RE: What are we going to do about all the space junk?
Billy Brown (email@example.com)
Thu, 29 Apr 1999 08:49:08 -0500
I see two big issues that are being overlooked here:
- 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.
- 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