You can invest in SpaceX indirectly and directly. You have SpaceX indirectly through some mutual funds and actually through Google since Google’s VC arm invested in SpaceX. I have a tiny bit in those two via a mutual fund and Google. The problem is both have SpaceX as a very small percentage of their portfolio. There is also Virgin Galactic but I don’t have that.

One material Robert Zubrin is interested in is a rare form of hydrogen. He thinks that it would be a good candidate for fusion if we ever figure it out.

Do you perhaps mean Helium-3? The only interesting rare form of Hydrogen is Tritium, and Tritium is rather nasty stuff.

You are right.

> they aren't intrinsically valuable

perhaps not, but materials in space can be assembled to functional components in space. functional components beget more things happening in space.

> remove the dependence on them

cool. you can beam electricity from space, too...