The four astronauts making a historic medical evacuation from the International Space Station (ISS) will be coming home in less than a week, NASA has revealed.

Space agency officials announced that Crew-11 would leave the station no earlier than 5pm ET on Wednesday, January 14, roughly one month sooner than their scheduled departure date.

The SpaceX Dragon capsule bringing the astronauts home is excepted to splash down off the coast of California around 3.40am Thursday morning on January 15.

The sudden exit was triggered by what new NASA administrator Jared Isaacman described as a 'serious medical condition' suffered by one of the astronauts which required further treatment back on Earth.

'Mission managers continue monitoring conditions in the recovery area, as undocking of the SpaceX Dragon depends on spacecraft readiness, recovery team readiness, weather, sea states, and other factors,' NASA said in a statement Friday night. 

While NASA did not reveal which astronaut experienced the emergency or what happened, officials said they were 'erring on the side of caution' and evacuating the entire Crew-11 team as soon as possible.

Crew-11 includes four astronauts: NASA's Zena Cardman and Mike Fincke, Japanese astronaut Kimiya Yui, and Russian cosmonaut Oleg Platonov.

NASA's chief medical officer Dr James Polk has said the ailing astronaut is currently in 'stable' condition, noting that their medical issue did not occur because of an accident on the station or anything related to their work in space.

Crew-11 before launching to the ISS. Pictured (L to R): Roscosmos cosmonaut Oleg Platonov, NASA astronaut Mike Fincke, JAXA astronaut Kimiya Yui, and NASA's Zena Cardman

Crew-11's SpaceX return capsule will depart the International Space Station on Wednesday, January 14

'Due to medical privacy, it is not appropriate for NASA to share more details about the crew member,' NASA added. 

'It's mostly having a medical issue in the difficult areas of microgravity,' Polk explained without going into specifics at a Thursday press conference.

Elon Musk's SpaceX, which created the Dragon capsules used to ferry NASA astronauts and cargo to the ISS, confirmed the evacuation plan on social media last night.

According to NASA, the four astronauts will close the hatch on the Dragon capsule around 3.30pm on Wednesday and begin undocking procedures at 4.45pm.

Once Crew-11 leaves the ISS, it will take approximately seven hours for the spacecraft to fly to the point above Earth where its deorbit will begin.

The deorbit, scheduled for around 2.50am Thursday morning, involves Crew-11 firing its engines briefly to reduce the capsule's speed, slowing the craft down enough for gravity to take over and pull it back toward Earth.

Without this slowdown, the Dragon capsule would just keep circling endlessly in space.

Crew-11 arrived at the ISS on August 1, 2025, and their original return date had been scheduled for late February.

NASA administrator Jared Isaacman (Left) and NASA chief medical officer Dr James Polk (Center) revealed on Thursday that Crew-11 would be returning as soon as possible 

JAXA astronaut Kimiya Yui (center) was helping NASA astronaut Zena Cardman (left) and Mike Fincke prepare for the spacewalk before it was postponed 

NASA previously planned for the four astronauts to leave after their replacements from Crew-12 arrived in a new Dragon capsule around February 15.

Isaacman said no decision had been made yet on whether Crew-12's launch will be moved up because of the medical evacuation.

Until their launch, NASA astronaut Chris Williams and Japanese astronaut Koichi Wakata, who arrived at the ISS aboard a Russian Soyuz spacecraft in November 2025, will be maintaining the station.

Until now, there had never been a crew evacuated ahead of their scheduled departure time from the ISS.

However, just 10 months ago, SpaceX and NASA carried out a historic rescue mission to retrieve astronauts Sunita Williams and Butch Wilmore, who had been stranded on the ISS for 286 days after their Boeing spacecraft Starliner malfunctioned.

A Thursday morning press conference has already been scheduled once Crew-11 returns safety to Earth.

Isaacman noted that the medical evacuation and potential change in Crew-12's launch would not impact the upcoming Artemis moon mission, currently scheduled for February 2026.

Calling the two situations 'totally separate campaigns,' the NASA chief said Artemis II was still on track to become the first manned spaceflight to orbit the moon since 1972.