Hague and Gorbunov arrived at the station in late September, on SpaceX's Crew-9 mission. Williams and Wilmore have been in orbit since early June, when they launched on the first crewed mission of Boeing's Starliner spacecraft.

The two astronauts who crewed the Boeing Starliner greeted their replacements, who docked at the International Space Station.

A SpaceX capsule delivered four astronauts to the International Space Station early on Sunday to allow a pair of stuck NASA astronauts to return home.