NASA instructed crew members aboard the International Space Station to end safe haven procedures and return to planned operations on June 5, 2026, after Roscosmos paused structural repair work inside the Zvezda service module transfer tunnel, known as PrK, while additional measurements and data are assessed.
NASA instructed astronauts aboard the International Space Station to move into a docked SpaceX Dragon spacecraft on June 5, as Roscosmos began more extensive repair work on a long-running air leak in the Russian Zvezda service module transfer tunnel, known as PrK.
The precautionary move followed new leaks in the tunnel, where cracks and air-loss issues have been monitored for years. NASA spokesperson Bethany Stevens said Roscosmos has managed the problem through operational mitigation and periodic partial repairs, while NASA and Roscosmos continue working to determine the root cause of the cracks.
NASA directed all four SpaceX Crew-12 members and NASA astronaut Chris Williams to assume an “elevated safety posture” in Dragon while the repair work was underway. Reuters, citing a senior NASA official, reported that the leak rate had increased from about 1 pound of air per day to roughly 2 pounds per day.
No evacuation order was issued, and there was no confirmed emergency undocking, crew injury, or loss of ISS integrity during the precautionary procedure.
Later on June 5, Roscosmos paused the structural repair effort inside PrK while additional measurements and engineering data were assessed. NASA then instructed the crew members inside Dragon to end safe haven procedures and return to planned operations aboard the station.
The agency said it continues to work with Roscosmos and the wider international space station partnership toward a more permanent resolution. The cause of the cracks remains unresolved, and the latest repair pause leaves the long-running leak issue under continued technical review.