The affected area is known as the PrK transfer tunnel. NASA and Roscosmos have been monitoring the leak for years while working to understand its root cause and reduce the loss of air. Roscosmos has used both temporary and permanent sealants as part of its leak mitigation efforts.

Leak Rate Rises During Progress 95 Operations

According to NASA's latest update, Roscosmos detected a higher leak rate during cargo operations involving the Progress 95 spacecraft during the week of June 1. The leak rate increased to about two pounds per day, and engineers identified new suspected leak areas inside the PrK.

Following those findings, Roscosmos decided on Friday morning to prepare for a more extensive inspection and structural repair effort. The revised plan included cutting a bracket to improve access to an area that may have been contributing to the leak. NASA noted that this method could have increased the risk to the surrounding structure.

Astronauts Enter Safe Haven as Precaution

Because of the potential structural risk, NASA directed the four SpaceX Crew-12 members and NASA astronaut Chris Williams to take a heightened safety posture known as a safe haven. Williams traveled to the station aboard the Soyuz MS-28 spacecraft.

As a precaution, the astronauts sheltered inside the SpaceX Dragon spacecraft while the repair procedure was being evaluated.

Roscosmos Pauses Repair Work for More Data

Later Friday morning, Roscosmos chose not to proceed with the structural repair work. Instead, teams paused the operation to gather more measurements and review additional data.

The follow-up work included inspecting suspected areas of interest and reviewing places where sealant had already been applied. NASA strongly supported the decision to collect more information before moving ahead.

After Roscosmos paused the repair effort, Crew-12 and Williams ended their safe haven activities and returned to normal operations aboard the orbiting laboratory.

NASA said it will continue working with Roscosmos and the space station's other international partners to assess the situation and ensure the leak issue is resolved.