program to 12. Last I heard, according to David Dolling, former University of Texas ASE - EM chairman the numbers of Mexican Aerospace graduates has exceeded the same figure for American Universities. In June of last year, UNAM's "High Technology Unit" a graduate department, had signed into the International Astronatics Federation

https://www.gaceta.unam.mx/la-uat-a-la-federacion-internacional-de-astronautica/ (https://www.gaceta.unam.mx/la-uat-a-la-federacion-internacional-de-astronautica/)


However, with the year-old administration of Mexican President A.Manuel López Obrador, "AMLO," it remains to be seen what progress will be made in the aerospace industry, for his administration is somewhat anti-business and he's focused inward toward addressing income disparity in Mexico and has spearheaded a campaign against "Neo-Liberal Economics" which is political jargon for "unbridled capitalism with no government control." The political climate has caused foreign investors to to hold making new inroads into Mexican industry, so hopefully this doesn't result in a glut of engineering graduates unable to find work.


2. In recognition of Mexico's emerging Aerospace industry (design and manufacture of satellites, assembly of executive aircraft, turbine engine design,  commercial aviation electrical systems), Russia's Roscomos space agency signed a cooperation treaty with Mexico's EAS space agency. The treaty will focus on space technology and more specifically satellite applications related to meteorology, ground surveillance for farming, mining and such, and natural disaster warning systems.

https://www.gob.mx/aem/prensa/sumaran-esfuerzos-en-proyectos-espaciales-mexico-y-rusia-230582 (https://www.gob.mx/aem/prensa/sumaran-esfuerzos-en-proyectos-espaciales-mexico-y-rusia-230582)


Naturally this is a good thing for Mexico and Russia, but not so good for the US. In the past, during the  Cold War, the US' NASA and Mexico's EAS cooperated in all matters of space exploration and technology, but the current political climate between the United States and Mexico is not looking conducive to cooperation (it gives me the impression that only the private US aerospace industry seems to be fully aware of and exploiting Mexican potential). Hence its not a surprise that new doors are opening to other countries' government programs. Something to think about (and I'll stay out of politics after this last sentence).

Mexico's space agency, EAS is much older than people realize. For example, the first Mexican Astronaut was (Payload Specialist , Engineer) Rodolfo Neri-Vela, who flew in 1985 to deliver the second Mexican satellite, "Morelos II" aboard Space Shuttle Mission STS-61B, in 1985.



https://en.m.wikipedia.org/wiki/Rodolfo_Neri_Vela (https://en.m.wikipedia.org/wiki/Rodolfo_Neri_Vela)
https://en.m.wikipedia.org/wiki/Morelos_Satellite_System (https://en.m.wikipedia.org/wiki/Morelos_Satellite_System)

In honor and memory of Влади́мир Миха́йлович Комаро́в (Vladimir Mikhaylovich Komarov)

16 March 1927 To 24 April 1967.

Soviet test pilot, aerospace engineer, and cosmonaut. In October 1964, he commanded Voskhod 1, the first spaceflight to carry more than one crew member. He became the first Soviet cosmonaut to fly in space twice when he was selected as the solo pilot of Soyuz 1, its first crewed test flight. A parachute failure caused his Soyuz capsule to crash into the ground after re-entry on 24 April 1967, making him the first human to die in a space flight.

On 26 April 1967, Komarov was given a state funeral in Moscow, and his ashes were interred in the Kremlin Wall Necropolis at Red Square. The American astronauts requested the Soviet government to allow a representative to attend, but were turned down.

I turn over a glass for this heroic Space Pioneer.

Yhs
Prof Marvel

QuoteIn honor and memory of Влади́мир Миха́йлович Комаро́в (Vladimir Mikhaylovich Komarov)
I turn over a glass for this heroic Space Pioneer.

Here - Here!

Ooops. The last remnant of the Boeing/Bombardier/Airbus/Embraer Saga ends rather unceremoniously...

If you recall, at the start of the current US administration, Boeing had filed a trade complaint and sued Canada's Bombardier in trade court over their contract to supply Delta Airlines with their C-Series 100 passenger jet. The pretext was that an N. Irish factory which made wing parts for Bombardier was getting sunsidies from the UK government. In reality Boeing wanted to push 737 jets to Delta, but Delta needed smaller planes. Canada responded by cancelling a $6 billion USD order of CF-18s made by Boeing, by raising a law that stated that Canadian companies can't do business with entities that harm Canadian interests (this was still before trade wars erupted globally between the US and other countries).



Then as one year rolled by and trade wars heated up, Bombardier apparently was cash strapped (which I understand now has always been normal for that company), and being scared by Boeing's aggression decided to offer their C-Series segment of the business to Airbus. Before Bombardier even found out that they had won their case in US and international trade courts against Boeing, Airbus had already snapped up the C-Series, because as it happens Airbus have factories in the us. Under US law even if you install *one screw* in American soil, that airplane becomes "American-made" - the perfect circumvention to the trade dispute. The losers in that deal were Mexico, really who already had been working on Bombardier's Learjet assembly for many years and now were building electrical systems for the Bombardier C-Series - the electrical system jobs moved to Airbus plants in the State of Georgia in the US.

In July of last year Delta airlines, an American company announced they would no longer purchase Boeing aicraft.
The 737 was one of their favorite planes. Gee, I wonder why? Ever heard of not suing your customers?
https://airwaysmag.com/airlines/delta-receives-last-boeing-future-all-airbus/ (https://airwaysmag.com/airlines/delta-receives-last-boeing-future-all-airbus/)


Panicked, Boeing sped up a proposed deal to buy a majority stake (80%) of Brazilian company (and major 100 passenger jet market competitor) Embraer, who makes the very succesful E-195, the direct competition to the C-Series (now known as Airbus 220), and presumably the # 1 rivalry in the 100 passenger market (at least in the Americas), and that's not counting their military tanker/cargo plane C-390 Millenium. The idea was to compete against Airbus by taking advantage of lower wages for engineers in Brazil, and turn the civil part of Embraer into "Boeing Brazil," or something like that.


Well guess what? Besides Bombardier announcing their late offer of Learjet to Textron this February (thus abandoning all aircraft manufacture - not related to COVID at all), Boeing just cancelled their merger deal with Embraer (this time probably because of COVID). The breakup was ugly, irreverent and callous on Boeing's side, with the dispute between Boeing and Embraer going to arbitration

https://www.bjtonline.com/business-jet-news/boeing-embraer-saga-leaves-sour-taste-in-brazil (https://www.bjtonline.com/business-jet-news/boeing-embraer-saga-leaves-sour-taste-in-brazil)

The losers now? Everyone. Brazil gets stuck with a non-payment of a $100 million termination fee (in arbitration now). Bombardier is slowly extinguishing, Canada loses a homegrown aerospace company and a chance at big markets, Mexico already lost the C-Series jobs and might even lose all Learjet business to Textron in Texas (assuming that Textron wants to go through with the deal - unlikely at the moment - maybe the Mexican factories are just closed).

Most passenger jets , about 2/3 worldwide are parked now anyways thanks to the COVID 19 pandemic.

https://en.wikipedia.org/wiki/Impact_of_the_COVID-19_pandemic_on_aviation (https://en.wikipedia.org/wiki/Impact_of_the_COVID-19_pandemic_on_aviation)

https://www.bloomberg.com/news/features/2020-04-16/coronavirus-travel-what-happens-to-planes-grounded-by-covid-19 (https://www.bloomberg.com/news/features/2020-04-16/coronavirus-travel-what-happens-to-planes-grounded-by-covid-19)

Airbus loses too, but they dominate the market a bit more now on account of them holding the A220...

It makes you wonder if all those lawsuits were worth the paper they were printed on. Don't you think?

