crewed

They were taking part in the first crewed test flight of the Starliner spacecraft, which was developed by aerospace company Boeing.

Dr McDowell suggested it could take many more years for Starship to be ready for a crewed mission to the moon, which could begin to be "very embarrassing thing for Nasa to navigate".

A ship the size of a football field, crewed by more than 50 engineers and technicians, cruises the oceans around Africa to keep the continent online.

The next crewed mission will see four astronauts fly around the Moon in 2026.

Meanwhile, SpaceX was awarded a smaller contract to develop a crewed capsule, based on its existing Cargo Dragon capsule, and that craft has made more than a dozen trips to the station.