Thoughts on Colonization

From: Dave Powell

> I don't think that Mercury's proximity to the Sun creates a problem
> that can't be dealt with.

I don't either. I was just saying that between getting outside of the shadow of celestial bodies, and getting closer to the sun, the former is more advantageous for baseload power generation in my opinion.

> That said, I wouldn't want to put an
> orbiting colony any closer than that.

I don't think there would be any particular advantage to placing orbital habitats that close to the sun, but I don't think there would be any particular technical problem with it either. If we've read O'Neill, we know that habitats can orbit further from the sun if we make the mirrors bigger, and slightly concave, to concentrate the sunlight. By the same token, I think you could have habitats orbiting closer with somewhat smaller, convex mirrors. But between easy availability of volatiles, and saving a bit of money on your mirror budget, I think the former is far more economically impactful, and thus expect more-distant habitats to predominate.

> By using gravity assist.

There are two kinds of gravity assists. One depends on moving planets (like Jupiter), the other depends on fueling up high in a gravity well, and then burning the fuel much lower in the well. I don't think either would apply to colonies closer to the sun.

> They would have to rely on air conditioning, which would
> require so much power that they would need their own grid.

Air conditioning also needs a cold end. Where is the heat sink on the surface of Venus?

> Power for all other purposes can be generated by surface heat,
> similar to geothermal power on Earth.

Geothermal works on Earth because there can be a hot end (underground) and a cold end (on the surface). As far as I can tell, the surface heat of Venus is unusable for power generation.

> Air-conditioned underground colonies can overcome the issue heat and pressure.

When going underground, you have to contend with more heat and pressure, not less.

> We will be able to colonize Venus long before we will be able to build Island III.

I disagree. The technologies (if not the operational systems) to build Island III exist right now. A technology allowing us to withstand such heats and pressures as exist on Venus do not yet exist.

> I don't think the moonlets are good targets for colonization.
> I stated my concerns about microgravity. Nanogravity is a
> whole different beast.

Remember that my speculation was about O'Neill type habitats orbiting adjacent to small mineable bodies. I thought such small moons might get economically developed, but agree probably not colonized on a large scale.

> 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.

I'd never before stopped to think about what turbulence might feel like in a floating city. I wonder if the Venus city promoters have tried to address this issue.

Regards,

Mike Combs