This is Time Magazine's live coverage of the launch of the manned SpaceX Crew Dragon spacecraft for the Demo-2 / Crew Demo 2 mission. Just tune in, it's T-2 hrs away from right now! This marks the US' return to manned space missions after a whole decade after the Space Shuttle was mothballed.

SpaceX & NASA Launch U.S. Astronauts To Space | TIME (http://youtube.com/watch?feature=youtu.be&v=9NsbsLV6hX4#)

Almost unbelievable.
I cried.... really, I wept when that rocket lifted off, and then when the first stage separated.
It's been so very, very long in coming, the return to true space exploration. We should have had colonies in the moon by now.
Thank God for visionaries like Elon Musk.

Quote from: Deimos on May 30, 2020, 10:55:26 PM
Almost unbelievable.
I cried.... really, I wept when that rocket lifted off, and then when the first stage separated.
It's been so very, very long in coming, the return to true space exploration. We should have had colonies in the moon by now.
Thank God for visionaries like Elon Musk.

I can't say that I had the same reaction, but many people did, including my high school buddy who just texted me afteriI sent him a link to the live feed from NASA. He's a tenured college professor teaching history in Mexico City, with whom I watched the first launch of the Space Shuttle Columbia when we were kids. As someone who was inspired into the degree by the 1981 launch of Space Shuttle Columbia, I have a special connection to manned space exploration, even though my soul belonged to Aeronautical flight. The Space Shuttle was unique it combined both disciplines of aeronautics and space flight, so it immediately called my attention. My entire life was filled with the pursuit to understand that machine. But by the time that I finally graduated in 97 I became aware of my capacity for research and I moved from a focus in industry to one in academia.

In all honesty I was not prepared to fully answer the question "how does it work" until two years later in 1999, at which point I had covered everything from atmospheric re-entry through propulsion (aerothermodynamics, hypersonic flight, combustion, etc, etc). Had I not been pulled in that academic direction, I might actually have gone to industry and have caught up with the last few years of the program, in God knows what capacity. Instead, the computational side of hypersonic aerodynamics intensely interested me, and I got to attend several presentations by Lockheed Martin on the X-33 demonstrator (which was a flop - I talk about it somewhere in this thread) during the annual AIAA conferences.

What I did get to do related to the manned space program was have a few Aerospace legends as tutors. The most important perhaps being my orbital mechanics instructor, Hans Mark, a theoretical physicist assigned to be the US Army liaison to Werner Von Braun and his technical team (because he spoke German, as a German migrant to the US and was a physicist by education). Hans Mark was also a former Secretary of the Air Force (1977—79) and Deputy Administrator of NASA (1981-84) during the first Space Shuttle missions.

Anyhow, I think my historian friend was far more exited about the launch than I was. Perhaps back then we were more innocent as kids and the future was so much more brilliant. I did try my hand at joining SpaceX, but my application was rejected in the most irreverent way after only 45 minutes after filing it! Elon Musk (has a degree in Physics) is a visionary, but like all visionaries he's a bit eccentric, shall we say? I used to think that Burt Rutan was a narcissistic weirdo, but Mr. Musk takes the cake. I still think that the world will immensely benefit from Elon Musk's visionary life, though.

My Dad worked for McDonnell-Douglas his whole life as an EE...designing cockpits for fighters and other "things" (keep reading).
He began working for them in 1950 when it was still McDonnell Aircraft, before they acquired Douglas Aircraft in 1967.

See the Wikipedia entry here (https://en.wikipedia.org/wiki/McDonnell_Douglas) and scroll down to Military Aircraft.
If it was built between 1950 and 1980 (the year he died) he worked on it.

He also worked on  space projects Mercury, Gemini and Skylab... was always bringing home photos, drawings , small mockup pieces. Was that legal?...I dunno ...I wasn't even 10 at the time and didn't bother about the ethics of such matters.  ;)

Come 20 July 1969 I was glued to the telly like everyone else around the world.

Except unlike a lot of people, most people in fact, I wasn't awed.  I had been reading SF for 5 years by that time.
All I could think of was "It's about time! Next on the agenda: colonization!"

I really thought that by the time I was in my 50s or 60s one would be able to take a trip to the moon.
Maybe it would be exorbitantly (pun intended) expensive, but at least it would be possible.
But it never happened.
So you may well believe it when I said I wept at a successful Falcon 9 flight.

(And, yes, you don't have to like someone, who may be a first class jerk, to appreciate his genius or vision.)

In remembrance of Chuck Yeager, RIP (February 13, 1923 – December 7, 2020), I'm posting this Smithsonian documentary on the first supersonic flight.

The Sound Barrier - Bell X-1 / Documentary (http://youtube.com/watch?v=li6UV-KGe7E#)

Good afternoon. I'm somewhat unfamiliar with the locale. However, Miranda, acting as guide and via the following post...

Quote from: Miranda.T on January 04, 2021, 11:56:27 AM
My goodness, there is a wealth of technical detail to pour over there! May I humbly suggest you add a link to these papers within the metaphysical/meta-clubs/The Guild of Icarus thread so that your fellow engineers here can be aware of, peruse and engage in discourse around their content (whilst enjoying a fine brandy, of course).

Yours,
Miranda.

...directed me to this thread and suggested that I post my particulars. Specifically, Miranda thought you might be interested in the following flying machine which I post for your perusal.

https://gordonhart.substack.com/p/airship-1897

(https://cdn.substack.com/image/fetch/w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fbucketeer-e05bbc84-baa3-437e-9518-adb32be77984.s3.amazonaws.com%2Fpublic%2Fimages%2F2a29d987-7c02-40fe-98d8-adc8b4bdb358_425x550.png)

Quote from: Triztrooper on January 04, 2021, 02:26:26 PM
Good afternoon. I'm somewhat unfamiliar with the locale. However, Miranda, acting as guide and via the following post...

Quote from: Miranda.T on January 04, 2021, 11:56:27 AM
My goodness, there is a wealth of technical detail to pour over there! May I humbly suggest you add a link to these papers within the metaphysical/meta-clubs/The Guild of Icarus thread so that your fellow engineers here can be aware of, peruse and engage in discourse around their content (whilst enjoying a fine brandy, of course).

Yours,
Miranda.

...directed me to this thread and suggested that I post my particulars. Specifically, Miranda thought you might be interested in the following flying machine which I post for your perusal.

https://gordonhart.substack.com/p/airship-1897

(https://cdn.substack.com/image/fetch/w_1456,c_limit,f_auto,q_auto:good,fl_progressive:steep/https%3A%2F%2Fbucketeer-e05bbc84-baa3-437e-9518-adb32be77984.s3.amazonaws.com%2Fpublic%2Fimages%2F2a29d987-7c02-40fe-98d8-adc8b4bdb358_425x550.png)

And an interesting machine it is! This very much looks like the developments and diagrams that I had in mind but for an even earlier time period in the 19th C. to allow for the Franco-American Aerial War to happen in my tentative novel "The Valkyrie and the Eagle." Thank you for posting!

I don't post here very often, and much less on the subjecty of sailing. But the last time I kept with sailing technology it was the late 1980s and I was a young lad starting college in San Diego, which is what introduced me to the America's Cup and that disastrous international scandal between New Zealand and the United States. The issue being lawsuits back and forth over what kind of technology could be used to meet the race requirements, and after a bitter complaint from the USA over certain technology used by New Zealand, the Americans decided to retaliate by bringing a rigid-sail catamaran as allowed by the loopholes in the vaguely defined rules of the race...

https://en.wikipedia.org/wiki/1988_America%27s_Cup (https://en.wikipedia.org/wiki/1988_America%27s_Cup)


But after not paying attention to the sailing technology over the last 3 decades, I saw today on NBC Sports Network the latest race beween the UK and Italy in the 2021 Prada Cup which is taking place between January and February of this year (currently ongoing).



