From: Doug Jones (random@qnet.com)
Date: Thu Aug 12 1999 - 22:02:22 MDT
Spike Jones wrote:
> There are a couple of topics I am more focussed and serious about,
> such as the Mars colony. I dont want to wait for nanotech to do that!
> However, when one calculates the numbers, one ends up with
> wacky solutions that leave even extropians in stitches, or worse,
> with looks of disbelief and disdain.
Oh, it's not that bad. Zubrin's Mars Direct requires some bravery,
but not insanity, on the part of the crew. Not like the hyperbolic
rendezvous they were pushing at CFM II.
> The 30th anniversary of the moon landing made me realize I
> neglected an illustrative example. Look at the *size* of the lunar
> module. Compare it with the immensity of the Saturn V. It took one
> helllll of a mighty rocket (one which we dont have anymore) to get
> that leeeeetle spindly thing to soft land on the moon!
That leetle spindly thing massed 14,700 kg- 15 freaking tons to land
two people on the moon! With modern structures and subsystems, and
cryo propellanats, this could be reduced dramatically.
As for mighty rockets, well, that could change fairly soon. Further
I can't say, due to NDA.
> Mars is waaay farther away, (~7 months vs ~3 days) and it takes more
> fuel to soft land, since Mars has twice the gravity of the moon.
Nope- hypersonic entry and a parachute get you down to just 100 m/s,
instead of the 1700 m/s you need to back down from lunar orbit.
> Now look at the size of the Roy Wolford's Biosphere experiment.
That is not a good analogy- they tried to put all sorts of cutsie
biomes in there, instead of concentrating on the simpler task of
life support. With just chemomechanical water loop closure and
partial oxygen closure, the consumables are only about 1
kg/day/person, or a tonne per person for a 1000 day mission. No
biology other than the crew themselves.
> So, Rob, once again, I will *very carefully* and sensitively suggest
> (hoping not to generate an avalanche of canardic screeds)
> that the first Mars colony, if attempted before nanotech, will
> be require a single verrrry tiny caloric restricted woman, on a
> one-way mission, with one hell of a lot of courage and determination.
Nah- 500 tons in LEO could send a well-supplied 4 person mission to
Mars (and return). The issue isn't tech, it's money.
> Wise cracks are allowed, even encouraged, but do insert a grain
> of serious thought in reply posts, such as: how much would you
> estimate would be the weight of a reasonable minimal habitat for one
> person. Give me that, and I will estimate for you how many shuttle
> launches it would take to make that happen. spike
The key is not to use the shuttle for the project, but use large
cheap launchers developed for a different (and profitable) market.
-- Doug Jones, Freelance Rocket Plumber
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