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The Orbital Junkyard

Space junk

New technology can warn whether a piece of junk poses a threat to a spacecraft, and if so in which direction the craft should move.

By Stephen Luntz

Satellites are under threat from about 500,000 pieces of space junk, but new Australian technology can now track the orbit of debris as small as 1 cm to within 1 metre.

The full text of this article can be purchased from Informit.

Far above our heads, even above the ozone layer, the Earth has a pollution problem. Low Earth orbit is becoming increasingly crowded. Not only are satellites ever more common, but they face more and more danger from pieces of space junk.

However, Australian company Electro Optics Systems Holdings Limited (EOS) thinks it has a big part of the answer. For a country that, to a large extent, has turned its back on space research, this could become our major contribution.

The Problem
In addition to 500–600 operating satellites, tens of thousands of pieces of junk are circling the planet. While most are small, the speeds at which they are travelling make them dangerous.

So far one major collision has occurred, in 2009 between Iridium 33 and the deactivated Kosmos 2251. At a speed of 11.7 km/s, the accident unsurprisingly destroyed both satellites.

The great danger with such events is that they will unleash a cascade. In a collision each object is likely to break up into numerous components, many of them large enough to cause future collisions. More than 1700 pieces of debris have been catalogued from the Iridium/Kosmos collision, but that number is incomplete. So far none appears to have triggered their own collisions, but it may be only a matter of time. Moreover, the lack of a cascade from one event does not mean that such...

The full text of this article can be purchased from Informit.