The Crew-10 astronauts must arrive at the International Space Station before Williams and Wilmore, who are currently assigned to the Crew-9 mission, can complete their rotation on the orbiting laboratory and head back to Earth.

NASA on Tuesday swapped out the astronaut capsule it plans to use for an upcoming routine flight to the International Space Station, a scheduling move that will allow a slightly earlier return for two Starliner astronauts who have been on the station far longer than expected.