Nasa is considering an early return of some crew aboard the International Space Station (ISS) because of a medical issue involving one member of a four-strong team.
The unnamed crew member is described as stable, but the incident has already led to the last-minute cancellation of a spacewalk.
Mission managers are now weighing whether the safest option is to bring the entire Crew 11 team back to Earth months ahead of schedule. Three members of another crew would remain on board.
"Safely conducting our missions is our highest priority, and we are actively evaluating all options, including the possibility of an earlier end to Crew 11's mission," said a Nasa spokeswoman.
On Wednesday Nasa abruptly cancelled a spacewalk due for Thursday when two astronauts were set to step outside the ISS and announced that it was because one of the crew was unwell.
