On Fri, 2 Aug 2002 13:21:03 -0400 (EDT), Henry Spencer
<[EMAIL PROTECTED]> wrote:
>I agree that an extra km/s or so of delta-V makes the system more
>versatile, more capable of tackling last-minute missions. But how
>important that is depends on the requirements, in particular on whether
>the job is to reconnoiter asteroids selected on some other criterion
>(e.g., future impact probability) or just to reconnoiter a sampling of
>asteroids. In the latter case, you can pick the convenient ones; in
>the former, you need as much flexibility as you can get. Even there,
>though, some recon capability is better than none.
If the job is recon, you also want to look at how well the
"competition" can do the job. Radar astrometry is much more accurate
than visual astrometry, and can also characterize the shape, rotation
period, rotation axis, and surface texture better than any but the
closest flyby. And it's cheap.
Flyby missions would go to rocks that radar can't see (too far away or
too far south). Of course, there are things radar can't do... Taking
a picture just as you passed the terminator 1000 meters away would
prove that you had the accuracy and timing down to use a nuke to nudge
the rock a bit to the side.
(A gentleman who shall remain nameless once proposed an impact fuse
for the nuke. I just looked at him. "What?" "What's the closing
speed?" "20 or 30." "How fast does an impact fuse work?" "Oh." :-)
-R
--
"Sutton is the beginning of wisdom -
but only the beginning."
-- Jeff Greason
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