Mark Whittington asks if that's what the moon will be in the twenty-first century. He also misspells Gerard O'Neill's name in the process...

I assume that he means in the energy-production aspect, not the exporting-murderous-nutballs-with-a-misogynistic-fascist-ideology aspect.

Maybe, but we're a long way from it, both in terms of the cost of getting there, and in developing the technologies to make it happen. I think that it's a race between using space for energy, and developing radical new technologies on earth that will make that unnecessary, and I don't have my money on either one right now.

Rand, your assumption is correct. And my public apology to the ghost of Dr. O'Neill for mangling his first name in print.

I'll keep my fingers crossed for fusion. It will not only create clean energy on earth, but enable really fast space travel, and prevent BP from pointing microwaves at us from the moon (I'll never be comfortable with that idea). That said, there's lots of other good reasons to go to the moon.

I suspect we'll be mining the outer solar system (Uranus, perhaps) before large scale mining of 3He on the moon occurs. If there's a big market for 3He, that means fusion reactors burning it are being produced in large numbers, which likely means we can build rockets using it, which makes round trips to the outer solar system start to be feasible (assuming you have the infrastructure to get out into space cheaply, which you must if you're serious about mining the moon.)

lunar silicon, aluminium and iron, countless square kilometers of earth-orbiting solar arrays .. theres profit somewhere in here.