Re: A case for the eradication of unmanned Mars missions

Robert J. Bradbury (
Wed, 8 Dec 1999 09:30:42 -0800 (PST)

On Wed, 8 Dec 1999, Brian D Williams wrote:

> From: Eugene Leitl <>
> and yet in less than a decade, it was developed, and the mission
> completed successfully. JFK was a man of vision, nixon was not.

I question that, watching the recent PBS series on space, I became pretty convinced that the entire effort was due to the fact that the Russians were kicking our pappoochka in space.

It was a fight to justify the good 'ole democratic system.

I'm also not sure that Nixon could be viewed as non-visionary. Though, perhaps Johnson started it, I think Nixon gave a big boost to the "War on Cancer". He also gets credited with normalizing relations with China. It wasn't that he didn't see things its just that his priorities were different.

> >You have strange notions about being "not particularly expensive".
> >I'm reasonably certain that we could now make a self-rep lunar
> >factory on a 30 G$ budget, perhaps even less.
> The notion of "Cheap Power from space" has been thoroughly
> discredited, see Robert Zubrins "Entering Space" for details.

Though I haven't read "Entering Space", I would strongly question his analysis. You also aren't discussing the same point here, Eugene's comment is on self-rep lunar factory (now the devil is in the details because the critical factor is the doubling time). The benefit here is *not* in power but in the fact that you have self-replication. Self-replication (if its fast enough) makes everything "relatively" free.

I strongly doubt that Zubrin understands either self-replication or nanotechnology sufficiently to *discredit* "Cheap Power from Space". All he can possibly do is point out that using current technologies it isn't going to be "cheap". I mean really now, quoting Zubrin as a source on this list? For heaven's sake this man wants to *colonize* something at the bottom of a gravity well. That means you are going to have to pay through the nose every time you want to go someplace else or ship something. Give me exclusivity on the Mars to Earth FedEx route and I'll show you a rich man.

The idea of "colonizing" a planet has been discredited since O'Neill showed it was entirely unnecessary. I think Greg is right, that the Mars folks are a bunch of romantic idealists in love with their pipe dreams.

> I'd like a little bigger reserve thanks, besides most industrial
> processes use large quantities of water. Undoubtably we will devise
> new processes since water will be more expensive, we can sell these
> technologies back to earth.

Since you have to have a completely sealed environment anyway (otherwise your atmosphere leaks out) you are never going to lose any H2O. So you can get buy with a lot less than you need in an Earth based environment. With colonization you are going to need power, lots of it, and for that the moon is better.

> >You're still dead if there's a decompression. You still leak stuff
> >outside and have to continuously replace it. But you cannot launch
> >anything with a mass driver from the surface, with the possible
> >exception of the top of Olympus Mons.

Eugene, I don't think thats accurate. If you've got calculations I'd like to see them. NASA is studying mass drivers to assist launching on Earth, so I would think they have to work on Mars. The question comes down to whether the friction limits launch speed to sub-orbital rates, in which case you need rocket assists.

> >Mars should be a second
> >step. If you have the Moon, Mars is easy. Not vice versa. And you
> >can't do both, it's too expensive.

If you did self-replication here on Earth first, you could do them both very quickly and very cheaply...

> >> I have nothing against the moon, it will make an interesting
> >> place to have an observatory, but Mars is a place we can live.

So is space itself. In fact sometime in the next couple of years we will have people doing just that.

Its worth noting that most of the arguments for Mars *or* the Moon work for Near Earth Asteroids as well (they have lots of raw materials, etc.) and don't have the disadvantage of a deap gravity well.