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>Sorry to be so late to this discussion... it's been busy around here!
>But no one seems to have answered this question, so I figured I'd
>take a shot.

Happy to see that this is still on people's minds. Now if we could only
keep thinking about Bam, as well...

>My understanding/speculation is that one of the ideas behind using
>the moon as a launching pad is that you can be much more flexible in
>how carefully (and, therefore, expensively) you launch stuff off of
>the earth.  You can separate out the delicate parts of the payload
>for a Mars mission -- the humans, for example -- and launch them with
>great care, in an expensive vehicle with full life support,
>exhaustive safety equipment, low acceleration factors, smooth landing
>capabilities, the works.  Then you can take the rest of the stuff and
>just fling it at the moon in big, dumb, cheap, violent rockets, let
>it crash-land or bounce around with airbags, do non-human-friendly
>things to it.  Probably send up a couple of copies of everything in
>case some of it gets damaged.  Then assemble everything on the moon
>(by remote control, presumably), man the ship, push off gently and
>drift toward Mars.

Yes, that is true... but you're going to do that anyway in launching the
stuff into Earth orbit, to a certain extent. Equipment packages can be
sent into space as strapped-together bundles like self-assembly
furniture from Ikea. Then the people come out in a habitable vehicle.
People and robots put the stuff together and then you head out.

But it makes no sense whatsoever to fly to the moon, match velocity,
land, drag everything around in the Moon's gravity, kick up abrasive,
obscuring dust, and then haul yourself out of the Moon's gravity well
again. "Push off gently and drift to woward Mars" will work if you're
talking about leaving Earth orbit, but not if you're talking about
lifting off from the Moon.

It is very likely that supplies and equipment will be sent out to *Mars*
ahead of a human mission, with the aforementioned airbags and
crash-landings.

>The other (less colorful) angle of this argument is that it would
>make things much simpler to remove "able to be launched from earth,
>in one piece" from the design criteria for an interplanetary
>spaceship.  "Launching from earth" and "traveling nine months across
>the solar system in microgravity" are two completely different design
>problems, and trying to make one vehicle to do both of them would
>make it exquisitely expensive, it seems.

It has never been, not even since the days of Werner Von Braun, the idea
that we could take off in one vehicle from the surface of the Earth and
shoot in one piece to Mars. That's the stuff of Star Wars, and with any
reasonably foreeable technology is impossible. Although the gravity of
the Moon is weaker, it's too much trouble.

It's another matter if we were to build a lunar manufacturing facility
for rocket parts and fuel... but that's a very long way off indeed. For
now it makes far more sense to launch from Earth and assemble in orbit.

The moonbase (insofar as it is not simply astronautical/political
vaporware) is concieved as a research base and a very early start of
something much further down the line.

>
>Allan Ayres
>Exhibit Developer
>Lawrence Hall of Science
>University of California, Berkeley
>Berkeley, CA 94720-5200
>[log in to unmask]
>510-642-1254


Marc Taylor
Coordinator, Andrus Planetarium
Hudson River Museum
511 Warburton Avenue
Yonkers, NY 10701
(914) 963-4550 x223
Fax:  963-8558
[log in to unmask]

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