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In lugnet.off-topic.geek, Dave Schuler wrote:
> In lugnet.off-topic.geek, Larry Pieniazek wrote:
> > In lugnet.off-topic.geek, Dave Schuler wrote:
> > > By now, everyone knows about Dubya's Brave New Vision of America's future in
> > > space, specifically regarding the Moon and Mars. One of Dubya's selling points
> > > for a permanent Moon base (perhaps modular, in 48x48 squares) is that it will
> > > make it easier to launch spacecraft to Mars "and beyond." But will it?
> > >
> > > I believe that one of the arguments is that it takes X amount of fuel to go from
> > > Earth to Mars, but only Y amount of fuel to go from Earth to the Moon and only Z
> > > amount (i.e., less than X) to go from the Moon to Mars. Dubya seems to be
> > > suggesting that, in lauching from the Moon to Mars will use only Z amount of
> > > fuel and will therefore be more efficient than an Earth-based launch.
> > >
> > > Here's my quandary: Don't we still need to transport the fuel from Earth to the
> > > Moon, and doesn't it take fuel to get there? If so, is this really more
> > > efficient? If so, it is sufficiently more efficient to justify a multi-billion
> > > dollar construction project on the Moon?
> >
> > Boost the fuel (and oxidizer) from earth?
> >
> > Fuel maybe, oxidizer no.
> >
> > The moon has among its most common elements: oxygen, silicon and aluminum
> >
> > Solar cells can be made from silicon and aluminum + trace elements. Just add
> > energy. (and technology that you brought with you)
> >
> > Rocket fuel can be made from aluminum dust. Just add energy (and ditto)
> > Rocket oxidizer can be made from oxygen. Just add energy (and ditto)
> >
> > The moon gets 2 weeks solid non stop sunshine a month, with no clouds to get in
> > the way. That's a lot of energy.
> >
> > Proposals I have seen for using a moonbase as a true BASE involve setting up
> > automated manufacturing operations on the moon... send a small plant up that can
> > make solar cells, use it to bootstrap up to a larger plant that makes solar
> > cells, use that to bootstrap up to a plant that makes rocket oxidizer and fuel.
> >
> > If aluminum dust fueled engines are too far out, you still can get a lot of
> > savings from making the oxidizer locally, even if you brought the fuel with you.
> >
> > OR... build an electric catapult to get things into low lunar orbit, then switch
> > to ion drive, which is electric (and thus non chemical and thus much higher
> > specific impulse). Aluminum ions or oxygen ions would work fine.
>
> Okay, that's pretty cool (but you lose points for using "bootstrap").
Um, no I don't. And stop resetting the FUT back to geek.
> I was
> only thinking of vehicles launched from Earth and using the Moon as a
> waystation, rather than craft built in orbit or on the Moon.
>
> But wouldn't it be monstrously expensive to build such a manufacturing facility
> on the Moon in the first place?
For NASA, sure. They blew 100B on something that could have been built out of
spent shuttle fuel tanks if they had spent about 100M early in the program.
For Burt Rutan, no. (or someone of his ilk, not trying to deify the guy but his
style of thinking is what's needed)
> Unless the moonbase is an end unto itself
It is. Divorce how it's sold from why it's a good idea.
> (rather than being solely a stepping-stone to Mars), would it be more
> economically sensible to construct a lunar base or simply to go straight to
> Mars?
Not really. Why go to Mars, exactly, at this point? We need exploitation of
space, not exploration.
> Of course, if there are other benefits to a lunar base, all the better.
There are. Been discussed in .debate before.
> But I
> guess I'm having trouble getting all the numbers to line up.
Stop thinking about having NASA do it, that will help. It makes no sense as it's
currently framed and is laughably unachievable if NASA does it. (this despite
they being about the best government agency there is). 12B will barely pay for
the coffee at the meetings where they will study whether the paint ought to be
red or blue.
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Message has 1 Reply:
Message is in Reply To:
 | | Re: We're here to go
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| (...) Okay, that's pretty cool (but you lose points for using "bootstrap"). I was only thinking of vehicles launched from Earth and using the Moon as a waystation, rather than craft built in orbit or on the Moon. But wouldn't it be monstrously (...) (20 years ago, 16-Jan-04, to lugnet.off-topic.geek)
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