Re: the case for Mars (was the case for the eradication of unmanned

Robert J. Bradbury (
Wed, 8 Dec 1999 13:27:59 -0800 (PST)

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.