ISS crew – Astronauts on the International Space Station temporarily took shelter and prepared for a possible evacuation after worsening air leaks linked to microscopic cracks in the PrK transfer tunnel of the Russian-built Zvezda service module. NASA ordered the crew in
For a few tense hours on the International Space Station, “normal” stopped feeling normal.
Astronauts briefly took shelter and prepared for a potential evacuation after air leaks worsened from a Russian-built module. the NASA spokesperson said today. The leaks were tied to microscopic cracks in a transfer tunnel called the PrK—an aft-end vestibule on the Zvezda Service Module that leads to a docking port for cargo spacecraft.
Zvezda was the first fully Russian contribution to the ISS, installed by Roscosmos in July 2000. Engineers first noticed the leaks in 2019. and despite multiple efforts over the years to seal them and identify their cause. the problem has persisted. As the leaks continued, the station began losing on the order of a pound of air per day.
Following new leaks. Roscosmos elected to proceed with a more extensive repair operation on Friday. June 5. according to NASA’s Bethany Stevens. In a post on the social media platform X. Stevens said. “Following new leaks. Roscosmos has elected to proceed with a more extensive repair operation on Friday. June 5. ” and added that. “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 [SpaceX] Dragon spacecraft while the repair is underway.”.
Alongside Chris Williams. at least three Crew-12 astronauts sought refuge in the docked Crew Dragon: NASA’s Jessica Meir and Jack Hathaway and the European Space Agency’s Sophie Adenot. Crew-12 also includes Roscosmos’s Andrey Fedyaev, but it was unclear whether he took shelter alongside his crewmates as directed. Fedyaev’s Russian colleagues, Sergei Kud-Sverchkov and Sergey Mikaev, remained outside of the Dragon to address the situation.
Once the astronauts entered the Dragon, NASA’s Mission Control Center at the space agency’s Johnson Space Center radioed a directive for them to exit the “safe haven configuration.” The message noted that “our Russian colleagues have elected to perform measurements only today.”
Stevens later clarified her earlier remarks in a follow-up statement on X. Roscosmos. she said. had paused Friday’s structural repair efforts inside the Zvezda service module transfer tunnel known as the PrK as more measurements and data is assessed. Stevens added, “We look forward to working with Roscosmos on a collaborative approach to address the leaks.”.
In a Russian statement released later in the day, Roscosmos officials wrote that, “The situation poses no threat to the crew’s safety or onboard systems; pressure aboard the ISS remains stable and is being maintained at the nominal level,” according to a machine translation.
Jonathan McDowell. an astrophysicist and space-situational awareness consultant. said the astronauts were probably not in imminent danger despite the shelter order—because onboard air supplies could easily make up for the ongoing losses from the leaks. Even so, he warned that the situation “is potentially extremely serious.”.
“The worry is that a small crack could suddenly get catastrophically bigger,” McDowell said. “That’s unlikely but not impossible, and that would risk loss of the station and crew.”
The episode also landed against a broader backdrop of concern for the aging ISS. The station has been in orbit for more than a quarter-century and is well beyond its intended design life. The leaking PrK has become one of the most significant issues on the station. with NASA officially elevating the problem to its highest category of concern in internal safety evaluations.
NASA says protocols are already in place to manage the leaks. The hatch leading from Zvezda to the PrK remains closed unless access to Zvezda is needed. When that hatch is opened, a corresponding hatch capping the U.S. sections of the ISS is closed to limit any catastrophic decompression to Russia’s segment.
NASA has announced plans to retire the ISS by the end of 2030, with deorbiting planned to occur shortly thereafter, though other efforts to extend the station’s life continue.
Editor’s Note (6/5/26): This is a breaking news story and will be updated.
Additional reporting by Meghan Bartels.
International Space Station ISS Zvezda module air leaks PrK transfer tunnel Roscosmos NASA SpaceX Crew Dragon Crew-12 Chris Williams Jessica Meir Jack Hathaway Sophie Adenot Andrey Fedyaev