Let's get back in space

Since going to the moon, we've done very little in space. This doesn't seem too unreasonably, since space doesn't have that much to offer us. Yeah, there are some resources in greater abundance on the moon and mars, for example helium-3, a potential fuel source for nuclear fusion, is very rare on the Earth, but very common on the moon. But we can manufacture helium-3, and it's cheaper than going to the moon to mine it. I don't think there are any resources that it would cheaper to get from space than from here.

So, what's the point of going out? Personally, I would rather the human race not go extinct. The Earth will be hit by asteroids. Even if they're not mass-extinction size, they would still cause massive catastrophe. Don't keep all your eggs in one basket. Even we get incredibly lucky and we aren't hit by any asteroids, the sun will die, and it will take Earth and Mars with it. That'll be four or five billion years from now, so hopefully we can make some colonies in Alpha Centauri or Tau Ceti by then.

But if we're ever going to get out of this system, we're going to need to research better propulsion techniques to get us there faster and cheaper. And then we'll need the technology for either cryogenic storage of living humans or that of a fully self-contained system capable of supporting a large number of humans for an indefinite period of time.

And to do that research, we need to get out there.