Since the launch of Sputnik in 1957 we’ve launched tonnes of stuff (literally) into space. We’ve not kept things very tidy up there either, so we now have hundreds of thousands of pieces of junk orbiting around us, threatening to crash into important things like the International Space Station. Or the satellite that handles your TV signal. These range in size from entire defunct satellites, to tiny coin-sized bits (there was even an astronaut’s tool bag for a while). How should we deal with all this mess? Shoot it with a laser of course!
It’s actually a pretty simple idea – laser pulses fired at a piece of debris act as a force which slow it down, thus changing its orbit and eventually making it fall into the atmosphere and safely burn up. It was first proposed 15 years ago but it’s only recently that technology has advanced to a stage that it could be built. I’m imagining that it will look something like this:
(Image from Flash Gordon and borrowed from Thiel-A-Vision)
but the authors of a paper published on the astronomy arXiv today disappointingly have something more like this in mind:
They also note that a project like this would need international co-operation before it could be built. I thought that this was because it would be a complicated thing to construct, but on closer reading it turns out to be a more fundamental issue. It’s to
…avoid concerns that it is really a weapons system.
Probably another good reason not to go with a Flash Gordon inspired design. Still, however it ends up looking, it should be a major help in cleaning up our astronomical mess.
Claude R. Phipps, Kevin L. Baker, Brian Bradford, E. Victor George, Stephen B. Libby, Duane A. Liedahl, Bogdan Marcovici, Scot S. Olivier, Lyn D. Pleasance, James P. Reilly, Alexander Rubenchik, David N. Strafford, & Michael T. Valley (2011). Removing Orbital Debris with Lasers Advances in Space Research arXiv: 1110.3835v1