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Crowded skies?

PostPosted: Tue Aug 24, 2010 8:34 am
by Intranaut
Recently I attended the Australian Youth Aerospace Forum and we attended a few lectures on various areas of the aerospace industry. Two of which seemed to conflict with each other a bit, and not in the way science and engineering love to have a go at each other.
One lecture from an Australian fellow working with NASA was about the issue space debris. It was his job examine the shuttles on their return for any evidence of micro trash collisions and as I understand it, his work was also in the field of calculating when best to send up missions in relation to how much junk was flying over head, giving missions the go if there was 98% chance of the ship not blowing up or killing a crew member. When asked whether there were any plans to decrease the level of space debris he said that at present, there was not. Apparently the Chinese had tried to get rid of an old communications satellite and in doing so, exasperated the problem by creating a great number of smaller pieces of debris that now needed to be tracked for safety reasons.
So without any way to get rid of space junk, I don't see the situation getting better any time soon.
But the plot thickens!
We later spoke to a number of people involved in scramjet research. It was their prediction that if they succeed in developing working scramjets, it could be viable to launch mini-satellites at a university level cost with a small rocket to get the engine to hypersonic velocities before switching to scramjet until the air becomes too thin and reverting to rockets again. In this way you use a lot less fuel. More efficiency. Cheaper. It sounds fantastic, and in a lot of ways it is, I mean, I could potentially launch a device into orbit for post-grad research. But my concern is that if everyone is sending up satellites into already crowded skies, eventually it may well become impossible to launch anything within a reasonable margin of success.
So, solutions anyone?

Re: Crowded skies?

PostPosted: Thu Aug 26, 2010 11:23 pm
by RickLewis
Here's one solution that I saw on the BBC website recently. Basically you attach a small sail to pieces of space junk and it makes them de-orbit faster:

http://news.bbc.co.uk/1/hi/sci/tech/8590103.stm

Not sure HOW you attach such sails to every bit of junk, though! Sound to me like what we need is a vast orbiting vacuum cleaner (to clean the vacuum har har!)

Re: Crowded skies?

PostPosted: Fri Aug 27, 2010 4:53 am
by Intranaut
Oh har har :P

Perhaps it would be more viable if you could send a out a small army of either automatic or ground controlled ones. I imagine that there might be a few people willing to remote control a machine that destroys stuff in space?
So say if you've got like a depot where these machines could return to get a new set of sails to attach to something and themselves charged up?


But my original idea was more like your vacuuming the vacuum! Bad as it is. I was wondering if you (or anyone) know(s) what the magnetic properties are of some of the materials we use in satellites and whatever makes up all that space junk?

Re: Crowded skies?

PostPosted: Thu Sep 02, 2010 5:07 pm
by JamesG
The problem is the differential velocities. You have to match orbits precisely otherwise you will have either a high energy collision or your "near miss" with a magnetic grapple will simply fling both the target and the recovery vehicle off in new unpredictable orbits.

NASA is working on a "garbage collection" scheme. LEO salvage is a possible viable business model someday.

Re: Crowded skies?

PostPosted: Thu Sep 02, 2010 10:13 pm
by Intranaut
Ahh see that's what I was hoping somebody knew about. Could you link me?

Re: Crowded skies?

PostPosted: Mon Sep 06, 2010 3:27 am
by JamesG
It was during an AIAA conf. Just Google: "NASA space debris plan" or the like, and you'll get a bunch of links.

Re: Crowded skies?

PostPosted: Mon Sep 06, 2010 6:32 am
by Intranaut
Thanks James! I was just reading up on the idea of the electrodynamic tether. Very interesting.

Re: Crowded skies?

PostPosted: Wed Mar 13, 2013 1:31 am
by microlaunchers
Perhaps the answer to the crowded LEO problem is to abandon LEO and go for the inner Solar System where there is literally a trillion times the room. See http://microlaunchers.com/ for the idea.

Technology, components available now allow this. To get out of the rut we're in some new breakaway strategy is needed.

Remember Heinlein's "get to low Earth orbit and you're half way to anywhere" how about "get to low Earth orbit and you're ONLY half way to anywhere"

The solution to a problem can be to just leave it.

Having renewed involvement here, will be posting in various places...

Re: Crowded skies?

PostPosted: Sun Nov 10, 2013 12:21 pm
by Spaced
When you say go for the inner Solar System, what do you mean? Obviously most satellites need to be in Earth orbit to do their jobs. Are you talking about space stations? Are you suggesting that rather than having them in Earth orbit they should be in independent orbits around the Sun for safety reasons? Or am I misunderstanding you? :?:

Re: Crowded skies?

PostPosted: Mon Jun 23, 2014 11:18 pm
by RickLewis
Apparently the ISS uses something called Whipple shielding to protect itself from impacts by small pieces of debris. It is some kind of multi-layer shield fixed to the outer surface of the station.