Four crew members have left the International Space Station (ISS) to return to Earth a month early, marking NASA’s first-ever space medical evacuation. The agency cut the mission short after a medical issue occurred with one of the astronauts.On Wednesday, American astronauts Mike Fincke and Zena Cardman, Russian cosmonaut Oleg Platonov, and Japanese astronaut Kimiya Yui undocked their SpaceX Dragon capsule. They target a Thursday splashdown off the California coast. The quartet arrived at the station in early August and originally intended to stay until mid-February.Officials from NASA refused to name the affected crew member but emphasized the return is not an emergency. Agency official Rob Navias stated the astronaut “was and continues to be in stable condition.”The decision to evacuate was sudden, with Cardman commenting on the “unexpected” timing but commending the team for uniting “as a family.” Fincke described the move as the “right call” despite being “bittersweet,” as it allows for a proper medical evaluation on the ground.According to NASA’s chief health officer, James Polk, the evacuation was primarily driven by “lingering risk” and the need for better diagnostic capabilities.Although computer models had predicted a medical evacuation once every three years, this is the first in NASA’s 65-year history of human spaceflight. The only historical precedent is the Soviet Union’s evacuation of a cosmonaut in 1985 due to a severe infection.Three crew members—American Chris Williams and Russians Sergey Kud-Sverchkov and Sergei Mikaev—are currently on the International Space Station (ISS).Until SpaceX delivers additional support, NASA will suspend all routine and emergency spacewalks, as these tasks require backup assistance from inside the station. This situation underscores the ongoing collaboration between NASA and Roscosmos, even as they navigate this unexpected disruption to their schedule.