Astronauts Suni Williams and Butch Wilmore are back on Earth after spending nine unplanned months in space.

They departed the International Space Station (ISS) early on Tuesday morning and splashed down off the coast of Florida after a journey of 17 hours.

Boeing’s Starliner, their original return spacecraft, was deemed unsafe for the journey home, forcing the astronauts to stay in space much longer than planned.

They had travelled to the ISS on board Boeing’s CST-100 Starliner as part of its first crewed test flight. The mission, under NASA’s Commercial Crew Program, aimed to develop private spacecraft for transporting astronauts to and from the station.

By outsourcing low-Earth orbit missions, NASA has said it aims to focus on deep space exploration, including the Artemis missions to the moon and future human missions to Mars.

During the 25-hour flight to the ISS, Starliner experienced helium leaks and a malfunctioning thruster, which helps steer and control reentry. When it arrived on June 6, four more of the 28 thrusters failed, delaying docking with the station.

Although engineers restored four out of five failed thrusters, NASA deemed the spacecraft too risky for human travel and sent it back empty, leaving Williams and Wilmore stranded on the ISS.

In August 2024, NASA decided to bring them back on a SpaceX vehicle. Crew Dragon-9, which launched on September 29, 2024, has been docked at the ISS since, but bringing them home earlier would have left only one US astronaut on the space station, limiting research and emergency response.

With their replacement members arriving on Crew-10, Williams and Wilmore were finally able to head home.