Astronauts returning to Earth in first medical evacuation from space station

Four crew members departed the International Space Station on Wednesday after a medical issue prompted their mission to be cut a month short – a first for the orbiting laboratory.

A video feed from Nasa showed American astronauts Mike Fincke and Zena Cardman, Russian cosmonaut Oleg Platonov and Japanese astronaut Kimiya Yui undocking from the ISS at 2220 GMT, after five months in space.

The US space agency has declined to disclose which crew member has the health problem or give details about the issue, but it has stressed the return is not an emergency situation.

The affected crew member “was and continues to be in stable condition,” Nasa official Rob Navias said Wednesday.

The SpaceX Dragon capsule carrying the four crew members is scheduled to splash down off the California coast overnight at around 0840 GMT (4.40pm Hong Kong time) Thursday.

“First and foremost, we are all OK. Everyone on board is stable, safe, and well cared for,” Fincke, the pilot of SpaceX Crew-11, said in a recent social media post.