Wilmore and Williams, both former U.S. Navy test pilots, expected to remain in orbit for about 10 days on the mission, which was called Crew Flight Test (CFT). The main goal was to show that Starliner is ready to carry astronauts to and from the ISS, so that the spacecraft can start flying operational, long-duration missions in the near future.

As NASA astronauts Butch Wilmore and Suni Williams prepare to return to Earth after an unplanned nine months in space, here's how Boeing's Starliner mission unfolded.