Rory wrote a post about strong AI and whether we should spend money there rather than going back to the moon. I started writing a comment for his blog, but then decided to write my own entry.

I don't know if you were around during the 80's, but there was a big push towards AI during that decade. The buzz was that the Japanese were going to "eat our shorts" (though I'm fairly sure that phrase was yet to be invented) in this area.

There was a lot of money spent there (perhaps not $15B, but my guess is that it might have been $1B), but very little result.

I think it's because AI is just a very difficult problem.

To comment on the space side, scientific exploration aside, I think the best goal to push for is solar power satellites. There are some PR issues (with microwaves), but the technology is well understood, and once they were there, using them as a source of power would have very little environmental side effects (though waste heat would still seem to be an issue). I don't see how the developing countries can become developed without huge increases in total energy consumption, and the only other reasonable option is nuclear. Nuclear has very low environmental impact and is cheap enough if done well (and we know how to do it well, though we haven't yet), but is a very hard political sell, both from the "no nukes" perspective and the prospect of further nuclear proliferation. On the other hand, if a country like China (which already has nukes) wants to build reactors, I think we should do our best to help them build good ones (like this or this), and we should consider whether we can make a reactor proliferation proof. But, back to the space topic...

Indirectly, I do think that building SPSs makes an argument for going back to the moon. The big problem with SPSs is the huge expense in building them. The issues are:

  1. Photovoltaics are expensive
  2. Launch costs are astronomical (pun intended).

There are starting to be some approaches to #1 that may yield lower cost cells, but they aren't quite there yet. You could use something else for #1 (like a solar furnace), but that seems more finicky to me.

The second problem is harder to solve. You can like get a 10x reduction over current expendables if you go simple and you launch all the time. You might get a lot more with a space elevator (assuming that you can truly build one). But the simplest way is to not lift from the earth, but to mine lunar materials, and build the SPS components either on the lunar surface or in space.

Problems? Well, you would have high-tech with people in an extremely remote and expensive place to get to. That would require some very smart planning.