From: Spike Jones (spike66@ibm.net)
Date: Sat Apr 03 1999 - 00:34:20 MST
> Spike Jones wrote:
> > The minimalist approach requires no technology that we dont already...
> Bartley R. Troyan wrote:Do you really think that the cost of sending one person to
> raise a group of 10-20 kids from embryos all the way to a productive age (early
> teens?), is lower than the cost of getting 10-20 adults and the stuff
> they need to survive and thrive to mars?...
Bartley, that is a goooood question. I went at this problem strictly from
a propulsion engineer's point of view, with little regard for some of the
more practical difficulties. Some of the payload scales to the size of the
crew, and some of it does not. For instance, the food requirements are
directly proportional to the size of the crew. Same for water and waste
recycling facilities. The size of the habitation module might not be
directly proportional to the size of the crew.
Consider pressure vessels: suppose you develop some type of plant
that grows in liquid water under artificial light. You need to maintain
the vapor pressure of water at, say 20C, plus some margin. I imagine
you would be in the neighbor hood of 10 to 20 kilopascals against
an outside pressure of about 2 kPa. Nowthen, a pressure vessel's
mass is directly proportional to its volume, given constant pressure.
Reasoning: the volume of a given container increases as the cube of
its linear dimension. The surface area increases as the square of
the linear dimension, however, for a given pressure requirement,
the required thickness of the vessel increases directly proportional
to the linear dimension. Therefore, the mass of an ideal pressure
vessel is proportional to its volume. So, twice the crew, twice
the required mass of a farm module.
> I don't know if even the most
> motivated single mom is going to have time to grow/manufacture the food
> they all need...
Ah, but would she not be highly motivated? {8-] You may be right.
Read on:
> ...repair the odd broken solar array...
She may be highly dependent on semi-autonomous robots, controlled
mostly by earthlings.
> ...chase toddlers...
Chase them where? I expect the hab module to be quite small.
Her biggest challenge would be maintaining her sanity, assuming
a child raised in a space about equal to a good sized motorhome,
when neither can go outside and play, at least not for long.
> ...play with and read to these kids so they turn out intelligent...
Problematic for sure, but when all is said and done, it is not clear
to me that the first native generation will need to be all that intelligent
in the traditional sense. They need to use their brains for one
thing: surviving in a hostile environment. Even still, I suspect
most of their education will come in the form of signals from
the home planet. Do they need to learn how to read? Why?
Do they need to be able to work on machines? Absolutely.
> ...Wouldn't it be cheaper in the long run to send a group
> of somewhere from 10-50 young adults (maybe some teenagers, sure)?
OK, but before you go too far down this road, try to imagine
what manner of spacecraft would be needed to carry off such
a thing. Is the craft assembled in earth orbit? After how many
launches? On what launcher? At what cost? Ten people soft
landing on Mars requires an awesome payload.
>...The hardships faced being the first (and only) adult human living
>on another planet's surface seem to be more than one person could handle....
Again, you may be right, but consider the fact that we humans
can be tough daughters of bitches. Back in the old days trappers went
into the interior of America, and saw not another human for
two years. Prisoners have been kept in solitary, with no books
and no nothing for years, and somehow managed. Island of the
Blue Dolphin: story based on reality. Young lady lived alone
for 12 years on a small island. The single Martian, even without
reproductive success, would have constant interaction with humans,
with only a maximum of 20 minutes delay in communications,
minimum of about 2 minutes.
> What if mom gets cancer and dies suddenly--what happens to all the
> kids?
Depends on their ages. If the oldest child were at least
8 yrs, they might make it anyway. Children can be quite resourceful
if they need to be. Younger than that, they all die. Sad indeed. Im
not claiming this is a low risk adventure.
> What if she breaks an arm?
Or leg? This would bad, but unlikely in 1/3 G. Landing is high
risk for sure, but it only gets more difficult as the lander gets
larger. It is easier to land a Cessna than 747.
> > So again, I am back to: how small could the mission be scaled? spike
>
> Not *that* small.
OK, but how small? Im thinking the single astronaut, one way trip
*might* be doable for about 5 billion dollars, ($5E9) assuming
some of these low cost outfits like Kissler Engineering are successful
with their low cost commie engined boosters. Im thinking you would
need to soft land about 80,000 kg on Mars to give a single small
astronaut a fighting chance, by which I mean about ~5 yrs of processed
stored food to last until a farm module could be built from
indigenous materials and operated at break-even, plus a small
nuclear reactor, semiautonomous robots to build the farm
module, a small foundry to process materials, a solar cell
production facility, etc.
5 billion is in the neighborhood of what could be raised
by enough fanatic rich people. It is two orders of magnitude
cheaper than NASA estimated for a three-man flags and
footprints mission, but that effort assumed a way home.
> ...Are ya listening, Bill G.?
uh, no. Hes preoccupied at the moment. {8-[ In trying to
brutally slay any firm that presumes to develop software
anywhere other than in Redmond Washington that runs
on any platform other than windows. I would be
surprised if Mr. Gates has any ambitions to do something
like this. Of course, I might be wrong. Hope so. spike
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