Water from space

>
> On Jan 21, 2007, at 10:17 AM, cygonaut wrote:
>
> Because of shrunken areas remaining undetected, even if ice is
> found in
> these yet unknowns' darkest of the darkest of crater walls, it will
> not be
> enough for any long term moon projects or envisioned moon colonies.
>
> Dependency on water supplied from other sources is therefore
> unavoidable.
>
> How long will taxpayers tolerate such a curious predicament?
>
> George
> cygo.com
>

I think the prospect of lunar ice has always been over-hyped. It was
guessed that some lunar ice "could" be hidden on the moon, but it was
clear that 99% of the Moon is hundreds of times drier than the driest
desert on Earth. The odds of finding large amounts of lunar ice on
the Moon are so remote that it would be hard to justify an expensive
expedition just to find it. If it would cost just a few million
dollars, then I say go for it, but an expedition that costs hundreds
of millions of dollars would need to have other missions involved as
well. I also feel people are clinging to a tiny ray of hope when they
talk about finding usable amounts of ice on Mars. The poles on Mars
should have plentiful ice, but the rest of Mars will have, at best,
trace amounts of ice. The best source of ice will be comets, I
believe, and a good function for a 3rd or 4th generation space colony
would be to mine water from passing comets. Hopefully we will find
enough water on asteroids to be able to mine the asteroid belt past
Mars. The development of a cheap water mining industry to bring water
in from the outer solar system is going to be essential for space
colonization. The only other alternative is to somehow manufacture
water from other materials. I also have my doubts that this would be
able to keep up with potential demand. Long story short: I see
neither Lunar ice nor Martian ice as being of much long term aid
towards settlement of space stations or planetary colonization.
Orbiting space stations in the asteroid belt and beyond have a much
better prospect of gathering large amounts of ice.

On a related note, if we just "grab" a comet and drag it back towards
earth, it will begin to evaporate and form a tail once it gets close
to us. The Ice will have to be protected from the sun before it can
be brought back to space colonies at this altitude from the sun.
What sort of "barge" could we use to haul it back? We could use solar
wind sails to go outbound. The solar winds would push on a large
sail, pushing the barge out. But the winds only blow outwards. How
could we cheaply bring the ice back to this altitude? Would we be
better off just placing all the colonies out there where all the ice is?

doug