Jeffrey R. Staab/CBS
But this vision won't happen if we can't make the rockets that get us to these planets reusable, according to SpaceX and Tesla Motors CEO Elon Musk.
Currently, our rockets are of a one-and-done sort: They bring their payload up to space, but then are usually destroyed when they land back on the ground.
Musk explained why this is a big barrier to creating an interplanetary species on "The Late Show with Stephen Colbert" when asked about his company, SpaceX.
"You want to have rockets like the sci-fi rockets I was promised when I was a kid," Colbert said. Musk's response was fascinating:
This is the key to getting life to be multi-planetary is to have reusable rockets.
If you throw away the rockets every time, it's crazy expensive to go to space. But if you can re-fly the rockets, it could be comparable to air flight in its costs.
This echoes sentiments previously expressed by Musk about both space flight and the future of the human race. Here's Musk in mid-June 2015:
If one can figure out how to effectively reuse rockets just like airplanes, the cost of access to space will be reduced by as much as a factor of a hundred. A fully reusable vehicle has never been done before. That really is the fundamental breakthrough needed to revolutionize access to space.
And that should help explain why Musk's company, SpaceX, is determined to successfully land its Falcon 9 rocket on a platform in the ocean after ferrying cargo to the International Space Station. In the next few years they'll also start bringing NASA astronauts up to our home in space.
But thus far, the rocket landing has hit a few bumps. Colbert showed one of those bumps on his show Wednesday evening:
Musk, however, was unphased. When asked if it was "heartbreaking," he confirmed it was, but in a wistful enough manner that Colbert pushed him on it.
Musk said that the crash enabled his team to learn a valuable lesson in the creation of reusable rockets: "If we could reduce the landing velocity, we could get it to land and stay upright and not explode." Important stuff!
He's pretty confident that SpaceX is getting close to solving the problem; it'll have to in order to fulfill Musk's vision of bringing humans to space and back in the next two to three years.
Check out the full episode of "The Late Show with Stephen Colbert" for the interview with Musk.