First, only two people rode into orbit on SpaceX's Crew Dragon spacecraft, rather than the usual complement of four astronauts. This mission, known as Crew-9, originally included Hague, Gorbunov, commander Zena Cardman, and NASA astronaut Stephanie Wilson.

The SpaceX Dragon, selected by NASA to transport astronauts Suni Williams and Butch Wilmore home, arrived Sunday at the International Space Station.

It's SpaceX to the rescue after NASA officials made a tough safety call to send Boeing's Starliner spaceship back to Earth without its two astronauts.