So I guess my final question is can hydrogen be harvested from the universe?
Jupiter is said to be 89.8% hydrogen.
Saturn is said to be 96% hydrogen.
Neptune is said to be 80% hydrogen.
and of course, there are interesting compounds out there: NH3 and CH4.
You can burn both of those.
Unfortunately, the gravity on those planets is very high and conditions are harsh. It might be difficult to send a machine and bring back something.
I don't know which moon it was, but it had gigantic pools of methane and astronomers think that it even rains methane there. It should be possible to land on that moon and come back to Earth.
But if you mean getting hydrogen from space, that would be hard as the posters above me said.