What I saw gobsmacked me. The easiest description of the craft is a racing craft with dual articulated hydrofoils, each *with functional ailerons*, on a hull that acts as a lifting body (airfoil cross-section), naturally a wing plus a sail, and oh yes, the thing can cruise up to 45 knots and turn "on a dime" to tack using said ailerons and rudder. No engine of any kind, just the wind, and the hull barely gets to touch the water.  So there's so much going on that I'm going to post one of the races, and let you marvel at these craft.

Full Race Replay | Day 1 | PRADA America's Cup World Series Auckland, NZ (http://www.youtube.com/watch?v=ne-covgb3ao#)

I remember when Australia II had its legendary winged keel and that was regarded as a such a novel concept. Certainly, the power of the wind can really move you, whatever your craft

Class 5 Land yachts racing and fails on 90 Mile Beach (http://www.youtube.com/watch?v=LRTahy3OiuU#)

Click on link to go to the live video feed

https://www.nasa.gov/nasalive (https://www.nasa.gov/nasalive)

Today's SpaceX' Starship SN-10 flight test to 10 km altitude (1/8th altitude of von Karman Line, the to "edge of space")

Starship | SN10 | High-Altitude Flight Test (http://youtube.com/watch?v=ODY6JWzS8WU#)

And what they forgot to show you at the end  ;D

Boom! SpaceX Starship SN10 explodes shortly after landing (http://youtube.com/watch?v=hzhP3Q5fku8#)

Every "Bang!" gets closer to "The Real Thing". The news said it was a planned "Bang!" - is this so? I'd rather a planned bang on earth than an unplanned bang in space!

Quote from: Banfili on March 04, 2021, 10:46:37 PM
Every "Bang!" gets closer to "The Real Thing". The news said it was a planned "Bang!" - is this so? I'd rather a planned bang on earth than an unplanned bang in space!

Not planned. They had a CH₄ fuel leak after shutting off the engines. I don't particularly like that big skirt they have around the engines. Gases can be trapped in there. Most byproducts of combustion around the craft after shutting the engines are in intermediary chemical reactions (highly reactive radicals and unfinished combustion compounds, and usually poisonous), which is why even for a hydrogen+oxygen engine like the Space Shuttle, you can't be close for some time after a firing test (there's like 16 intermediary steps between hydrogen + oxygen and water molecules when you burn hydrogen very fast. The only time you go from hydrogen to water cleanly is in hydrogen fuel cells, literally assembling molecule by molecule slowly in aqueous solution - fast hydrogen combustion is very dirty).

Quote from: J. Wilhelm on March 04, 2021, 11:37:08 PM

Code Select Expand

Quote from: Banfili on March 04, 2021, 10:46:37 PM
Every "Bang!" gets closer to "The Real Thing". The news said it was a planned "Bang!" - is this so? I'd rather a planned bang on earth than an unplanned bang in space!

Not planned. They had a CH₄ fuel leak after shutting off the engines. I don't particularly like that big skirt they have around the engines. Gases can be trapped in there. Most byproducts of combustion around the craft after shutting the engines are in intermediary chemical reactions (highly reactive radicals and unfinished combustion compounds, and usually poisonous), which is why even for a hydrogen+oxygen engine like the Space Shuttle, you can't be close for some time after a firing test (there's like 16 intermediary steps between hydrogen + oxygen and water molecules when you burn hydrogen very fast. The only time you go from hydrogen to water cleanly is in hydrogen fuel cells, literally assembling molecule by molecule slowly in aqueous solution - fast hydrogen combustion is very dirty).

I'm glad the launch & flight were successful, anyway. There are obviously some issues, but getting closer with every test. As for the skirt, would vents help, or would they defeat the purpose of the skirt?
The overall design is sort-of an old-fashioned traditional space ship look look, and I like that - it's very comforting that a space ship looks like something out of a science fiction magazine illustration!! I'm reading quite a bit of the more old sci-fi magazine stories at the moment, and although there aren't too many illustrations to go by, some of the cover pictures are grand! Mind you, a lot of the depictions and descriptions of the alien people and creatures are a bit strange!

Quote from: Banfili on March 05, 2021, 05:59:16 AM

Quote from: J. Wilhelm on March 04, 2021, 11:37:08 PM

Code Select Expand

Quote from: Banfili on March 04, 2021, 10:46:37 PM
Every "Bang!" gets closer to "The Real Thing". The news said it was a planned "Bang!" - is this so? I'd rather a planned bang on earth than an unplanned bang in space!

Not planned. They had a CH₄ fuel leak after shutting off the engines. I don't particularly like that big skirt they have around the engines. Gases can be trapped in there. Most byproducts of combustion around the craft after shutting the engines are in intermediary chemical reactions (highly reactive radicals and unfinished combustion compounds, and usually poisonous), which is why even for a hydrogen+oxygen engine like the Space Shuttle, you can't be close for some time after a firing test (there's like 16 intermediary steps between hydrogen + oxygen and water molecules when you burn hydrogen very fast. The only time you go from hydrogen to water cleanly is in hydrogen fuel cells, literally assembling molecule by molecule slowly in aqueous solution - fast hydrogen combustion is very dirty).

I'm glad the launch & flight were successful, anyway. There are obviously some issues, but getting closer with every test. As for the skirt, would vents help, or would they defeat the purpose of the skirt?
The overall design is sort-of an old-fashioned traditional space ship look look, and I like that - it's very comforting that a space ship looks like something out of a science fiction magazine illustration!! I'm reading quite a bit of the more old sci-fi magazine stories at the moment, and although there aren't too many illustrations to go by, some of the cover pictures are grand! Mind you, a lot of the depictions and descriptions of the alien people and creatures are a bit strange!

Vents might help. But if you look at conventional rockets, they don't have skirts. Ever. The bell nozzles are always protruding below the end of the body of the rocket. The closest I can think of is the Soviet Era N1 moon rockets which also used a large number of small engines, but even then, the space under the fuel tank was not so enclosed with a large volume where gasses can accumulate (in my iwn perspective). Even SpaceX' smaller reusable rockets, the smaller Falcon X series, which land in the same fashion, none of them have a skirt around the bell nozzles. Honestly, I don't really know (but do have an idea about) what purpose it serves, whether structural, or otherwise.


One possibility is that it's means as thermal protection for hypersonic re-entry. The Space shuttle has a large spoiler under the aft engines, which serves as both an aerodynamic attitude control device, as well as thermal protection for the engines.


I'm thinking that perhaps the circular skirt is designed to provide protection to the engine nozzle regardless of the axis rotation angle of the rocket when it re-enters the atmosphere. You see, the only thing you have to stop the rocket from rolling about its long axis during atmospheric re-entry are the fin pairs, front and back that each form a "dihedral angle" which is a method to create roll stability in aircraft, At very high altitudes, however, you'll depend on attitude control rockets, because there is very little on the way of aerodynamic forces to help those fins do their job. If the rocket only has that flap in the windward side (belly), and enters the atmosphere "belly up" or "sideways" for whatever reason, the engine nozzles would be unprotected from the plasma flow as the density of the air increases and while the craft stabilizes aerodynamically - I don't know it's a very wild guess on my part, but it's the only thing I can think of.

I understood at the beginning of the project that even with the stainless steel skin, the SN-X rockets would incorporate *some sort* of extra thermal protection system besides the stainless steel skin. But with Musk everything is so mysterious and ever changing and this is such an unconventional rocket. I have not seen any extra thermal protection implemented at all in the SN series of rockets. Quite the contrary, the last time anyone seriously considered metal skins was about 20 years ago with the X-33 Lockheed Martin demonstrator vehicle, which used Inconel slabs bolted over an aluminum mesh around fibreglass tanks. Before the Space Shuttle, steel was considered in the 1960s, during the age of "DynaSoar" lifting bodies, and before that, it was the Silbervogel, a Nazi-Era suborbital bomber design. Metal in general is very difficult to use as a thermal protection system, not only because of the melting temperature, but also because it is chemically reactive with the radical compounds found in the plasma of hypersonic re-entry flows (it literally burns).

