NASA orders station astronauts to shelter over Zvezda air leak concerns

NASA instructed astronauts aboard the International Space Station to seek immediate shelter Friday amid concerns over a persistent air leak in the Russian-controlled Zvezda service module, directing four crew members to seal themselves inside a docked Crew Dragon spacecraft while wearing full spacesuits.

Safety posture

Bethany Stevens, a NASA spokeswoman, confirmed the precautionary measure on X, stating the agency directed its SpaceX Crew-12 contingent — including NASA astronaut Chris Williams — to assume an elevated safety posture inside the Dragon capsule during repair operations. Four of the seven astronauts currently stationed aboard the orbiting laboratory relocated to the docked spacecraft at the direction of NASA mission control, according to the agency's statement.

Module integrity

The air leak originates from the PrK transfer tunnel in the Zvezda module, a section that has suffered from cracks for an extended period despite mitigation efforts by Roscosmos, Russia's space agency. "The Zvezda service module transfer tunnel, known as PrK, has suffered from cracks and leaks for some time, and has been mitigated by Roscosmos as much as possible to date," Stevens noted, adding that both agencies have been working to determine the root cause of the fissures.

Roscosmos is scheduled to carry out repair work on Friday while NASA continues monitoring the situation closely. "We continue to work with our Russian counterparts, along with the rest of the international community that supports the space station, to arrive at a more permanent resolution," Stevens said. The Zvezda module serves as a primary service and living quarters for the Russian segment of the station, which currently hosts seven crew members total.