Four astronauts from the International Space Station have returned to Earth a month earlier than planned after one developed a serious medical condition onboard the orbiting outpost.
Nasa confirmed that the SpaceX Dragon spacecraft carrying the US astronauts Zena Cardman and Mike Fincke, the Japanese astronaut Kimiya Yui and the Russian cosmonaut Oleg Platonov splashed down off the coast of San Diego at 12.41am local time (8.41am UK time).
The space agency has not identified the sick crew member for privacy reasons but said they were in a stable condition. It is the first time Nasa has cut short a mission to the ISS owing to a health problem.
Cardman said before the return trip: “Our timing of this departure is unexpected. 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.”
Soon after splashdown, teams on the recovery ship and two fast boats worked to secure the SpaceX Dragon and hoist it on to the deck so the crew could be brought onboard. Nasa plans to take all four to a nearby hospital for checks.
At a post-splashdown press briefing, the head of Nasa, Jared Isaacman, said: “The crew member of concern is doing fine. While this was the first time we had to return crew slightly ahead of schedule, Nasa was ready. This is exactly why we train and this is Nasa at its finest.
“Spaceflight will always carry some degree of uncertainty, that is the nature of exploration. Fundamentally, it’s why we are in space, to learn. It’s why Nasa prepares for the unexpected, so we are ready to respond decisively and safely.”
After an overnight stay in hospital, the crew are expected return to Nasa’s Johnson Space Center in Houston on Friday where they will be reunited with their families and start the standard post-flight reconditioning and evaluations.
The Crew Dragon capsule, named Endeavour, parachuted into calm waters in the Pacific Ocean after a 10-hour-plus descent from the space station. In a call to SpaceX flight control on splashdown, Cardman said: “It’s good to be home.”
The crew started their mission onboard the space station last August and spent 167 days in orbit. On 8 January, Isaacman announced they would be brought home early because one of the astronauts faced a “serious medical condition” that required treatment on the ground.
Nasa said the medical issue did not involve “an injury that occurred in the pursuit of operations”. In an emergency, the space agency can bring crews home in hours, but the astronauts were given a few days to train Chris Williams, the only Nasa astronaut remaining on the station, on the operations he would take over.
The agency cancelled a planned spacewalk last week by Cardman and Fincke, the station’s commander, during which they were to have installed new hardware outside the station. The spacewalk was not time critical and will be rolled over to the next mission, said Joel Montalbano, a Nasa official.
Space agency modelling predicts that a medical evacuation from the ISS will be needed every three years, but Nasa has not done one in 65 years of spaceflight. There have been other evacuations, however: in 1985, the Soviet cosmonaut Vladimir Vasyutin was forced to return early after developing a serious illness onboard the Salyut 7 space station.
Isaacman said there may be a case for having trained physicians on future missions to Mars, when the human body is more likely to break down than the technology supporting it, but he did not think it would have changed decision making this time.
“I think when we go through the debrief on this we’re going to learn a lot about the things we got right and did it very well and make sure we apply that in other applications going forward,” he said.
Nasa’s Williams and the Russian cosmonauts Sergey Kud-Sverchkov and Sergei Mikaev, who arrived at the space station in November on a Russian Soyuz spacecraft, are still on the ISS.
The reduced number of crew at the station means Nasa astronauts will stand down from any routine or even emergency spacewalks, which take two people to perform with crucial support from the crew inside.
The space station is operated as a partnership between Nasa and the Russian space agency Roscosmos, which take turns transporting crew to the station and back. It is one of the few areas where cooperation remains between the two countries.