I think that this is due to what I heard from Elon Musk, where he was explaining that the re-entry trajectory is unusual in that the vehicle is slowed down as much as possible while staying "above" the atmosphere for as long as possible before "plunging in." The net effect is to reduce the initial airflow speed around the vehicle, which reduces drag (friction) once you plunge in, reducing heat at the skin, and thus allowing for "non-exotic" thermally resistant materials to be used - like stainless steel, as opposed to the Space Shuttle which needs the high performance silica-fibre-based brick and "quilt" system.

I know the Space Shuttle needs to re-enter the atmosphere as quickly as possible to gain positive aerodynamic stability (and control its trajectory to ground in a predictable manner), with its wing(s) and rudder. This means a very "hot" re-entry. AFAIK most re-entry vehicles "want" to re-enter as quick as possible for that reason: control and design of trajectory. But this "Starship" is so big relative to its weight that its body alone may generate enough lift force from the start, thus allowing for a slower re-entry trajectory. Like I said, this is no ordinary rocket, Everything from the manufacture method (welding outside, like water tank), through the materials and mission are different. I just stare at it in fascination. Plus it looks like a Buck Rogers Art Deco rocket, to begin with which is just unreal.

But yeah, they need to work on proper ventilation under that skirt once it's sitting on the ground. Even without a detonation event, the gasses are very toxic.

We're getting close to flying a helicopter over the Martian surface.

Here's a briefing from NASA before Sunday's flight.

Ingenuity Mars Helicopter Preflight Briefing (http://youtube.com/watch?v=9C_IyUdKKXI&feature=youtu.be#)

It's a very active period for space projects, apparently. After receiving partial support from the government (only $850 million for 2021, well below the target budget of $3.3 billion this year for a lunar program), NASA has selected SpaceX to develop the next lunar lander for the Artemis Program, no doubt in great part because of SpaceX's frugality. However, this is a more complex moon shot program than you may think. To start, the lunar lander, yesterday chosen to be SpaceX' Starship will arrive at the moon using a different platform (SpaceX Super Heavy Booster) than the one that will lift the astronauts (NASA SLS). NASA's Orion spacecraft ferried by SLS will instead take the crew to the SpaceX Starship where astronauts will board, and then use the Starship to land on the moon. And later, when an international space station known as Gateway (NASA / ESA /Jaxa) gets built in a halo orbit (read below), that will serve as a resting area and hub for flights from the Earth to the Moon and Mars... Pretty ambicious.




The moon will now be approached from a very different kind of orbit compared to the Apollo program. NASA's SLS launch system will launch the astronauts in the Orion capsule, into what is known as a "halo orbit."  So called because it's almost perpendicular to the line between the Earth and the Moon, looking like a halo above an angel's head; it's path is better described to be like western-movie cowboy's lazo, first approaching the moon, more or less on a straight line, and then taking an unlikely sharp turn to enter into a flattened loop orbit around a point in space, not a celestial body. This can happen, because the spacecraft will be navigating gravitational fields around a Lagrange point, defined as a point in space where all gravitational attraction between the Spacecraft, the Earth and the Moon (or any other three celestial bodies) basically cancels out to zero. The odd thing about these "zero gravity" Lagrangian points is that you can place objects in an unstable orbit around them, along equipotential lines. Think of the Lagrangian point as an "anti-planet" gravity wise.

Explainer: Halo Orbit
https://en.m.wikipedia.org/wiki/Halo_orbit (https://en.m.wikipedia.org/wiki/Halo_orbit)




https://www.esa.int/Enabling_Support/Operations/Angelic_halo_orbit_chosen_for_humankind_s_first_lunar_outpost (https://www.esa.int/Enabling_Support/Operations/Angelic_halo_orbit_chosen_for_humankind_s_first_lunar_outpost)

http://youtube.com/watch?v=jfCaac1ijRg&feature=youtu.be# (http://youtube.com/watch?v=jfCaac1ijRg&feature=youtu.be#)

So a Halo Orbit is basically one way to orbit a Lagrange point, instead of a celestial body. It also allows the spacecraft orbiting to be visible from Earth at all times, instead of hiding behind the moon every now and then. It's an unstable (chaotic) orbit, but stable enough with the use of thrusters to keep for a long time. The Near Rectilinear near Halo Orbit (NRHO) chosen for the Artemis Program, basically gets close enough to the moon that you can transfer into a low moon orbit and descend/ascend using less fuel that was used in the Apollo program. Similarly, getting into the NLHO from Earth also takes a lower amount of energy dissipation. The result is that you can get a lander on the moon with less fuel on board for the return trip.

Telemetry data received from Mars helicopter Ingenuity confirms that it has successfully performed its first flight.

NASA: First Flight of the Ingenuity Mars Helicopter: Live from Mission Control.
https://www.youtube.com/watch?v=p1KolyCqICI (https://www.youtube.com/watch?v=p1KolyCqICI)

Quote from: J. Wilhelm on April 19, 2021, 11:19:24 AM
Telemetry data received from Mars helicopter Ingenuity confirms that it has successfully performed its first flight.

NASA: First Flight of the Ingenuity Mars Helicopter: Live from Mission Control.
https://www.youtube.com/watch?v=p1KolyCqICI (https://www.youtube.com/watch?v=p1KolyCqICI)

First image of the shadow of Mars helicopter Ingenuity cast over the Martian surface during its flight. The on-board terrain-tracking camera captured this image.
(https://pbs.twimg.com/media/EzVWCOmVoAUpvkX?format=jpg&name=large)

Still shot from a video of Mars helicopter Ingenuity during its maiden flight. The video was captured by a camera on board rover Perseverance.
(https://pbs.twimg.com/media/EzVady9UUAY_eFU?format=jpg&name=large)

That will show those pesky Martians! We'll see how good their tripods are once we can drop pointy things down on them from our fearsome aerial forces!

Re. the SpaceX lunar lander, on a more negative note I read the 2024 dealine has been quiety dropped due to an insufficent budget. Haven't we been here before? Lots of fanfair about returning to the moon, then cost cutting, slipped dates and then the whole thing is shelved. I hope that's not the case, but I worry history is repeasting itself. Again.

Yours,
Miranda.

Quote from: Miranda.T on April 20, 2021, 07:48:11 PM

Quote from: J. Wilhelm on April 19, 2021, 11:19:24 AM
Telemetry data received from Mars helicopter Ingenuity confirms that it has successfully performed its first flight.

NASA: First Flight of the Ingenuity Mars Helicopter: Live from Mission Control.
https://www.youtube.com/watch?v=p1KolyCqICI (https://www.youtube.com/watch?v=p1KolyCqICI)

First image of the shadow of Mars helicopter Ingenuity cast over the Martian surface during its flight. The on-board terrain-tracking camera captured this image.
(https://pbs.twimg.com/media/EzVWCOmVoAUpvkX?format=jpg&name=large)

Still shot from a video of Mars helicopter Ingenuity during its maiden flight. The video was captured by a camera on board rover Perseverance.
(https://pbs.twimg.com/media/EzVady9UUAY_eFU?format=jpg&name=large)

That will show those pesky Martians! We'll see how good their tripods are once we can drop pointy things down on them from our fearsome aerial forces!

Re. the SpaceX lunar lander, on a more negative note I read the 2024 dealine has been quiety dropped due to an insufficent budget. Haven't we been here before? Lots of fanfair about returning to the moon, then cost cutting, slipped dates and then the whole thing is shelved. I hope that's not the case, but I worry history is repeasting itself. Again.

Yours,
Miranda.

