The four newcomers will spend the next few days learning the station’s ins and outs from Butch Wilmore and Suni Williams. Then it will be time for those two to end their nine-month stay and head home.

America is eagerly awaiting the return of two astronauts who have been stuck on the ISS since last June. Here's who they are.

A SpaceX capsule delivered four astronauts to the International Space Station early on Sunday in a NASA crew-swap mission that will allow a pair of stuck astronauts, Butch Wilmore and Suni Williams, to return home after nine months on the orbiting lab.