I'm really sort of surprised that nobody is seriously discussing how to build a nuclear reactor in space yet. I just don't see how space civilization can get going without nuclear power. Fusion would be way cooler, but fission should do.
(Fusion would require not just that some small-city-sized installation works on Earth but that something small enough to usefully fit in other structures can generate power. We know we can put fission reactors in spaces small enough to run submarines, so that is almost certainly feasible.)
> I'm really sort of surprised that nobody is seriously discussing how to build a nuclear reactor in space yet.
Isn't the fear that this would start another nuclear arms race? I'm not sure if the threat is that much worse (considering how effective the nuclear triad is) but any perceived advantage would have consequences that increase the threat of nuclear war.
It's nuclear weapons that nobody wants in space, not nuclear reactors. Almost every outer solar system probe has had a nuclear power source that relied on decay and the Russians even put reactors on one series of satellites IIRC.
And people are working on building reactors. NASA has plans for one[1] in the 100kWe range. But mostly spacecraft have had low power needs and so people haven't wanted to deal with the complexity of a reactor.
Developing the infrastructure to take moderately enriched Uranium and enrich it to something weapons grade is likely to be outside the industrial scope of any space facility for quite a while. When we've got 10,000,000 people living on the Moon we can use the same enforcement regime as we do with small countries on Earth. Until then it's not worth worrying about.
Nuclear weapons in space can be dropped on Earth with very little warning. An ICBM has an obvious launch flare but nuclear weapon equipped satellites might be able to deploy their nukes with almost no warning.
It seems like for nuclear power to be accepted it needs to change its name like every other product using radiation or the word nuclear. One of my favorites is how Nuclear Magnetic Resonance Imaging dropped the the Nuclear. Many people now use radioisotopic instead of radioactive when they want to avoid the negative feelings around the word radioactive. Maybe isotopic power? Use it for both fission and fusion.
Notice I said both "talk about it", and "build a nuclear reactor in space". You get huge wins from any mass you can find in space, and I would imagine a good chunk of a reactor could come from space.
First we really need to capture a good asteroid, though. And have the infrastructure to turn that into useful reactor building material.
My point is not that this will happen tomorrow. My point is that this seems to me to be fundamental to any real exploration or settlement of the solar system and that anyone who is planning on settling Mars or goodness help us, Saturn or Jupiter via chemical rockets is just crazy. Sort of like how we used to do math problems on when it was worth it for some computation to just wait for next year's exponentially-better processors and start it then, anyone running with that plan is going to be beaten by the initially-slower, but way stronger plans that involve building some infrastructure in space first, rather than trying to jump straight for the flashy awesome stuff.
... of course, that also means admitting there's basically no chance that any sort of space settlement can occur in our lifetimes almost no matter what the tech advances might be, because before we can settle there's a lot of building infrastructure that lets us build infrastructure that lets us build better infrastructure to do. And somehow figure out ways to keep this all paying for itself as it goes.
(Fusion would require not just that some small-city-sized installation works on Earth but that something small enough to usefully fit in other structures can generate power. We know we can put fission reactors in spaces small enough to run submarines, so that is almost certainly feasible.)