ISS leak updates: Roscosmos says first leak has been fixed, NASA says repair efforts have been paused

NASA has said that repair efforts aboard the ISS have been paused. Bethany Stevens added that the astronauts who were sheltering wearing space suits had been told to come out.

Update: Roscosmos has said that the first leak spot has been sealed. Interfax reported that they have now moved onto the second leak spot.

NASA has asked astronauts on the International Space Station to take shelter as a leak worsens and prepare for potential evacuation. There has been an ongoing, persistent air leak, which has turned more serious now. NASA said the leak was taking place on the Russian segment of the station, and a cosmonaut is working to fix it. The leak is located in the PrK module, a small Russian transfer tunnel connected to the Zvezda service module. It connects the main part of the station to a docking port used by Russian Progress cargo spacecraft. This leak has reportedly persisted for over five years, and the apparent source is a series of microscopic structural cracks in the hull and welded joints.

NASA spokesperson Bethany Stevens said in an X post, "The Zvezda service module transfer tunnel, known as PrK, has suffered from cracks and leaks for some time, and has been mitigated by Roscosmos as much as possible to date." She added, "The cracks have always been a concern that NASA watches very closely. NASA and Roscosmos have been working to determine the root cause of the cracks, and Roscosmos manages the issue through operational mitigation measures and periodic partial-repair efforts."

Bethany further said that the new leaks have led to Russian cosmonauts carrying out "a more extensive repair operation on Friday, June 5." She added, "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 Dragon spacecraft while the repair is underway."

If the astronauts are evacuated, it will be the second one this year. In January, veteran NASA astronaut Mike Fincke fell sick, leading to first-ever medical evacuation from the ISS.

What is the leak on International Space Station?

NASA and Roscosmos have always had a disagreement over the root cause of the leak on the ISS. The Russian space agency believes the cracks are caused by structural fatigue from high micro-vibrations, probably from cargo ships docking or thruster burns. Meanwhile, NASA suspects a mix of environmental exposure, mechanical stress, and original material properties.