james_nicoll

APPENDIX

This is what it says on the label. There are still some points of interest.



Authors: Tsiolkowsky in Russia, Bernal in England, and Cole in the U.S.A. all wrote books which bear on the concept of space colonies. Clarke, Stroud and others have also considered portions of the problem.

Tsiolkovsky is the father of astronautics (He seems not to have enjoyed much publication in English that I can find). Bernal was a pioneer in the field of X-ray crystallography (and someone whose politics led him in unfortunate directions) but the author is probably referring to The World, the Flesh & the Devil. Dandridge Cole was an engineer and futurist who wrote such works as Islands in Space: The Challenge of the Planetoids, (with Donald W. Cox) [1] but his contributions to this topic of discussion were limited by his death at age 44. Clarke is Arthur C. and I assume I don't have to explain his connection to this discussion. I have no idea who Stroud is.

A discussion of Islands in Space can be found here.

I wonder how much of my interest in this sort of thing has been driven by illustrations such as this? I wonder what that guy is pointing at?

Niven fans will note the similarity between this illustration and the habitat the Belters created so they'd have a place where women could bring kids to term (In Known Space, free fall + pregnancy = Very Bad Outcome).

Bearing forces are small, typically one ten-millionth of colony weight in one gravity.

Speaking of bearings, I've always been a bit nervous about the potential for disaster in designs that have spin-decouplers.

The goal is apparently to minimize transport costs by building cities near asteroids and then moving the cities to their final destination over the course of a generation or more. This would seem to require asteroids rich in everything a city needs. It also raises the interesting idea of what I will call for lack of a better term cities in flight, where entire communities can migrate to where the economic action is (The time scales involved may make this less than entirely effective).

Huh. Does O'Neill never discuss mass ratios? He could make the case for off-Earth resources look even better if he did that (A hydrogen/oxygen rocket could in theory produce a delta vee of 10 km/s with a mass ratio of 12. It could produce a delta vee of 2.5 km/s with a mass ratio of 1.9). He seems to be determined to avoid the apparent inefficiencies of rockets by using fixed accelerators where possible.

In PTA an estimate of 10,000 tons for lift-needs from earth to L5 was given, and 3,000 tons for transfer from the earth to the moon [...]

That would run about $6.5 billion dollars if the shuttle had actually been able to deliver material to space at $500.00 a kilo. I think the actual cost is something like 20-40 times that.

The structural aluminum considered for use in colony-building is an alloy of aluminum and silicon, the most plentiful of lunar elements after oxygen.

I assume lunar aluminum is bound with oxygen? So there will be a considerable need for electrical generation on the Moon in this scheme.

D. Criswell (ref. 5) has calculated the yields of carbon nitrogen and hydrogen which could be obtained by sifting lunar soils for the finegrained material, and then heating that material.

I'd be curious what the energy cost per kilogram of that was.

Vehicle development costs: for an advanced (non-shuttle-derived) heavy lift vehicle, estimates of development cost from within the aerospace industry vary from 5 billion dollars to 25 billion dollars; of attainable launch costs to geosynchronous, from $77/Kg to $400/Kg.

Unfortunately this was a gross underestimate.

One area requiring verification is semi-closed-cycle ecology. Many small islands have effective ecosystems more limited than that of the first colony, but verification is still required.

Any biologists care to comment on this?




1: I own this and could review it. I see a reference from Cole's grandson to an online version but I have not stumbled across that edition yet.