Thoughts on Colonization

>
> > Can't resist the temptation to nit-pick a bit, since colonization
> location is one of my favorite debates:
>
That's great. I welcome the discussion.

> >Half the time. I'd sooner get outside the shadow of any planet or moon
> than get closer to the sun in pursuit of power.
>

I don't think that Mercury's proximity to the Sun creates a problem that
can't be dealt with. That said, I wouldn't want to put an orbiting colony
any closer than that.

> > How could a location deeper in the gravity well of the sun be a way
> station to the Outer System?
>

By using gravity assist.

> To harness heat energy for power, you need a hot end and a cold end.

That's why I stated that I don't think Venus colonies can get away from
nuclear power altogether. They would have to rely on air conditioning,
which would require so much power that they would need their own grid.
Power for all other purposes can be generated by surface heat, similar to
geothermal power on Earth.

> I'm not aware of any near-term technology which would allow us to survive
the pressures or the temperatures. This is the reason why some discuss
floating cities (although I agree with you that a civilization up to that
challenge will probably already be finding orbital habitats better options).

Air-conditioned underground colonies can overcome the issue heat and
pressure. The obstacle would be the excavation itself, since we do not have
the means to be able to station people on the surface for the length of time
that would take. I'm thinking the necessary technology to accomplish that
task would be remote-controlled robots. That may not be in the immediate
future, but I also don't think it's centuries away either. We will be able
to colonize Venus long before we will be able to build Island III.

> Someone may have said this, but I'm not sure it's right. Solar storm
protons are one issue, but cosmic rays are another, and they're omnipresent.
I've heard that Mars surface habitats for long-duration living might only
need radiation shields about 1/3 as thick as for living in orbit, but that
it would be a mistake to think you don't need shielding at all.

I would like to post the website where I found that information, and as soon
as I find it, I will. You are most likely right in that some kind of
shielding is necessary. I don't think you can build a Mars colony from
materials you would purchase at Home Depot, but I don't think there are the
kinds of engineering obstacles that would exist for a Lunar or Venus colony.

> Titan is relatively benign (if we can manage to deal with a cold
atmosphere dense enough to convect away significant amounts of heat), but
Ganymede is too far inside Jupiter's radiation belts for humans to long
dwell. Callisto might be far enough outside the belts, but that's assuming
there's some advantage to being on a bigger moon, versus a smaller one even
further up on Jupiter's gravity well. I tend to think in terms of orbital
habitats conveniently close to small, mineable bodies. So from that view,
the outermost, mountain-sized moons might come closer to being economically
developed than a large Galilean moon.

I agree that because of Ganymede's location in the radiation belt poses a
problem. But unlike on Europa, where the radiation is so great that even a
quick surface landing would be deadly to humans, I think that Ganymede
colonies can be constructed in a way that shields radiation. This requires
engineering that is beyond my ability to speculate, but I tend to think it's
theoretically possible. I don't think the moonlets are good targets for
colonization. I stated my concerns about microgravity. Nanogravity is a
whole different beast. I question whether anyone would want to live in a
near-zero-g type of environment, and I definitely think there would be
long-term health risks. However, that doesn't mean that permanent bases
manned with staff that works rotating shifts of a few weeks or so isn't
feasible.

> But it needs to be burned with oxygen. Yes, I'm certain Titanians would be
manufacturing oxygen, but I doubt they would be doing it for heating their
homes. I think the energy costs of obtaining the oxygen would make it
uneconomical for just heating. I'd say nuclear reactors would be a safe bet
for Titan. The dense atmosphere would be a convenient heat sink for the
exchangers.

I have to say you're probably right about that.

> But I agree with you completely about the advantages of orbital colonies,
and that terraforming will probably prove to be unnecessary.

Yes, between floating colonies and orbiting colonies, I would definitely go
with the latter. Floating colonies make me think of ships floating on air.
If you've ever been on a ship in rough seas, you know it can be an
unsettling experience. I don't think colonists would appreciate the
equivalent of daily earthquakes.