It seems that it is not only the Earth that has been partly filled with junk and trash. Space has gotten its part too. There is so much debris going around in the orbit, that it is posing a real threat not only to another satellites but also to space shuttles and spacecraft, for example to the International Space Station (ISS). Therefore, Pentagon has requested ideas on any possible solutions how to clean the mess.

According to DARPA’s description, “Since the advent of the space-age over five decades ago, more than thirty-five thousand man-made objects have been cataloged by the U.S. Space Surveillance Network. Nearly twenty-thousand of those objects remain in orbit today [...]“. On top of that, “These figures do not include the hundreds-of-thousands of objects too small to be cataloged, but still large enough to pose a threat to approximately nine-hundred operational satellites in orbit around the Earth.”

The debris consists of a bit of everything, varying in size, form and material. It is an interesting mix of, among others, spent rocket stages and defunct satellites, explosion fragments, paint flakes, slag from solid rocket motors, coolant released by nuclear powered satellites and small needles. Apparently even the very small parts like paint flakes can be potentially harmful, as they can cause erosive damage (sandblasting-like) when in contact. Therefore, Pentagon is not only interested in cleaning the big parts, “The debris population of interest includes small (1-10mm) [and] medium (1-10 cm)” sized pieces as well.

Any collision or destructive measure will increase the amount of debris enormously, and for example in 2007 an anti-satellite missile test made by China created in addition to national pride a debris field of some 40,000 pieces. The USA could not wait try its own the next year (animation of how it all happened here). There was also a more natural collision earlier this year between an Iridium satellite and a retired Russian satellite. What ever the solution for the problem, destruction seems to be not one of them.

It is good that Pentagon has rolled up its sleeves in order to do something for the problem, even though it might have been a good idea to think twice before destroying satellites with missiles (then again, have not heard any possible interest to the issue on the part of China). I suppose one solution to the problem lies in the heart that we have not taken our space junk far enough. The problem is not that it is there, the problem is that it is too close.

Next time, when a satellite has done its job it should be directed towards outer space. Once you cannot see it the problem ceases to exist. For the stuff that is already there, well, I recommend small steps. From now on when the people at the ISS do their spacewalks etc. they could take a rubbish bag with them and collect a particle or two every time. Might take a while, but small deeds make big difference. That is at least what they told us when we were made to clean the local park at first grade.

Tags: cleanup, debris, ISS, junk, space

Category: Science thingies

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