HOUSTON — NASA and Roscosmos reported progress in addressing an ongoing air leak in a Russian module of the International Space Station, though structural repair work was paused for further assessment, officials said on June 5, 2026.
The leak is located in the PrK transfer tunnel of the Zvezda service module, which has experienced cracks since 2019, resulting in small atmosphere leaks that have required ongoing monitoring and mitigation efforts by Roscosmos.
During cargo operations with the Progress 95 spacecraft in the week of June 1, Roscosmos detected an increase in the leak rate to about two pounds per day and identified new suspected leak areas, according to a NASA statement.
Roscosmos then initiated preparations for a more extensive inspection and structural repair effort on Friday morning, June 5. The approach included cutting a bracket to access a possible leak source, a method that raised concerns about potential elevated risk to the structure.
In response, NASA directed the four members of SpaceX Crew-12 and NASA astronaut Chris Williams to take a heightened safety posture, known as a safe haven, inside the SpaceX Dragon spacecraft as a precaution.
"Following new leaks, Roscosmos has elected to proceed with a more extensive repair operation on Friday, June 5," NASA spokeswoman Bethany Stevens said, according to reports.
Later that morning, Roscosmos paused the structural repair work to conduct additional measurements and data assessments, including inspections of suspected areas and previously applied sealants. NASA supported the decision to pause.
As a result, the crew ended the safe haven procedures and returned to normal operations aboard the station.
The incident highlights the collaborative nature of ISS operations between NASA, Roscosmos and international partners. The Zvezda module, launched in 2000, serves critical functions including crew quarters, life support systems and propulsion for the station, which has been continuously occupied since November 2000.
Roscosmos has previously applied temporary and permanent sealants to mitigate the leaks. Details on the outcome of further assessments remain unclear as of June 9.
The station continues normal operations with a full crew complement. No injuries or major disruptions were reported.
NASA and Roscosmos have worked together to identify the root cause of the cracks while implementing mitigation measures. The ISS is expected to operate through at least 2030 as part of the transition to future commercial platforms.
Officials continue to monitor the situation closely.
