The International Space Station (ISS) has been grappling with a persistent air leak in its Russian Zvezda module for years, posing a significant safety risk to both the station's structure and the astronauts aboard. This issue has been a source of ongoing tension between NASA and Roscosmos, with the latter initially reporting the leak in 2019 and attempting various repairs. The situation escalated in June 2026 when NASA ordered its crew to shelter in place due to a risky repair plan by Roscosmos, which involved cutting away a load-bearing bracket with a saw. This prompted a reevaluation of the strategy, leading to a potential decommissioning of the affected module.
The PrK module, which connects a docking port to the Zvezda module, has been the primary focus of the leak. Despite multiple repair attempts, the air continues to escape at an increasing rate, doubling from one pound per day to over two pounds per day since 2019. This alarming trend has led NASA to classify the leak as the highest risk, indicating a critical situation. The disagreement between NASA and Roscosmos on the root cause and repair methods further complicated matters.
A turning point emerged in June 2025 when NASA detected a new pressure signal in the Russian module, suggesting that previous repair attempts were effective. However, this progress was short-lived as Russian cosmonauts noticed a slow pressure drop in the Zvezda module during cargo unloading in May 2026, indicating that the leak persisted. The situation reached a critical juncture when Roscosmos planned to use a saw to access the crack, a move NASA deemed risky and potentially damaging to the station's structure.
The tension between the two space agencies culminated in a decision by Roscosmos to decommission the PrK module. This involves permanently closing the hatch to the service module to minimize air loss and isolate the leak. While this solution addresses the immediate issue, it also presents challenges for Russian cosmonauts, who will no longer have access to the module for supplies transfer. The decommissioning plan, however, offers a glimmer of hope for ending the air leak saga, bringing a potential resolution to this long-standing problem.
