Astronauts Sunita Williams and Barry Wilmore returned to Earth on Tuesday after being stuck in the International Space Station for more than nine months.

Nick Hague, a fellow astronaut from the United States’ National Aeronautics and Space Administration, and Russian cosmonaut Aleksandr Gorbunov also arrived back on Earth along with them.

Williams and Wilmore were sent to the International Space Station aboard Boeing’s Starliner crew capsule on June 5 for what was planned to be an eight-day test mission.

However, several problems arose with the propulsion system of the capsule, which forced NASA to fold them into its crew rotation schedule and return them on a SpaceX craft.

As a result, Williams and Wilmore spent 286 days in space instead of the eight days that had been planned.

Hague and Gorbunov were launched to the space station in September with two empty seats on their capsule reserved for Williams and Wilmore. The four astronauts were part of the Crew-9 mission, a routine staff rotation jointly operated by NASA and SpaceX.

They departed the International Space Station on Tuesday aboard a SpaceX Crew Dragon capsule and parachuted into the Gulf of Mexico in the evening.

“We are thrilled to have Suni, Butch, Nick, and Aleksandr home after their months-long mission conducting vital science, technology demonstrations, and maintenance aboard the International Space Station,” stated NASA acting administrator Janet Petro.

She added: “Per President [Donald] Trump’s direction, NASA and SpaceX worked diligently to pull the schedule a month earlier. This international crew and our teams on the ground embraced the Trump Administration’s challenge of an updated, and somewhat unique, mission plan, to bring our crew home.”

Petro stated that “we achieve great things together for the benefit of humanity, pushing the boundaries of what is possible from low Earth orbit to the Moon and Mars” through “preparation, ingenuity, and dedication”.

NASA said that Williams and Wilmore had travelled 121.3 million miles during their mission and completed 4,576 orbits around Earth.

Hague and Gorbunov travelled 72.5 million miles during their mission, spent 171 days in space and completed 2,736 orbits around Earth.

“Throughout its mission, Crew-9 contributed to a host of science and maintenance activities and technology demonstrations,” said the space agency.

It added that Williams conducted two spacewalks and collected samples from the space station’s external surface for analysis. She also installed patches to cover damaged areas of light filters on an X-ray telescope.

“Williams now holds the record for total spacewalking time by a female astronaut, with 62 hours and 6 minutes outside of station, and is fourth on the all-time spacewalk duration list,” stated the space agency.

Also read: Before the return from space: The long road that Sunita Williams took to become an astronaut