NASA has released a new update on the ongoing air leak issue within the International Space Station’s Russian Zvezda Service Module. In this issue, cracks in transport tunnels have been causing small air leaks since 2019.
The affected area is known as the PrK transport tunnel. NASA and Roscosmos have been monitoring the leak for years while working to uncover its root cause and reduce air loss. Roscosmos has used both temporary and permanent sealants as part of its leak mitigation efforts.
95 Leak rate increases while operation is in progress
According to NASA’s latest update, Roscosmos detected a higher leakage volume during a cargo shipment by the Progress 95 spacecraft during the week of June 1st. The amount of leakage increased to approximately 2 pounds per day, and engineers identified new areas of suspected leakage within PrK.
Following these discoveries, Roscosmos decided on Friday morning to prepare for a more extensive inspection and structural repair work. The revised plan included cutting the brackets to improve access to the area that may be causing the leak. NASA noted that this method could increase the risk to surrounding structures.
Astronaut enters safe haven as precautionary measure
Because of the potential structural risks, NASA directed the four members of SpaceX Crew 12 and NASA astronaut Chris Williams to assume an advanced safety position known as a safe haven. Williams flew to the station aboard a Soyuz MS-28 spacecraft.
As a precaution, the astronauts took shelter inside the SpaceX Dragon spacecraft while repair procedures were evaluated.
Roscosmos suspends repair work to add data
Late on Friday morning, Roscosmos chose not to proceed with structural repair work. Instead, the team paused their work to collect more measurements and review additional data.
Follow-up work will include inspecting the suspected areas and surveying areas where sealant has already been applied. NASA strongly supported the decision to gather more information before proceeding.
After Roscosmos temporarily suspended repair operations, Crew-12 and Williams ceased operations at the safe haven and returned to normal operations at the orbiting laboratory.
NASA said it will continue to work with Roscosmos and the space station’s other international partners to assess the situation and ensure the leak issue is resolved.

