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The Guild of Icarus: Aerospace Engineering and Aeronautical Club

Started by J. Wilhelm, October 05, 2015, 09:24:15 AM

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J. Wilhelm

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

Miranda.T

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

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.

Peter Brassbeard

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

morozow

Sorry for the errors, rudeness and stupidity. It's not me, this online translator. Really convenient?

Miranda.T

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.

Yours,
Miranda.

J. Wilhelm

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.

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)

Miranda.T

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.

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.

J. Wilhelm

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...

J. Wilhelm

#108
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

Peter Brassbeard

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

Miranda.T

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, 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.

J. Wilhelm

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, 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

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.

J. Wilhelm

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

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.

Prof Marvel

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.
MIGRATION to Spare Goggles under way

J. Wilhelm

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).

J. Wilhelm

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

This video also caught my eye :

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.

J. Wilhelm

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

Miranda.T

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.

J. Wilhelm

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).

Miranda.T

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.

J. Wilhelm

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

Miranda.T

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.

J. Wilhelm

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

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

I wonder if they'll have a watching party.

J. Wilhelm

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://www.fireflyspace.com/

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.

Firefly Alpha Launch Vehicle



Firefly's Aerospike Engine


morozow

Sorry for the errors, rudeness and stupidity. It's not me, this online translator. Really convenient?