RE: What are we going to do about all the space junk?

Billy Brown (
Thu, 29 Apr 1999 08:49:08 -0500

I see two big issues that are being overlooked here:

  1. Space junk is only a medium-size problem. It certainly isn't worthwhile to launch a major space program just to corral the stuff. Schemes like robotic junk-retrieval tugs will end up costing tens of millions of dollars per object retrieved, and there are tens of thousands of relatively significant objects up there. That adds up to an awful lot of zeros.
  2. There is no good reason to bother with trying to recycle the space junk. It costs more to gather a given mass together from a variety of different obits than it would to simply launch a new satellite. Furthermore, actually doing anything useful with it would require a massive (and prohibitively expensive) investment in putting manufacturing equipment in orbit. The total mass of all the junk in Earth orbit is nowhere near enough to justify that kind of investment - it might make sense as a side project if we were mining the moon or a captured asteroid, but neither of those scenarios is going to happen anytime soon.

Therefore, the question becomes one of how to efficiently dispose of the stuff. The best proposal I've seen for that is simply to zap it with a large ground-based laser. Small bits of junk (like paint flecks and drifting screws) can be vaporized this way, while larger ones can be shifted into lower orbits which will quickly decay (you do this by hitting the leading edge of the object, vaporizing part of the surface and producing thrust that slows it down). Now, granted, this is a technically challenging project, but it doesn't require any new inventions. It also has the advantage of keeping all the equipment on the ground, so we don't have to pay those exorbitant launch costs.

Billy Brown, MCSE+I