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.
The affected crew member “was and continues to be in stable condition”, Nasa official Rob Navias said on Wednesday.
The SpaceX Dragon capsule carrying the four crew members is scheduled to splash down off the California coast at around 0840 GMT on 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.
“This was a deliberate decision to allow the right medical evaluations to happen on the ground, where the full range of diagnostic capability exists. It’s the right call, even if it’s a bit bittersweet.”
Computer modelling predicted a medical evacuation from the space station every three years, but Nasa hasn’t had one in its 65 years of human spaceflight. The Russians have not been as fortunate. In 1985, Soviet cosmonaut Vladimir Vasyutin came down with a serious infection or related illness aboard his country’s Salyut 7 space station, prompting an early return. A few other Soviet cosmonauts encountered less serious health issues that shortened their flights.
The Crew-11 quartet arrived at the ISS in early August and had been scheduled to stay onboard the space station until they were rotated out in mid-February with the arrival of the next crew.
James Polk, Nasa’s chief health and medical officer, said “lingering risk” and a “lingering question as to what that diagnosis is” led to the decision to bring back the crew earlier than originally scheduled.
American astronaut Chris Williams and Russian cosmonauts Sergey Kud-Sverchkov and Sergei Mikaev, who arrived at the station in November aboard a Russian Soyuz spacecraft, are remaining on the ISS.
Until SpaceX delivers another crew, Nasa said it would have to stand down from any routine or even emergency spacewalks, a two-person job requiring backup help from crew inside the orbiting complex.
The Russian Roscosmos space agency operates alongside Nasa on the outpost, and the two agencies take turns transporting a citizen of the other country to and from the orbiter – one of the few areas of bilateral cooperation that still endure between the United States and Russia.
Continuously inhabited since 2000, the ISS seeks to showcase multinational cooperation, bringing together Europe, Japan, the US and Russia.
The four astronauts being evacuated had been trained to handle unexpected medical situations, said Amit Kshatriya, a senior Nasa official, praising how they had dealt with the situation.
With Agence France-Presse and Associated Press