on Tue, Oct 02, 2001 at 05:19:09PM +0100, Ken Brown (k.brown@ccs.bbk.ac.uk) wrote:
Once the catcher is high enough it ought to be possible to set the launcher so that missed catches zip round Earth & head out. After all, at Lunar OV it "wants" to be in a high orbit. Achieving re-entry through Earth's atmosphere - sorry that should be "entry" it wasn't here in the first place - needs some precision.
The Heppenheimer book cited here previously posited a catcher fabricated out of bulletproof material, in lunar orbit. Of roughly conical form, and rotating about its axis, material launched via railgun from the lunar surface would be caught, then ferried to an L4 or L5 construction point. Heppenheimer's scenario envisioned using pellet shooters as reaction mass. Matter flux in orbit is such that operations could be carried out for extended periods of time with no perceptable increase in micrometeorite impacts.
And if the loads are anything smaller than a large truck, they ought not to harm Earth anyway. Just a pretty light show for anyone watching the skies. Nothing like as fast as natural meteors.
For loosly aggregated masses, possibly even larger: they'd simply disintegrate in orbit. Though try to justify the low odds to the poor sap who *does* happen to be in the wrong place.
Anything big enough to do damage on Earth will be visible from Earth.
Lunar material has an albedo of about 3%. Its radar signiture may be better. But there isn't currently a tracking system that's designed to detect large amounts of new orbit insertions. Yes, we track dead satellites, lost space hardware, and the odd glove. Hundreds of thousands of stone-tossings, I'm not so sure.
So it isn't at all a useful weapons launching system. If you are trying to drop big hot rocks on cities, they will have time to run away (low tech solution)
Cities can't run. Their populations can. But it would take a day or two for a typical US conurbanation. The infrastructure remains particularly vulnerable. Better yet: water strike. If you're particularly devious, aim for an unstable undersea slope seismic region. Heinlein's good history here, particularly if you're into harsh mistresses. Peace. -- Karsten M. Self <kmself@ix.netcom.com> http://kmself.home.netcom.com/ What part of "Gestalt" don't you understand? Home of the brave http://gestalt-system.sourceforge.net/ Land of the free Free Dmitry! Boycott Adobe! Repeal the DMCA! http://www.freesklyarov.org Geek for Hire http://kmself.home.netcom.com/resume.html [demime 0.97c removed an attachment of type application/pgp-signature]