ISS Leak Forces Astronauts to Shelter in SpaceX Capsule

NASA ordered five astronauts aboard the International Space Station (ISS) to take shelter in a docked SpaceX Crew Dragon spacecraft on Friday after Russian cosmonauts discovered new air leaks in the aging Zvezda service module. The precautionary measure lasted approximately two hours before the crew was cleared to return to normal operations.

The incident unfolded Friday morning when Russian cosmonauts detected two air leaks while pressurizing the Zvezda module’s transfer chamber, known as PrK. According to AP News, the decision to move the crew was made “out of an abundance of caution,” NASA spokesperson Bethany Stevens said via X.

Shelter and Response

The five astronauts who sheltered in the SpaceX Crew Dragon included NASA Crew-12 members Commander Jessica Meir, Pilot Jack Hathaway, European Space Agency mission specialist Sophie Adenot, and Roscosmos cosmonaut Andrey Fedyaev, along with NASA astronaut Chris Williams, who has been aboard the ISS for 190 days. In total, 10 people were aboard the station at the time.

Roscosmos cosmonauts quickly sealed one leak with a two-component sealant called “Germetal-1,” TechCrunch reported. A second potential leak site was identified on the conical portion of the transfer chamber. However, Roscosmos paused the structural repair efforts to assess more measurements and data, prompting NASA to end the safe haven procedures.

“Given this development, NASA has instructed the crew members inside the Dragon spacecraft to end the safe haven procedures and return to planned operations aboard the International Space Station,” Stevens wrote in a follow-up post. “We look forward to working with Roscosmos on a collaborative approach to address the leaks.”

A Persistent Problem

The Zvezda service module, launched in July 2000 as the first fully Russian contribution to the ISS, has suffered from cracks and air leaks since at least September 2019. According to PBS NewsHour, the leak rate had been monitored over recent months but significantly worsened earlier this week, increasing from a loss of approximately one pound of air per day to two pounds per day.

NASA’s Office of Inspector General has called the Zvezda module cracks “a top safety risk.” The Guardian noted that the space agencies have been working to determine the root cause of the cracks, with Roscosmos managing the issue through operational mitigation measures and periodic partial-repair efforts.

Roscosmos stated via Russian state news agency Tass that “there was no threat to the safety of the crew or the ISS onboard systems.”

Broader Implications for the ISS

The incident comes at a critical juncture for the International Space Station, which has maintained a continuous human presence for 25 years. Under the leadership of new NASA Administrator Jared Isaacman, the agency is pushing to replace the aging ISS with commercially produced modules later this decade.

The ISS remains one of the few areas of sustained US-Russia cooperation despite geopolitical tensions on Earth. The station is divided into the Russian Orbital Segment (ROS) and US Orbital Segment (USOS), operated by five partner agencies: NASA, Roscosmos, ESA, JAXA, and CSA.

What’s Next

While the crew has returned to normal operations, the incident raises urgent questions about the long-term viability of the Zvezda module. With the leak rate accelerating and no permanent solution in sight, the episode may accelerate plans to transition to commercial space stations. For now, the partnership between NASA and Roscosmos continues, with both agencies expressing a commitment to finding a collaborative solution to the persistent structural issues.

The SpaceX Crew-12 mission, which launched February 13, 2026, continues its long-duration mission aboard the ISS as scheduled.