> >Mining asteroids will, IMO, completely eliminate Earth mining.
>
>
>I may be a wimp but the idea of using the Earth's atmosphere as a brake to
>slow down a large irregularly shaped asteroid to change its orbit, as some
>have suggested, scares the hell out of me. I think there will always be a
lot
>of opposition to crashing any asteroid larger than a small bus to the Earth,
>and if they were that small I wonder if it would be economic.
The sensible versions I've read use solar mirrors to melt asteroid metals
in situ, then railgun standardised ingots to a relay station at one of the
earth-moon libration points, for redirection to earth (after, perhaps,
reshaping into lifting bodies). Still pretty scary.
Damien Broderick