I haven't heard anything from the date, other than someone from NASA cautioning SpaceX that maintaining a 2024 deadline is very "ambitious." NASA gets a budget approved every year and a certain allocation was required to maintain the bidding process and development of a lunar lander for 2021. From what I understand for this year they only got $850 million from Congress as opposed to the $3.3 billion they were requesting. In the words of many, they had no choice but to pick SpaceX, because they were the only ones willing to delay / reduce / reschedule payments for the development of the lander, because SpaceX was already developing the lander version of Starship out of pocket. Congress was expecting was to receive a proposal for a prototype contest between at least two different contractors (similar to the Lockheed Martin + Boeing YF-22 and Northrop + MC Donnell YF-23 contest back in the 90s), but NASA only selected one contractor. This was a political maneuver from NASA as this was the only way they could meet Congress's demand - the assumption being that congress was expecting otherwise to see exactly what you described, and indefinite hold on the project.

Instead NASA hung them from their own petard. There will be no delay and Artemis will go on (or they'll pretend it will), officially speaking, because SpaceX actually met all obligations. By selecting a single contractor, many of the senators from states who had strong political lobbying from local industry would have to go back to their donors and tell them that they would lose the hundreds of millions of dollars they expected from the contracts. Potentially more to the States for hosting a winning contract to build the lander. Now there might be pressure from industry in congress to increase budget for Artemis in the future fiscal years, so you can have a proper bidding contest. Congressmen would much rather see as many aerospace companies participating as possible. Sometimes in large military bids, when one contractor loses a bid they are still awarded manufacture contracts for building parts of the opponent's winning vehicle. It's all about the economic domino effect that happens when one state hosts companies with large government contracts.

Looks like SpaceX' SN 15 stuck the landing this time.

Starship | SN15 | High-Altitude Flight Test (http://youtube.com/watch?v=z9eoubnO-pE&feature=youtu.be#)

This happened on Sunday, and even though I'm not a fan of suborbital flight, it has to count as more than just a ballistic shot below the (100 km) Kármán line of the atmosphere (the ship's apogee does go over the 80km line that NASA defines as the edge of the atmosphere). Here's Sir Richard Branson behaving as badly as he can muster during the launch of VSS Unity, a Spaceship Two class suborbital space plane.


Watch Richard Branson fly to space (Virgin Galactic Unity22 supercut) (http://youtube.com/watch?v=G9MfbCjICH0&feature=youtu.be#)

Quote from: J. Wilhelm on July 12, 2021, 07:14:07 AM
This happened on Sunday, and even though I'm not a fan of suborbital flight, it has to count as more than just a ballistic shot below the (100 km) Kármán line of the atmosphere (the ship's apogee does go over the 80km line that NASA defines as the edge of the atmosphere). Here's Sir Richard Branson behaving as badly as he can muster during the launch of VSS Unity, a Spaceship Two class suborbital space plane.


Watch Richard Branson fly to space (Virgin Galactic Unity22 supercut) (http://youtube.com/watch?v=G9MfbCjICH0&feature=youtu.be#)

After the retirement of the shuttle, I though when SpaceShipOne took the X-prize nearly 20 years ago was a new dawn for space planes, but they seem to have not really progressed whilst their competitors (principally SpaceX) have overtaken them. Shame; having grown up watching Thunderbirds et.al. I still believe routine, reliable and cost-effective access to space will ultimately only be achieved via space planes.

Yours,
Miranda.

Quote from: Miranda.T on July 12, 2021, 10:23:10 PM

Quote from: J. Wilhelm on July 12, 2021, 07:14:07 AM
This happened on Sunday, and even though I'm not a fan of suborbital flight, it has to count as more than just a ballistic shot below the (100 km) Kármán line of the atmosphere (the ship's apogee does go over the 80km line that NASA defines as the edge of the atmosphere). Here's Sir Richard Branson behaving as badly as he can muster during the launch of VSS Unity, a Spaceship Two class suborbital space plane.


Watch Richard Branson fly to space (Virgin Galactic Unity22 supercut) (http://youtube.com/watch?v=G9MfbCjICH0&feature=youtu.be#)

After the retirement of the shuttle, I though when SpaceShipOne took the X-prize nearly 20 years ago was a new dawn for space planes, but they seem to have not really progressed whilst their competitors (principally SpaceX) have overtaken them. Shame; having grown up watching Thunderbirds et.al. I still believe routine, reliable and cost-effective access to space will ultimately only be achieved via space planes.

Yours,
Miranda.

The fundamental problem for me is that Sir Richard Branson's spaceplanes are only suborbital. There is no way to convert the existing vehicles into orbital vehicles because the burn duration is very short, and they're simply not designed to enter the atmosphere at well over Mach 20. But he can always redesign Spaceship One into something else and maintain the launch aircraft.

I also believe that rockets, no matter how well they can be re-used will never have the potentially short turn around time of a spaceplane that can take off horizontally from any airport in the world. That remains the Holy Grail to many people of my generation. But if you look at the public, everyone is too busy throwing mud on NASA and older modes of space transportation. The fashion today is Space X.

Part of the problem is that the public only see the Space Shuttle failures and not the gains. There's very little science education among the public nowadays, so public support is based on nationalism, politics, anything but science.

As with all of aircraft's history, development of a new power plant, such as the British RB 545, and it's derivative, the SABRE, is imperative to reach the next level of performance, namely HOTOL. I think that it can be done but it requires support from Congress and making some hard funding decisions which are not popular, and probably some redesigns of the engine configuration. I'd like to see, for example linear aerospike nozzles (for flat rectangular thrust jets), such as that used in the X-33 concept in order to relieve the fuselage's tail of any impinging thrust gases. This is a very fundamental and practical geometric design problem. I'd also like to see the return of the silica tiles and blankets, which I think solve a great deal of problems.

It's almost impossible to convince young people that the Shuttle tile system was actually very good. The practical issues of ablation and mechanical failure in the thermal protection system were partly attributable to the very large size of the shuttle. There may be other mechanical techniques out there that I'm not aware of, which could maintain the tiles in place, but designing a usable aerodynamic control surface very much depends on a skin that is resistant to heat and impervious to chemical reactions and molecular deposition.

Elon Musk is rooting for stainless steel with a special re-entry trajectory which keeps the rocket out of the atmosphere while slowing itself as much as possible (to the detriment of 3D rotational stability). I think he has not ruled out a protective skin, and quite the opposite, he needs a ceramic coating of some sort, and without more details on the re-entry parameters, I don't know how far he can push his luck. All I can think is that the rocket's body is very large, fairly light and that helps give a gigantic surface area to itself slow down at higher altitudes, plus the size helps with rotational inertia which is necessary to maintain stability while the flaps and aero-grids wait for a higher atmospheric density to function properly.

The re-entry trajectory of the X-33 was a much steeper dive, designed to employ aerodynamic forces much sooner, and you needed Inconel panels which were more or less expendable. I called them potato chips after looking at NASA's presentation in Reno, I forget exactly what year (probably 2002).

Start small, with a single passenger vehicle with drop tanks (reusable if you want to). But a vehicle that has a much faster turnaround. In that sense Branson's Spaceship One concept is better as a starting point. More like Virgin Orbital than Virgin Galactic. It could be done.

Indeed, having a skin that can survive re-entry is an even greater challenge than propulsion. What was that material that was supposedly discovered a couple of decades ago that was malleable like a metal but had the melting point of a ceramic? Was is starlight or something like that? Anyway, rather inconveniently the formula was somehow lost, so the ultimate goal here is to reproduce that formula (if it ever existed in the first place...)

Yours,
Miranda.

Quote from: Miranda.T on July 15, 2021, 08:24:01 PM
Indeed, having a skin that can survive re-entry is an even greater challenge than propulsion. What was that material that was supposedly discovered a couple of decades ago that was malleable like a metal but had the melting point of a ceramic? Was is starlight or something like that? Anyway, rather inconveniently the formula was somehow lost, so the ultimate goal here is to reproduce that formula (if it ever existed in the first place...)

Yours,
Miranda.

