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Speeding Object Makes Small Hole In the ISS Solar Array
New submitter cute_orc writes "The International Space Station has been hit by a small object. Chris Hadfield, an astronaut currently on the ISS, described it in his Twitter feed as 'a small stone from the universe.' He also said he was glad it didn't hit the hull. Jim Scotti, a planetary scientist from the University of Arizona, thinks the object may have had a different origin: 'It's unlikely this was caused by a meteor; more likely a piece of man-made space debris in low Earth orbit.'"
Sort of?
We have a project to identify and track all the space-junk we can, but the library is far from complete. Once we know where one is and how fast it's going, it doesn't deviate much from that.
We make a practice of avoid the junk we know about. Intercepting it, on the other hand, is a fools errand. You're talking about shooting a bullet down with a gun. Hypothetically: sure, but in reality, it's not gonna happen.
Vaporizing them isn't going to help much and it takes too much energy. It also has the risk of generating *more* space junk, just smaller. However, there is a proposal to use lasers against the growing cloud of space junk in orbit. This plan, however, isn't to vaporize them. The plan is to use the small momentum generated by photons to cause the junk to deorbit. http://www.wired.co.uk/news/archive/2013-04/29/laser-space-junk
A laser isn't as unfeasible as you might think. All it has to do is ablate a tiny bit of material from the target, enough to raise it's apogee a bit which then pushes the perigee deeper into the atmosphere causing it to fall out of orbit relatively quickly (a handful of orbits later). The idea isn't to spot an incoming rock and zap it away, it's to keep the general orbit clear of debris. And the best part is, using adaptive optics, it's possible to base such a system on the ground.
Only above a certain size (1cm or so?), and yes, they do deviate because they hit things while they orbit.
Even worse is that, you cannot intercept them because you risk making the problem worse - one large piece of debris is easier to deal with than many smaller pieces, and the smaller pieces often form clouds of debris which can cover a larger area, which create more debris as they hit more stuff.
There is a critical point where we would effectively be trapped because the space debris would cause chain reactions which spray off more debris, which hit off more stuff and make more debris, etc. Like an uncontrolled nuclear reaction.
The only way to clean it up is to deorbit it, and orbital mechanics say to do that, you can only decelerate it (your orbit altitude is determined by your speed - go faster, you go higher. Go slower, you go lower)