Machine City, in the sky (was The single-shell city can be done now)

> No, that is not what I meant. I was referring to a functioning
> local-economy after construction and move-in. OK. I think I have the same problem with your scenario which I had with that of Marshall Savage (The Millennial Project). He came up with ways for space settlers to make a living which could be done in space just as easily as on Earth. But I don't think that's sufficient. O'Neill felt that he had to come up with some product or service that was better done from orbit than from any location on Earth. He posited the construction of SPS from space materials. To this day, that's the business plan which still makes the most sense to me. > In spite of that, it is
> more competitive, cleaner and safer than any other
> power-generation type, except hydro. My personal beliefs are that technically speaking, nuclear has a lot going for it. I think its problems are mostly political. But because of those political problems, I'm not the nuclear advocate I was in my younger years. > There is no essential reason to decom a reactor unit anyway,
> since they do not wear out. My understanding has been that neutron bombardment results in the embrittlement of parts. > China is going for the PBMR in a big way. This is one reason I
> figure that HyOx fuel for Pacific-equatorial launch platforms
> would be essentially free.
I don't think a conservative business plan should assume that anything can be essentially free.