What you should know about leaks on the International Space Station

A new report from NASA details that persistent air leaks at the International Space Station (ISS) pose “a major safety risk.”

The report released Sept. 26 by NASA’s Office of Inspector General and signed by Deputy Inspector General George A. Scott said the leak was in a tunnel connecting the Russian segment of the ISS to a docking port. According to the report, NASA and the Russian space agency Roscosmos continue to “work together to address structural issues with the Russian Service Module Transfer Tunnel.”

“According to NASA, Roscosmos is confident that they will be able to monitor and close the hatch to the service module before the leak rate reaches an unsustainable level,” the report said. “However, NASA and Roscosmos have not reached agreement on the point at which the leak rate is unsustainable.”

This leak, the root cause of which remains unknown, has already been discussed in the public forum, with Russia acknowledging the issue back in February. However, they said it did not pose a safety risk to the crew. Still, the newly released report states that NASA detected an “increase in the leak rate to its highest level ever” in April 2024.

In May and June, representatives from the ISS program and Roscosmos met to discuss their increasing concerns about the increased leak rate. “As of August 2024, the leak risk in the service module transfer tunnel is assessed at 5 x 5,” the report said. NASA’s risk scorecard is based on both “risk probability,” which is the likelihood that a potential risk will occur, and “risk impact,” which is the potential harm that could occur if a problem occurs. Five is considered “hardest” on the five-point scale.

If the leaks continue, NASA and Roscosmos could be forced to permanently close the hatch to the affected tunnel, which would prevent astronauts from using any of the four docking ports for the Russian segment. Currently, the report says they are constantly monitoring the leaks and temporarily closing the hatch when it is not needed.

The ISS is only scheduled to operate with NASA until 2030. At this point, they plan to work with SpaceX and exit the station in a controlled manner. In 2023, Russia committed to remaining on board until 2028 and plans to build the core of a new space station by 2030.

NASA’s September inspector general report includes some recommendations for NASA’s crew, including re-examining orbiting debris tracking instruments to “ensure the safety of the crew” and documenting “contingency plans” in the event of an emergency and in the event that the air leaks become worse due to damage.