I don't have a clue, never heard of it. Inconel was the material used for the X-33, it's melting point is between 2,350°F and 2,460°F (1,290°C and 1,350°C). Beyond that Titanium has a melting point of 1668 °C (3034 °F). The chemical reactivity of the material may be as important as the melting point, because oxidation and chemical deposition of radicals creates heat concentrated on the surface of the metal.

Happy Cosmonautics Day!

(https://cs12.pikabu.ru/post_img/2022/04/12/11/1649788520118621535.jpg)

My apologies, ladies and gentlemen, I haven't had much time to write anything on the Artemis-1 mission. However, about an hour ago,live coverage of the launch started at NASA TV.  This is the website,

https://www.nasa.gov/content/live-coverage-of-nasas-artemis-i-mission-to-the-moon

This is the schedule for the live coverage this morning:


But the stream actually is live on YouTube, so I can embed it below for all of you to see.

https://www.youtube.com/watch?v=21X5lGlDOfg

-Update: unfortunately the launch has been scrubbed today, as the engineers detected a leak in one of the engines.  The launch will happen some other day, but hopefully very soon this week, while the rocket is fueled up.

This is an old-school type launch, completely with holds and scrubs. The space shuttle missions would suffer similar hiccups.

-Update Monday 1:42 pm.  There's a slim chance that the launch will happen on Friday.  During fueling engineers noted that one of the engines wasn't cooling properly, when you run fuel through the outside of the nozzles (the "bells") and the rest of the engine. The purpose of pre cooling is to prevent a thermal shock in the engine systems when a rush of fuel goes through it. The suspected cause of the higher temperature on Engine 3 is a hydrogen leak not inside Engine 3, but in the systems that feed it. 

There were other expected issues with bleeds from the fuel loading systems, but those were expected and dealt with properly. Hydrogen is a very small molecule and it's way too easy to get a leak even with a microscopic gap in between gaskets. The procedure is to stop and slow the fueling until the gaskets cool down and that'll generally allow them to seat properly.

Unfortunately having to deal with an intentionally slowed fuel pumping meant they couldn't firmly observe the leak on Engine 3. The engineers didn't feel they had enough time to fix that issue within the launch window.  They're still going to try to launch on Friday, but given the seriousness of the leak (hydrogen), they're just saying there's a "non zero" chance of fixing it and launching by Friday.

-Update Monday 5:22 pm. After meeting around 3 pm on Tuesday mission management will brief the public on the situation. The next launch window is Friday from 12:33 pm to 2:33 pm EDT (UTC-4)

-Update Tuesday August 30: Launch has been moved to Saturday, Sept. 3. The two-hour launch window opens at 2:17 p.m. ET (18:17 UTC).  Looks like the engineers continued working through midnight Monday evening and found where the leak happened, and later they drained the vehicle to get access to the affected parts. After a meeting today they choose to move the launch to Saturday.

-Update Saturday 3 August: We're about 3 hours away from launch. I heard it on the grapevine that subsequent analysis revealed that a faulty temperature gauge led the engineers to assume there was a leak in the supply of Engine 3. It's now assumed that Engine 3 was being cooled properly all along. I haven't had the time to confirm that, but launch is now proceeding normally.

-Update Saturday 3, 10:47  am. For the last ½ hour, engineers spotted and have tried to fix a *real* leak from an 8 inch quick disconnect hydrogen supply line.

-Update Saturday 11:17 am The launch of Artemis I has been scrubbed for the second time.  Awaiting a briefing from NASA.

-Update Saturday 5:45 pm EDT. Engineers are giving up on launching within this window of opportunity which ends on Tuesday.  According to NASA Administrator Bill Nelson, the next window for launch will not happen until early October. The next launch will be attempted closer to mid October, however, to allow Space X to launch crew to the International Space Station.

Engineers will have no option but to roll back Artemis back into the Vehicle assembly building, regardless of the nature of the leak. They will establish access to the affected area and determine whether they can fix the problem inside or outside the Vehicle Assembly Building, but either way, Artemis will have go back to the building. The reason is that certain procedural requirements must be followed to certify the termination of the launch attempt, like resetting the systems' batteries for public safety purposes.

Given the probable time frame for the next launch attempt, it'll be best to follow the NASA Artemis Blog:

https://blogs.nasa.gov/artemis/

 :'(

Quote from: von Corax on September 03, 2022, 11:35:28 PM
:'(

Yah, I know. And don't even think about looking at Twitter right now, because all the SpaceX/Elon Groupies™ are having a field day monday-quarterbacking with their advanced degrees from the Twitter Graduate School of Engineering™

Artemis will get off the ground eventually - I'm happy to wait as long as necessary because I want it to work! First the moon, then Mars. I'd like to go to Mars!! ;D

I'm sure there are a lot of people who want me to go to mars too...  ;D

Update Tuesday 6 September: The engineers have decided to fix the quick disconnect port right on site on Pad 39A. I don't know what that means for resetting the batteries and flight termination certification, though.

Quote from: Banfili on September 05, 2022, 12:49:36 PM
Artemis will get off the ground eventually - I'm happy to wait as long as necessary because I want it to work! First the moon, then Mars. I'd like to go to Mars!! ;D

Oh there's a lot of geology to look at on Mars.

Quote from: Synistor 303 on September 06, 2022, 12:28:40 AM
I'm sure there are a lot of people who want me to go to mars too...  ;D

I don't have anyone i would like to send to Mars, but I know plenty of people who look like they're from Mars.
;D

(https://imgs.xkcd.com/comics/artemis_quote.png) (https://xkcd.com/2668)

[gossip]

This is not on the NASA Blog, but there's rumours on the grapevine. According to some reporters of space industry, NASA is trying to preserve a September launch, instead of October.

There are several things happening here. One is the requirements to satisfy the Eastern Range authorities that regulate civilian and military space activities in the US. Namely,the batteries need to be reset, since they've been draining power for a very long time, since Artemis was assembled. That reset traditionally happens at the vehicle assembly building (VAB). But the source of liquid hydrogen (LH2) is at the launching pad. Any wet dress rehearsal or tests involving fuel must happen on the pad.

So engineers are now requesting permission to launch earlier and extend the accepted "lifespan" of the batteries per regulations.  There's also regulations on the shelf life of the assembled solid rocket boosters which set a limit, and which I understand is already two months overtime already, since the rocket was certified to fly within a one year of being assembled.

The engineers feel the solid rocket boosters' actual lifespan is no trouble, but I haven't heard on a risk assessment for battery depletion. Perhaps that is the reason for the sudden rush. I'm assuming the engineers feel it's acceptable

The unofficial tentative date for launch would be either September 23 or September 27.

[gossip]

Update Wednesday September 21, 1:20 pm EDT: Today cryogenic fill tests on the SLS are bring performed as I write this post. The engineers encountered the same leak on the quick disconnect again, at the same time point when they encountered the leak during the previous launch attempt.  The engineers seem to have successfully re-set the leaky connection by applying a thermal cycle, using a fast / slow fill procedure, reducing the leak rate to 3% which is considered acceptable. The filling of the lower stage tanks is nearing completion. Filling of the upper stage follows

Welp. That's it for the September launch date. Hurricane Ian is approaching the eastern coast of Florida, and NASA has decided to roll the rocket back into the Vehicle Assembly Building. Probably November will be a target month for the next launch, but given that the permission for the life extension for the batteries is expiring, this means the rocket will probably have to be partially disassembled to allow access to the batteries which need to be reset. The Solid Rocket Boosters' approved lifespan is also expired. I'm not sure what this means at the moment for a new launch date.

The day was punctuated by a successful impact of an international probe called DART on a binary asteroid system, Dydimos - Dimorphos, to see if changing the trajectory of the system was possible by way of ballistic impact. The test was successful.

https://youtu.be/Xg5iSHAsQ_A

It's taking almost as long to launch as it does to get anywhere on the M25 ......

