From: Robert J. Bradbury (bradbury@www.aeiveos.com)
Date: Wed Dec 08 1999 - 14:27:59 MST
On Wed, 8 Dec 1999, Brian D Williams wrote:
>
> We don't have self replicating factories or Nanotechnology, and
> neither "The Case For Mars" nor "Entering Space" discusses them,
> whether or not Dr Zubrin understands them (my bet is he does) since
> neither exists yet they were not included in the discussion.
>
You have 40 trillion self-replicating factories squating on
various parts of that perform molecular nanoassembly. Three
things are missing:
(a) a way to easily program those factories;
(b) a way to get them to produce new things;
(c) a way to get them to produce things made out of inorganic materials.
You give me $10 million and between 2 and 3 years and I can solve
(a) and (b). You give me $100 million and 5-7 years and I'll
make a good dent in (c) and that is with no requirement for
diamondoid assembly. Even if I'm off by an order of magnitude
in the costs, I'd have to be *way* off in my time estimates
for you to not be seriously looking at this as a legitimate
component of any effort (be it Mars, the moon or asteroids).
This will be wet nanotech, and if you go that route, then the
requirement for water will be a concern.
> Whats the price tag on an O'Neill colony? (I'm a former L-5
> supporter)
Its on my todo list to re-examine this but the priority is
rather low. What you really want for this is self-assembly
(no nanotech required). Then you use the laser-boost
approach NASA is working on to launch self-assembling
intelligent-bricks into near-earth-orbit. When you start
being able to launch 1-10kg hunks into orbit at high
frequency without any rockets and have a resonable amount
of intelligence on those pieces then the game gets very
different. If you really wanted to assemble a Mars
shipment, this would be the way to do it.
IMO, the mistake NASA is making with Mars exploration is not
developing a standard design. Everytime you design & build
something different the costs and probabilities for failure
goes up. We are still doing space like we did nuclear power
and not learning the lessons that France has to teach about
how to do it right.
>
> Call me a romantic idealist, I don't mind....
>
Its ok, I'm one as well...
>
> No such thing, everything leaks, even the earth itself, the shuttle
> leaks like a sieve.
I could believe this, but you have to do the math and look at the
rate. If you could shelter the earth from the UV it would leak
a lot less. We *can* produce vessels that can hold a very
high vacuum, so we should be able to do the reverse (hold
atmospheric pressure) as well. All you need is technology to
heat the first few cm of whatever surface has to contain the gas
to its melting point and allow it to recrystalize (so we are back
to power).
Thats my 2c worth.
Robert
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