What to Know About the Leak at the International Space Station: ‘A Top Safety Risk’

A new report from NASA details how ongoing air leaks at the International Space Station (ISS) are “a top safety risk.”

The report, published from NASA’s Office of Inspector General on Sept. 26 and signed by Deputy Inspector General George A. Scott, states the leak is in a tunnel connecting the ISS’ Russian segment to a docking port. Per the report, NASA and Russia’s space agency Roscosmos are continuing to “work together to address structural issues with the Russian Service Module Transfer Tunnel."

“According to NASA, Roscosmos is confident they will be able to monitor and close the hatch to the Service Module prior to the leak rate reaching an untenable level," the report reads. “However, NASA and Roscosmos have not reached an agreement on the point at which the leak rate is untenable.”

This leak—the root cause of which remains unknown—has been discussed in the public forum previously, with Russia acknowledging the issue back in February. However, they said it posed no safety hazard to the crew. Yet, the newly-released report states that in April 2024, NASA identified an “increase in the leak rate to its highest level to date.”

In May and June, ISS Program and Roscosmos officials met to discuss their heightened concerns over the increased leak rate. "As of August 2024, the Service Module Transfer Tunnel leak risk is scored as a 5 by 5," the report states. NASA’s risk scorecard is based on both “risk likelihood,” meaning the probability of a potential risk happening, and “risk impact,” meaning the potential damage that could occur if a problem does arise. Five is considered to be "the most severe" on the five-point scale.

If the leaks continue, NASA and Roscosmos may be forced to permanently close the hatch to the affected tunnel, which would cut astronauts off from using one of the four docking ports for the Russian segment. Currently, the report states that they are monitoring the leaks constantly and temporarily sealing the hatch when it is not needed.

The ISS is only planned to be in operations with NASA through 2030, at which point they are planning to partner with SpaceX and deorbit the station in a controlled manner. In 2023, Russia committed to stay aboard until 2028, and are planning to create the core of a new space station by 2030.

NASA’s September Inspector General report offers some recommendations to NASA’s crew, including reexamining orbital debris tracking tools to “ensure crew safety,” and documenting “contingency plans” in case of emergency and if the air leaks do get worse from damage.