Four astronauts undock from International Space Station, with the affected crewmember in a stable condition, says space agency

Four crew members have left the International Space Station (ISS) and are heading back to Earth after a medical issue prompted their mission to be cut a month short in Nasa’s first medical evacuation.

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 on Wednesday, after five months in space.

“Our timing of this departure is unexpected,” Cardman said before the return trip, “but what was not surprising to me was how well this crew came together as a family to help each other and just take care of each other.”

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.