Astronauts told to shelter on spacecraft after air leaks are found on ISS

Astronauts aboard the International Space Station have been instructed to shelter as Russian cosmonauts carry out urgent repairs to address air leaks in the Zvezda service module’s transfer tunnel.

Five of the seven cosmonauts in the Russian segment have relocated to the docked SpaceX Crew Dragon “Freedom” spacecraft as a precautionary measure. The remaining two crew members are conducting repair operations. According to Russian news agency Interfax, one of the two identified leaks has been successfully sealed.

The second leak, located on the conical portion of the transfer chamber, does not pose an immediate threat to the crew, according to Roscosmos, the Russian space agency. Officials told state-owned Tass that the leaks were discovered during pressurisation of the Zvezda module’s transfer chamber. Cracks in the spacecraft have been present for years but were previously managed with temporary patches. Russian space officials noted a fresh pressure drop last month, prompting the more intensive repair effort now underway.

NASA spokesperson Bethany Stevens provided details on the situation. “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. The cracks have always been a concern that NASA watches very closely,” she said. “NASA and Roscosmos have been working to determine the root cause of the cracks, and Roscosmos manages the issue through operational mitigation measures and periodic partial-repair efforts.”

Stevens added that following the detection of new leaks, Roscosmos elected to proceed with a more extensive repair operation on Friday, June 5.

“Out of an abundance of caution, NASA has directed all four of the agency’s SpaceX Crew-12 members and NASA astronaut Chris Williams to assume an elevated safety posture in the Dragon spacecraft while the repair is underway. 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.”