Quote from: Cora Courcelle on September 27, 2022, 04:12:45 PM
It's taking almost as long to launch as it does to get anywhere on the M25 ......

In fact, the NASA Crawler Transporter probably moves at about the same speed... 10 hours to get the SLS back to the Vehicle Assembly Building.

*In Old man's voice*
"Eh, those youngster whipper snappers at Cape Canaveral. They probably want to break the sound barrier or somethin' "

My contribution to the discussion on ærodynamics:

Quote from: von Corax on September 29, 2022, 02:10:06 PM
My contribution to the discussion on ærodynamics:

(https://imgs.xkcd.com/comics/wing_lift.png)
XKCD #2678 (https://xkcd.com/2678)

Ha ha ha!  I've heard of riblets ("shark skin") to reduce turbulence, but it never occurred to me to use fear to increase the lift to drag ratio

I imagine that by now, the launch of Artemis I has been forgotten. Well, to recap on the recent news, Artemis I last week on Thursday survived Hurricane Elaine, and since the engineers did not have the time to send it back to the assembly building, they decided the risks of translation might be worse than the damage caused by the hurricane on the rocket, based on expected wind speeds.

In spite of winds that slightly exceeded the maximum lateral wind rating of Artemis I, the rocket has been deemed flight worthy and will have it's first launch opportunity in the first 1 or two wee hours of the morning, local time, this Wednesday. You can look at the links above to follow up on the progress, although NASA has been more tight lipped about this launch than they were the last time. They only had one statement on their decision to keep the rocket on the launch pad, and a press briefing tonight on their decision to press forward...

I'll return with more details as soon as I can.

Artemis I was given the "go" to launch this morning at 1:04 am EST, 6:04 UTC/GMT when a two hour launch window will open. That's tonight for us in the US and today this morning for you on the other side of the pond!

The first stage of the rocket was filled and topped off with oxygen without issues. Liquid hydrogen for the first stage continues at high speed. The upper stage is 18% full with hydrogen, and 44% full with oxygen. No issues reported.

Weather is 90% favourable for launch.

The video feed on NASA.gov is live now:

http://youtube.com/watch?v=21X5lGlDOfg

The launch was, by all accounts, a roaring success.

https://www.cbc.ca/news/science/artemis-1-third-attempt-1.6651139 (https://www.cbc.ca/news/science/artemis-1-third-attempt-1.6651139)

Quote from: von Corax on November 16, 2022, 02:44:54 PM
The launch was, by all accounts, a roaring success.

https://www.cbc.ca/news/science/artemis-1-third-attempt-1.6651139 (https://www.cbc.ca/news/science/artemis-1-third-attempt-1.6651139)

More than that, it was vindication for NASA employees who have endured accusations of political bias and not being qualified to develop, engineer and conduct the Artemis space program.

The Artemis I mission is proceeding nominally. No problems have been reported so far. At least the SLS launch vehicle operated flawlessly, cementing it's position as the only viable interplanetary launch system at the moment.

Some more photos

NAS Artemis-1 mission has come to and end. The Orion spacecraft has reentered the atmosphere and splashed down off the coast of California after swinging around Australia in a northbound path.


The return mission involved skipping over the atmosphere twice, to slow down from a 24600 mph/ 39600 km/h reentry speed. 

There's a lot of info regarding the orbital Artemis I used to get to and back from the moon.


Also, I've tweeted/tooted (I'm on Mastodon as well) on details on Orion's reentry thermal protection system and a whole bunch of cool photos. Also, I should note that the ESA was heavily involved with the Service Module, so there's more info on that. I'm not sure if you guys want to read about it. So, I'll stand by to see if I get opinions on this thread!

The forum is kind of quiet at the moment. I'll be posting more progress and projects soon, but I thought this quiet period would be a good time to drop this video I found online.

It's the IMAX documentary film "The Dream is Alive" about the Space Shuttle system. This is a presentation by the Smithsonian Institution's National Air & Space Museum & Lockheed Corporation In Association with NASA. The original film was narrated by Walter Cronkite. It's got good sound but it's a bit low, so raise the volume and play in stereo.


https://vimeo.com/541887307

I have been thinking (not very hard) and wondering, if a base was set up on the Moon or Mars, with low gravity and not a dense atmosphere, could airships be a cost effective way to get around (rather than landcraft)? Could you use something other than hydrogen or helium or would the problem not be with the gravity and more with the lack of atmosphere, so there is nothing to be lighter than?

Sorry if this has already been discussed.

Sorontar

Quote from: Sorontar on March 05, 2023, 12:37:11 AM
I have been thinking (not very hard) and wondering, if a base was set up on the Moon or Mars, with low gravity and not a dense atmosphere, could airships be a cost effective way to get around (rather than landcraft)? Could you use something other than hydrogen or helium or would the problem not be with the gravity and more with the lack of atmosphere, so there is nothing to be lighter than?

Sorry if this has already been discussed.

Sorontar

Ahh, yes! Da Vinci on Mars! No, I don't think it's been discussed this way before, actually.

In theory, a rigid balloon made from unobtainium containing a perfect vacuum would yield the theoretical maximum buoyancy you could ever get out of any medium (surrounding) of a given non zero density. I think Leonardo Da Vinci posed this very problem.


You get where I'm going. There's a final limit. The problem with buoyancy is that you depend on the ratio of mass density of surround medium or an atmosphere to the mass density inside the envelope to generate lift. In a free body diagram of the floating vessel, the weight of the surrounding medium you're displacing must be equal to the weight of the vessel and envelope for equilibrium, or alternatively the weight of the medium displaced must be greater than the weight of the vessel and the gas contained therein for a positive climb rate (acceleration).

That's what makes wooden and even metal hulled ships so practical in the ocean on Earth, with relatively little volume needed inside the vessel: water is very dense. The space inside a wooden ship approaches the density of air, 1000 times less than the density of water.

Airships on the other hand need to displace far more volume because the ratio of density of water to air (the medium) is 1000, so to lift the same hull weight, the airship's envelope needs to be much bigger than a wooden ship at the density of air. Needs 1000 times more volume than a water craft.

The concept is not new for the topic of exploration on other planets. But material constraints (strength of fabric and weight of fabric) come into the picture (not mentioning exposure to radiation, harsh conditions, etc).

On Mars it's definitely a more difficult task than on Earth. On Mars, you only have 1/3 the gravity, so that helps you, but the atmosphere density is much lower than on Earth, less than 1%. Not as bad as the ratio between water and Terran air, but still a problem. The volume required to lift the same ship on Mars is ~100/3 or say 33 times larger than the equivalent airship volume on Earth.

So it's doable but challenging relative to Terran airship design due to the size of the envelope. There's a silver lining, though: because the average molecular weight of Martian air is higher (carbon dioxide) relative to Mars' low atmospheric pressure (when compared to Earth), the pressure differential between the inside and the outside of any *rigid* envelope is lower on Mars. If this was a nitrogen oxygen atmosphere the pressure differential would be higher. You can take advantage of that low pressure differential if you're willing to entertain a rigid envelope.

You see, to keep the envelope realistically small, some of the methods proposed and studied seriously include a variation of the method proposed by Leonardo Da Vinci: a rigid envelope with a partial vacuum (Yes I know!). No lifting gas involved, regardless of ballast method.

https://www.spaceanswers.com/futuretech/future-tech-martian-airships/


https://www.nasa.gov/directorates/spacetech/niac/2017_Phase_I_Phase_II/Evacuated_Airship_for_Mars_Missions/

Also, there are many scholarly papers on Martian exploration by way of lighter than Martian air craft - I haven't read this one, it's just an example of where to look. Honestly, I haven't even thought about the problem, but it's a very interesting topic.

https://arc.aiaa.org/doi/abs/10.2514/6.1999-896

Alas, the case for a Moon airship is non existent I'm afraid; the medium density is zero, and therefore a sphere made from unobtainium with a perfect vacuum within, would give you zero buoyancy, and the only force acting on the airship is its own weight including the envelope's weight.

