In article ,
Terry Goodrich wrote:
why not set a couple of landers containing robotics (dirt movers). One
would be backup in case of bad landing and both would carry homing beacons
to guide sample modules to the same spot. This would carry the advantage of
being able to decrease the return modules payload down to 5 kilos or so...

I'm not sure where the advantage would lie. There's no need for precision
landing capability at all, if what you're selling is simply rocks. The
guidance requirement for landing is driven by the need for soft landing,
not precision landing.

spread the return payload over the next 8 flights so the failure of one
flight would not kill the profit for the whole thing...

A failure is, if anything, more likely to be in descent than in ascent.
Ascent is a lot simpler.

1. Could a guidance beacon or possible a laser reflector provide enough
guidance for the landing modules to land close enough for this to work?
(Precision guided munitions seem to be able to do this within a few meters).

It's not *quite* that simple, alas, not without adding quite a bit of
hardware to each lander. But there are ways it could be done, if there
was a use for it.

2. Could the orbital GPS system possibly help with guidance? Would it have
the range?

GPS is pretty nearly useless beyond LEO. The GPS satellites do not
broadcast in all directions; they beam their signals at Earth. So you get
continuous coverage only if you are on or very near Earth. (There are
things you can do with the limited and intermittent coverage at higher
altitude, which comes from spillover past Earth, but it's not very useful
for real-time guidance.)

3. As a comparison what would be the relative worth of moon rocks compared
to diamonds gram for gram? ( I would love a tie pin set with a 10 or 20
carat moon stone)

Really, nobody knows for sure. It depends very heavily on the size of the
market, which is almost unknown.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |