SpaceX is poised to launch its first astronauts into space this spring: Bob Behnken and Doug Hurley.

Their flight on the company's Crew Dragon spaceship will mark the first time an American spacecraft has carried NASA astronauts since the Space Shuttle program ended in 2011.

Behnken and Hurley's liftoff is expected to launch a new era of US spaceflight, since it will allow NASA to stop relying on Russian launch systems to get astronauts into space. It will probably also make the two astronauts the first to ever fly a commercial spacecraft.

"Bob and I were lucky enough to be selected together," Hurley told The Atlantic in September. "As we get closer to launch, things in the last year have actually been pretty hectic. We've been spending increasing amounts of time in California, because that's where most of the work is being done for Dragon."

In preparation, they've run through emergency procedures, undergone extensive training the Crew Dragon's mechanisms, worn their new spacesuits, and met with SpaceX CEO Elon Musk.

"People to a degree think it's pretty glamorous to be able to go into space, but it's actually like a messy camping trip," Hurley told Reuters in June.

Here's how the astronauts were selected and how they're preparing to fly Crew Dragon to the space station.