Da Vinci will go to Mars, but not the Moon.

Quote from: Sorontar on January 24, 2021, 09:06:23 AM
I remember when Australia II had its legendary winged keel and that was regarded as a such a novel concept. Certainly, the power of the wind can really move you, whatever your craft

Class 5 Land yachts racing and fails on 90 Mile Beach (http://www.youtube.com/watch?v=LRTahy3OiuU#)

Everyone wanted a winged keel after that. I recall  the big kerfuffle over the voluminous "skirts " put around the bottom of competing boats , to protect them from the prying eyes of rival teams.

I'm not one for such things usually , those land yachts look tempting though. They could take off  as a recreational adventure sport , now that tourist travel has opened up again

Quote from: J. Wilhelm on January 23, 2021, 06:10:31 AM
I don't post here very often, and much less on the subjecty of sailing. But the last time I kept with sailing technology it was the late 1980s and I was a young lad starting college in San Diego, which is what introduced me to the America's Cup and that disastrous international scandal between New Zealand and the United States. The issue being lawsuits back and forth over what kind of technology could be used to meet the race requirements, and after a bitter complaint from the USA over certain technology used by New Zealand, the Americans decided to retaliate by bringing a rigid-sail catamaran as allowed by the loopholes in the vaguely defined rules of the race...

https://en.wikipedia.org/wiki/1988_America%27s_Cup (https://en.wikipedia.org/wiki/1988_America%27s_Cup)

(https://upload.wikimedia.org/wikipedia/commons/f/fe/Americas_Cup_1988_By_Phil_Konstantin.jpg)

But after not paying attention to the sailing technology over the last 3 decades, I saw today on NBC Sports Network the latest race beween the UK and Italy in the 2021 Prada Cup which is taking place between January and February of this year (currently ongoing).

https://www.skysports.com/more-sports/sailing/news/30786/12185095/36th-americas-cup-stevie-morrison-talks-development-favourites-and-the-prada-cup (https://www.skysports.com/more-sports/sailing/news/30786/12185095/36th-americas-cup-stevie-morrison-talks-development-favourites-and-the-prada-cup)

(https://pbs.twimg.com/media/EsZVk0cXAAAYUVt?format=jpg&name=large)

What I saw gobsmacked me. The easiest description of the craft is a racing craft with dual articulated hydrofoils, each *with functional ailerons*, on a hull that acts as a lifting body (airfoil cross-section), naturally a wing plus a sail, and oh yes, the thing can cruise up to 45 knots and turn "on a dime" to tack using said ailerons and rudder. No engine of any kind, just the wind, and the hull barely gets to touch the water.  So there's so much going on that I'm going to post one of the races, and let you marvel at these craft.

Full Race Replay | Day 1 | PRADA America's Cup World Series Auckland, NZ (http://www.youtube.com/watch?v=ne-covgb3ao#)

From a non engineering or nautical design perspective -
I've never been much taken with watching sail boat competitions. They were a bit boring. I avoided them. Until a friend mentioned some international yacht race in the South Island that was being televised. [She is more interested in rich boaties, than actual boats]. She mentioned the scenery , so I switched on .

I was completely taken aback by the modern racing yacht designs. They were perching on the water ready to strike, with giant metal insect legs straight out of a scifi movie. It got me watching

Quote from: Hurricane Annie on April 23, 2023, 09:51:48 AM

SNIP

From a non engineering or nautical design perspective -
I've never been much taken with watching sail boat competitions. They were a bit boring. I avoided them. Until a friend mentioned some international yacht race in the South Island that was being televised. [She is more interested in rich boaties, than actual boats]. She mentioned the scenery , so I switched on .

I was completely taken aback by the modern racing yacht designs. They were perching on the water ready to strike, with giant metal insect legs straight out of a scifi movie. It got me watching

Indeed, sailboat racing was never something I knew much about or watched. The only reason I knew something about it, is because when I moved from Mexico to the US, I settled in San Diego, right when the controversial America's Cup was taken back by Dennis Conner with the 12 ft long rigid sail (wing) catamaran "Stars and Stripes 87.". The ship was docked right next to a park and shopping center I frequented, so I got to see the ship in person

In other news, I very seldom post anything by SpaceX, but a couple of days ago the complete Starship two stage rocket was launched for the first time.  While SpaceX and Elon Musk enjoy near cult (or full cult) status online, it's during this launch that you see the real limitations of the so called "iterative design," where systems are designed partially, tested to failure, then redesigned and flown again, over and over, until you have a viable system.

In the past, this design approach applied to Falcon 9 and Heavy Falcon vehicles has forever changed the field of rocket, forever changing the expectation of a rocket as a disposable vehicle.

Unfortunately, while the approach was very successful on the development of rocket stages, the philosophy has come back to haunt SpaceX, because when you design a rocket you have to design "Stage Zero" otherwise known as the launch pad.  It looks like the initial shock from engine start and acoustics generated by the enormous thrust of Starship cracked and literally pulverized a "bench" styled launch platform known as the "launch ring." The launch ring was only standing on top of a concrete platform.


Aerospace engineers who work at NASA developing launch platforms, explain that gas pressure is enough to crack concrete and inject high pressure gases into the soil, with enough power to lift large pieces and repeat the injection process, eventually creating a vertical jet of burning gases and debris flying upwards at high angles. For that purpose, "thrust diverters", basically a system of channels, tunnels and ramps are built upon a massive platform to divert the flow sideways in a safe manner.  In spite of SpaceX' collective human expertise, they chose to not built a diverter for what is basically the biggest, most powerful rocket ever assembled. Speculate at will why they chose not to do build a diverter (Baffled, we're debating that decision among the engineering community right now).

The end result was a giant crater in the ground with debris including very large chunks of concrete flying very far away from the launch pad, impacting launch facilities and much further than that, covering the township of Boca Chica in "sand" made from pulverized concrete and regolith soil in the area. There were some interesting souvenirs found by locals and tourists to be found all around.


It's quite probable that some of that blown debris flew upward and impacted several engines and one hydraulic system. It's also unlikely that the FAA will grant SpaceX permission to launch again anytime soon without a complete redesign of the launch pad. So it's all speculation right now, but I wager this is going to set the Starship program many months if not years back. Bad news for NASA too, since the Starship 2nd stage was selected as the Lunar Lander for the Artemis Moon program. It may be time to restart the bidding process and select a fallback landing vehicle from the other two industry conglomerates who submitted their bids to NASA, which will probably sound like music to various State Senators in Congress, not to mention aerospace companies.

I'll let rocket aficionado Scott Manley tell the rest of the story as it happened a couple of days ago.

http://youtube.com/watch?v=w8q24QLXixo

Interesting, Honestly spaceX does not interest me as much as the vintage technology, but i was a bit suppried when i red Your post here since this is basic knowledge that has been known for decades (at least since the 1940s), even smaller rocket engines, like the Russian RD-253 will do this on a platform constructed this way. However i think the Russian base are made with a tunnel system made of a special concrete mixture, i am not sure what it is, but it seem to be many times stronger than regular concrete, the modern mixtures used in the Swedish nuclear powerplant walls are even stronger and i seen videos where they crashed a decommissioned fighterplane into a test piece and the plane was literary pulverized, but the concrete wall barley had a dent, regular construction concrete had been pulverized with a fraction of that force.

The latest from today's Hackaday: Sharkskin Coating Reduces Airliner Fuel Use, Emissions (https://hackaday.com/2023/08/23/sharkskin-coating-reduces-airliner-fuel-use-emissions/).

Comrades! Happy Cosmonautics Day!

(https://ic.pics.livejournal.com/andrei_bt/18425682/3076096/3076096_original.jpg)