Nasa tells astronauts to return to International Space Station as air leak repair paused

By Vivian Ho • June 5, 2026 • Science

After two hours of sheltering while Russian crew attempted to fix air leak, Nasa says ‘safe haven procedures’ have been paused

Nasa order the four crew members of its SpaceX Crew-12 mission at the International Space Station and a fifth American astronaut aboard the orbital lab to shelter in the Dragon spacecraft and prepare for a possible evacuation while the Russian Roscosmos space agency prepared to take on a more extensive repair operation of some air leaks in the Russian segment of the space station. The astronauts ordered to shelter and prepare for evacuation were American astronauts Jessica Meir and Jack Hathaway, French astronaut Sophie Adenot of the European Space Agency and Russian Roscosmos cosmonaut Andrey Fedyaev of Nasa’s SpaceX Crew-12 mission. A fifth American astronaut ordered to prepare for potential evacuation, Chris Williams, had been aboard the International Space Station for 190 days, alongside Roscosmos cosmonauts Sergey Kud-Sverchkov and Sergey Mikayev. The air leaks were located in the transfer tunnel of the Zvezda Service Module. Roscosmos has been dealing with cracks and air leaks in its station compartments for more than five years, with Nasa’s office of inspector general calling them “a top safety risk”. In June, a chartered spaceflight for India, Poland and Hungary’s first astronauts in decades was postponed over leak concerns. Roscosmos told journalists that two air leaks were discovered during the pressurisation of the Zveda module’s transfer chamber, the Russian state news agency Tass reports. Specialists with the Russian segment’s main operations team were able to seal one leak site quickly with a layer of the two-component sealant “Germetal-1.” The second potential leak site is located on the conical portion of the transfer chamber. There was no threat to the safety of the crew or the ISS onboard systems, Roscosmos told Tass. After about two hours, Nasa instructed the crew to return to the space station. “Roscosmos has paused Friday’s structural repair efforts inside the Zvezda service module transfer tunnel, known as PrK, as more measurements and data is assessed,” Bethany Stevens, a spokesperson for Nasa, posted on X. Roscosmos told journalists that the two air leaks that prompted Nasa to order five astronauts aboard the International Space Station to prepare for a possible evacuation were discovered during the pressurisation of the Zveda module’s transfer chamber, the Russian state news agency Tass reports. Specialists with the Russian segment’s main operations team detected the air leaks while pressurising the transfer chamber to the ISS chamber, Roscosmos said in a statement. They were able to seal one leak site quickly with a layer of the two-component sealant “Germetal-1.” The second potential leak site is located on the conical portion of the transfer chamber. There was no threat to the safety of the crew or the ISS onboard systems, Roscosmos told Tass. After about two hours of sheltering in their spacecraft and preparing for potential evacuation, the four members of SpaceX Crew-12 and a fifth Nasa astronaut were instructed by Nasa to return to the International Space Station, a Nasa spokesperson said on Friday. “Roscosmos has paused Friday’s structural repair efforts inside the Zvezda service module transfer tunnel, known as PrK, as more measurements and data is assessed,” Bethany Stevens, a spokesperson for Nasa, posted on X. “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. We look forward to working with Roscosmos on a collaborative approach to address the leaks.” The air leaks appear to have been an issue for the International Space Station for some time: In June, a chartered spaceflight for India, Poland and Hungary’s first astronauts in decades was postponed over leak concerns. The Russian Roscosmos space agency has been dealing with cracks and air leaks in its station compartments for more than five years, with Nasa’s office of inspector general calling them “a top safety risk”. More here: Here is some live feed being taken from the International Space Station: A Nasa spokesperson said on Friday that the air leaks that prompted Nasa to order five astronauts aboard the International Space Station to prepare for a possible evacuation were located in the transfer tunnel of the Zvezda Service Module. According to Nasa, this module is about 43 feet in length and contains living quarters, life support systems, communications systems, electrical power distribution, data processing systems, flight control systems and propulsion systems. It was the first fully Russian contribution to the ISS and includes a docking port for Russian Soyuz and Progress spacecraft. The International Space Station is an orbital laboratory located about 250 miles above Earth. It is operated by five partner space agencies: the American National Aeronautics and Space administration (Nasa), the Canadian Space agency (Csa), the European Space Agency (Esa), the Japan Aerospace Exploration Agency (Jaxa) and the Russian State Space Corporation “Roscosmos”. International crews travel to the ISS to conduct scientific research in microgravity. There has been a continuous human presence aboard the space station for 25 years, according to Nasa, with the ISS celebrating this milestone in November 2025. The station is currently divived into two sections, the Russian Orbital Segment (Ros) that is managed by Roscosmos and the US Orbital Segment (USOS) that is operated by Nasa, ESA, Jaxa and CSA. A fifth American astronaut, Chris Williams, is also sheltering and preparing for potential evacuation alongside the four members of Nasa’s SpaceX Crew-12, a Nasa spokesperson said Friday. Chris Williams has been at the International Space Station for 190 days, alongside Roscosmos cosmonauts Sergey Kud-Sverchkov and Sergey Mikayev, according to a live ISS tracker. The air leaks that prompted Nasa to order its crew to prepare for a possible evacuation have “been a concern” for some time, a Nasa spokesperson said, with the Russian space program electing to proceed with more extensive repairs on Friday in response to new leaks. “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,” Bethany Stevens, a spokesperson for Nasa, posted on X. She continued: “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.” “Following new leaks, Roscosmos has elected to proceed with a more extensive repair operation on Friday, June 5.” Nasa issued the order “out of an abundance of caution”, Stevens said. The astronauts ordered by NASA to prepare for a possible evacuation on Friday are part of NASA’s SpaceX Crew-12 mission. American astronauts Jessica Meir and Jack Hathaway, French astronaut Sophie Adenot of the European Space Agency and Russian Roscosmos cosmonaut Andrey Fedyaev make up the 12th crew rotation with SpaceX for NASA’s commercial crew program. They have been at the orbiting International Space Station laboratory since February, conducting scientific investigations and technology demonstrations to help prepare humans for future exploration missions to the Moon and Mars. NASA has ordered its astronauts aboard the International Space Station to shelter in their spacecraft and prepare for potential evacuation on Friday over a worsening leak of air in the Russian portion of the orbital laboratory, Reuters reports. We’ll bring you more on this breaking story…

Source: The Guardian