Starliner: Nasa delays return of astronauts stuck in space again

Suni Williams and Butch Wilmor travelled to the International Space Station (ISS) on 5 June, expecting to return after eight days.

But the Starliner craft ran into trouble when five of the spacecraft’s thrusters, which help it manoeuvre, cut out on the approach to the ISS. Helium gas, which pushes fuel into the propulsion system, also leaked.

The problems mean Ms Williams and Mr Wilmore have to remain on the ISS while engineers carry out a high-level technical review.

One alternative way for them to return home is using a SpaceX craft leaving in autumn. More likely, they also could travel on a SpaceX flight early next year.

The latter would turn an eight-day mission into eight-month trip.

It is not a simple task to change how the astronauts travel back to Earth.

Officials said on Wednesday that the astronauts’ space suits are not interchangeable. If they returned on the earlier SpaceX flight, they would travel without Space X-specific suits, which could pose additional risks to them.

If they traveled on the later flight in early 2025, there would be time to deliver the appropriate suits.

Simeon Barber, a space scientist at the Open University, told BBC News that either way, it seems “we are heading inexorably towards a return on Space X’s” crafts.

“It seems that there are decision-makers at Nasa who are unconvinced that a safe return can be guaranteed,” he said.

Boeing has said repeatedly that it has full confidence that Starliner can bring the two astronauts safely home.