Five astronauts aboard the International Space Station were told by NASA to return to normal duties after spending about two hours sheltered inside a docked spacecraft during concerns over a worsening air leak in the station’s Russian segment.
Earlier on Friday, NASA instructed the four-member Crew-12 team and another U.S. astronaut to enter their docked SpaceX Crew Dragon capsule and put on spacesuits as a precaution. The move was part of NASA’s “safe-haven” protocol, used when there is a potential threat to crew safety.
The alert was triggered while Russian cosmonauts were attempting repairs in the aging Zvezda service module, where a long-running air-leak problem has persisted for years. NASA said the leak rate unexpectedly increased, prompting concern that the situation could worsen during repair work.
After further assessment by NASA and the Russian space agency Roscosmos, the shelter order was lifted and the astronauts were allowed to return to the station.
Roscosmos later reported that two leaks had been detected in the transition chamber of the Zvezda module. One leak was successfully sealed with a special compound, while preparations continue to repair the second. The agency said the station’s internal pressure remains stable and there is no immediate danger to the crew.
The incident highlights ongoing concerns about the aging ISS infrastructure. Small leaks in the Russian segment have been monitored since 2019, leading to repeated inspections and repairs. Although Friday’s event prompted a rare evacuation-ready posture, the station has never required a full emergency evacuation in its 27-year history.
