NASA astronauts have been hitching rides on Russian rockets to reach the International Space Station since the U.S. retired its space shuttle launches in 2011.
NASA chose Boeing and SpaceX to ferry astronauts to the International Space Station within the next few years.
For the first time in four years, NASA has a new group of potential astronauts.
2011 marked the end of an era as NASA retired its manned space shuttles after 30 years in space. As the shuttles were packed off for their final resting places in a handful of museums, NASA turned its attention to the future of manned space travel and possibly trips to an asteroid and Mars.
NASA has made an out-of-this world discovery on the planet Mars. Scientists say they have found new evidence of possible saltwater flows on Mars.