Two NASA astronauts who were stuck in space for over two months will return to Earth with SpaceX in February 2025.

NASA said the Boeing Starliner spacecraft that carried astronauts Sunita Williams and Barry Wilmore to the International Space Station (ISS) will return to Earth “unmanned.”

The pair launched on June 5 on what was planned to be an eight-day mission, but will now spend about eight months in orbit.

On the way to the ISS, the Starliner encountered problems, including a leak of helium, which pushed fuel into the propulsion system. Several engines also did not work properly.

Boeing and SpaceX both received billion-dollar contracts from NASA for commercial space flights of its astronauts. Boeing’s contract was worth $4.2 billion (£3.18 billion), while SpaceX, founded by billionaire Elon Musk, received $2.6 billion.

SpaceX has completed nine manned flights into space for NASA, as well as several commercial missions, but this was Boeing’s first attempt at a manned mission.

Engineers at Boeing and NASA have spent months understanding the technical issues surrounding the Starliner spacecraft.

They conducted tests and collected data both in space and on Earth, hoping to find the cause of the problems and a way to return the astronauts safely home on the Starliner.

At a press conference on Saturday, NASA Administrator Bill Nelson said Boeing is working closely with NASA to determine what improvements need to be made to the spacecraft.

“Space flight is risky even in its safest and most routine forms, and a test flight is by its nature neither safe nor routine,” he said.

“Our core value is safety and it is our guiding star.”

It was decided to extend the couple’s stay on the ISS until February 2025 so that they can return on a SpaceX Crew Dragon spacecraft.

The extra time will allow SpaceX to launch its next vehicle, which is scheduled for late September.

The spacecraft was originally scheduled to carry four astronauts, but instead two will fly to the space station, leaving room for Mr Wilmore and Ms Williams to return to Earth in the vehicle at the end of the planned mission next February.

NASA said both astronauts had previously completed two extended stays in space and were aware of the risks of the test flight, which included staying on board the station longer than planned.

The organization said Wilmore, 61, and Williams, 58, were “fully supportive” of plans for their return and would spend the next few months conducting scientific work, performing maintenance in space and possibly some “spacewalks.”

The launch of Boeing’s Starliner had already been delayed by several years due to setbacks in the development of the spacecraft. Previous unmanned flights also encountered technical problems.

Boeing said in a statement that its focus remains “on crew and spacecraft safety.”

“We are conducting the mission as defined by NASA and preparing for a safe and successful unmanned return,” it said.