Astronauts haven't launched from U.S. soil since the end of the space shuttle era in 2011. But as Russian rocketry ages and U.S. commercial and military interests grow, the ability to carry astronauts from the U.S. will be key.
The big picture: Successful commercial crew launches would be a prelude to missions aimed at deep space, including a possible return to the moon and an eventual Mars mission. Both of those are probably more than a decade away.
