The Boeing Starliner spacecraft successfully completed its uncrewed flight back to Earth, NASA announced overnight. The return ended the Starliner’s most recent flight test months later than intended and leaves its original crew, NASA astronauts Barry “Butch” Wilmore and Suni Williams, aboard the International Space Station until next year.

After their flight was scrubbed on Wednesday, four astronauts successfully lifted off, which will allow two NASA astronauts to return to Earth after an unexpected extended stay in orbit.

The crew-swap mission will enable NASA’s Butch Wilmore and Suni Williams to return home from the International Space Station.