Re: ...Nasa/Griffin LYING about Public Support for Moon/Mars Missions!

John Schilling wrote:

A magnetically-shielded Stanford Torus, would mass roughly one
million tons and house roughly ten thousand people. So, 100 tons
per person. Assuming habitat mass and SPS mass are of roughly
equal cost and complexity, this means housing one person in a
settlement in cislunar space, would cost a bit over two million
dollars per year.

Do you fundamentally disagree with any of those numbers? Some
of the underlying assumptions are, IMHO, rather conservative.
Part of the cost of SPS electricity will go to groundside ops,
for example. But even with the conservative assumptions, the
existence of economically viable solar power satellites implies
the ability to support classic "space colony" architectures
at a cost of ~$2E6/person/year.

How many round trips to GEO, were you expecting to buy for that
price?

Some comments...

Only a fraction of the cost of building that space colony can
be the cost of moving its material into place. So your scenario
includes the assumption that moving large masses around in space
is very cheap. A person weighs much less than 100 tons, even with
spacesuit, so the cost of moving that person to GEO should be
much less than the cost of moving 100 tons to GEO, which in turn
should be only a fraction of the cost of the space colony allocated
to this worker.

How expensive will it be to rotate to Earth? The obvious way to do it
is with shielded cyclers in elliptical orbits from LEO out to near GEO
(probably on an orbit with a period a rational multiple of a day).
The actual mass accelerated from the surface to LEO, from LEO to
the cycler, from the cycler to GEO, and all back again, need not be
very high. Assming you can get the reaction mass for the in-space
parts from ET resources (just as you are likely assuming you can
do for SPS and space colony construction), the cost could be dominated
by the cost of launch to LEO. I expect this would be much lower
than today's launch costs, else none of this would be happening.
If the cost is 1% of the cost to launch to ISS, that's $.2M/person/rotation.

Permanent placement of the people in orbit will also require permanent
placement of their *families* in orbit, as well as auxiliary personel
(teachers for the children, for example). This could easily inflate
the population by an order of magnitude if not more, for a given
set of workers. If you don't put the families there, you have to
rotate the people periodically.

Paul

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