The crew aboard NASA's giant orbiting laboratory is facing a troubling new setback as engineers investigate an air leak in a section of the station that has been plagued by cracks for years.
NASA confirmed to Ars Technica that the International Space Station is leaking air again from a Russian module that has suffered similar problems since 2019. The leak, detected on May 1, is allowing roughly one pound of air to escape into space each day — about the weight of a loaf of bread.
NASA said the affected module is being maintained at a lower pressure and can be periodically repressurized as needed, adding that station operations have not been impacted. However, the issue has become so serious that NASA has reportedly ranked it among the highest-risk challenges facing the station, with the possibility of a 'catastrophic failure' discussed during internal meetings.
There are currently seven people aboard the ISS, including three NASA astronauts, one European Space Agency astronaut and three Russian cosmonauts, who NASA said are coordinating on next steps. While NASA said the leak poses no immediate danger, the agency maintains emergency evacuation procedures that would allow astronauts to abandon the station aboard docked spacecraft if the situation were to deteriorate.
Emergency Protocols in Place
Those protocols include measures to isolate damaged sections of the station and, in an extreme scenario, evacuate astronauts back to Earth. The latest leak was detected on May 1 in a Russian module that has been plagued by cracks and pressure losses for years. If sensors detect a rapid loss of pressure, alarms immediately sound throughout the station and astronauts gather in a designated safe area to assess how much time remains before conditions become dangerous.
The crew then checks docked spacecraft, such as a Soyuz or Crew Dragon capsule, to ensure their emergency escape vehicles have not been affected. Astronauts would next begin isolating sections of the station by closing hatches between modules, much like sealing watertight compartments on a ship. By monitoring pressure levels in each section, crews can identify which module is leaking air.
Once the source is narrowed down, astronauts use specialized ultrasonic equipment to locate the exact crack or puncture. Temporary repairs can include emergency patches, sealants or other materials designed to slow or stop the loss of air while engineers on the ground develop a more permanent fix. In a worst-case scenario, if the leak could not be isolated or repaired before pressure dropped to unsafe levels, the crew would abandon the station and return to Earth aboard their docked spacecraft.
History of the Leak
The trouble began in September 2019, when astronauts detected a small but persistent air leak in the PrK transfer tunnel, a narrow vestibule connecting a docking port to the Russian-built Zvezda service module. Investigators eventually traced the problem to a series of microscopic cracks in the aging structure, prompting years of inspections and repair attempts.
Despite repeated efforts to seal the cracks, the situation worsened over time. By 2024, the leak rate had roughly doubled, leading NASA to elevate the issue to one of the station's most serious safety concerns and placing it among the highest risks facing the orbiting laboratory. Astronauts were advised to stay near their spacecraft when the affected Russian module was opened, allowing them to quickly evacuate if conditions deteriorated, while NASA and Roscosmos moved to keep the hatch sealed whenever possible as the rate of air loss continued to climb.
There appeared to be a breakthrough in June 2025, when NASA reported that repair work had significantly reduced the air loss and suggested the leak was finally under control. The American space agency became even more optimistic in January 2026, announcing that the affected section had reached what officials described as a 'stable configuration,' raising hopes that the years-long problem had been resolved. However, it appears that those hopes were short-lived.
Finch told Ars: 'Roscosmos allowed the pressure in the transfer tunnel to gradually decrease while monitoring the rate. The area is now being maintained at a lower pressure, with small repressurizations as needed. There are no impacts to station operations, and NASA and Roscosmos are coordinating on next steps.'
The Daily Mail has contacted NASA for comment. The ISS is scheduled to retire in 2030 and be guided into a controlled reentry over the South Pacific by a SpaceX-built deorbit vehicle. However, NASA and Congress are considering extending its lifespan to 2032 or beyond until commercial replacements are ready.
