No Future Space Flight?

[WillC.]

My name is Will and i reciently found this site, its an awesome site and has answered a lot of my questions so far but i havent found anything about this yet......

As exciting as all the new technological advances and amazing discoveries are...isn't the future of all space exploration threatened by the debris left behind by the thousands of space craft we've launched? A golf ball sized piece of debris could potentially take down the entire space station! And theres a lot of that junk up there. Am i way off here or what?

[Ronald Brak]

Hi, nice to meet you. Very soon someone will come along and list a whole heap of threads on this topic. But before that happens I'll tell you that space junk is a problem, but not an insumountable one. Big pieces can be tracked and hulls can be made strong enough to survive impacts with little pieces and fingers can be crossed to avoid what's in between.

[WillC.]

are there any plans to remove or destroy somehow? because eventually wont there will be too much junk to get off our planet?

[eburacum45]

There is a concept out there for catching small particles of debris, consisting of a tube filled with some soft material, such as an aerogel. The junk is caught in the tube and decelerated by the soft material, and the wall of the tube prevents the soft material from splashing and becoming more spacejunk.

However I can't find any references to this concept at the moment.

[David Mc]

I think it would be a great to have a satellite who's purpose is to clean up.
The demand on that machine couldn't help but improve the technology.
Especially if it's an autonomous unit.

Not an answer, but the thought excited me :)

[formulaterp]

are there any plans to remove or destroy somehow? because eventually wont there will be too much junk to get off our planet?

Orbital debris will eventually clear itself, so there is no pressing need to perform a cleanup operation right now. Rather the focus has been to design spacecraft/rockets/satellites in ways which minimize the creation of new debris sources. The recent test of a Chinese ASAT system was not a step in the right direction.

http://www.orbitaldebris.jsc.nasa.gov/mitigate/mitigation.html

[Peter Wilson]

...isn't the future of all space exploration threatened by the debris left behind by the thousands of space craft we've launched? Space is a dangerous place :think:

I'm thinking budget cuts are a more immediate threat than debris, however.

[Larry Jacks]

I know of 4 breakups this year (one of them was the Chinese ASAT test) that resulted in over 2000 cataloged pieces of debris. This is a serious issue but not one easily resolved. Preventing large scale breakups like the one that happened when a Russian upper stage exploded is a big step forward, as would be eliminating ASAT tests. The upper stage failure is particularly challenging because it's in a highly eliptical orbit with the perigee in the southern hemisphere, making it difficult to track with existing space surveillance radars.

As to removing the debris that's already up there, that's a difficult issue. Trying to develop a spacecraft to collect the debris is a huge challenge because the debris exists in many different orbital planes and at different altitudes. It would take a lot of energy (propellant) to rendezvous with one piece, capture it, maneuver, and rendezvous with another piece.

I've read of a proposal to use a high powered ground-based laser to take out debris. Apparently, the goal is to cause the debris piece to deorbit or vaporize. I don't know if anything ever came of the proposal or if anyone ever tried it.

[WillC.]

were any of those breakups due to space junk or other reasons? and over time wont those 2000 pieces of matter breakdown to hundreds of thousands of smaller pieces making it even more difficult? i like the aerojel idea and the laser idea and i think we should seriously consider them..because i know if i was an astronaut space junk would be on my top 5 lists of worries

[Larry Jacks]

None of the breakups were due to debris according to my sources. One was the Chinese ASAT test in January. It produced over 1000 cataloged pieces*. The Russian upper stage explosion was due to a lot of propellant being left onboard due to a premature engine shutdown. The best practice is to vent residual propellants from an upper stage to prevent an explosion but sometimes it isn't possible. It produced hundreds of pieces, too. The other two breakups "only" produced from 10-50 cataloged pieces each. Analysis shows they were unrelated to space debris.

*By cataloged pieces, I mean pieces that can be repeatedly tracked so that good element sets can be generated. Every space surveillance sensor has a size limit on how small of an object (Radar Cross Section or RCS for radars, illuminosity for optical sensors) it can track. Objects smaller than that certainly exist but can't be tracked. In addition, if only one or two sensors can track an object, it's harder to generate a high quality element set, making it hard to repeatedly track the object. Also, small objects with low mass are relatively easy to have their orbits perturbed. Those in low orbits will typically decay quickly, especially when solar activity causes the atmosphere to expand. Those in higher orbits might get perturbed enough to make it hard to consistently track.