NASA spokesperson Bethany Stevens disclosed early on June 6 Beijing time that a new leak point was found in the PrK transition channel of the Zvezda service module, which is under Russian management on the International Space Station. Russia subsequently launched a larger-scale repair operation on June 5. As a precaution, NASA ordered the four members of the SpaceX Crew-12 mission and astronaut Chris Williams to stand by inside the Dragon spacecraft; the two Russian cosmonauts used the docked Soyuz MS-28 spacecraft as a backup escape route. Roscosmos reported a total of two leak points, one of which was quickly sealed using Germetal-1 two-component sealant. About two hours later, Russia paused repairs to evaluate more measurement data, and NASA then lifted the contingency procedure.
The incident underscores a persistent leak problem that has been ongoing for years: the International Space Station first reported an air leak rate above standard in 2019, and the issue has continued without a permanent fix ever since. The latest situation shows the leak rate in the affected module has doubled compared to earlier readings. The conflict also lies here — according to a senior anonymous NASA official, the Russian cosmonauts used a saw to cut through the module wall to reach the leak point during repairs, a practice NASA disagreed with, triggering the shelter-in-place procedure. NASA plans to operate the station through 2030, by which time commercial space stations would take over, but Russia has yet to commit to continuing responsibility for its modules beyond 2028. This week NASA also withdrew a proposal made in March for a government-funded transitional core module, reverting to a private-sector-led approach.