Air is leaking from the International Space Station. The U.S. and Russia can’t agree why

The International Space Station (ISS) has an air leakage problem — and tensions between the U.S. and Russia appear to be getting in the way of a solution.

The aging ISS is leaking more than 3 pounds of air a day in a docking port of the station, called a PrK module, that belongs to the Russians. The leakage has been happening since 2019 and NASA is worried it could have serious consequences, Ars Technica reported.

Repairs have helped but not solved the problem, the source of which the Russians and Americans can’t agree on. Officials from the two countries “don’t have a common understanding of what the likely root cause is, or the severity of the consequences of these leaks,” said Bob Cabana, a former NASA astronaut who runs NASA’s International Space Station Advisory Committee, according to Ars Technica.

Russians believe the cracks are caused by “high cyclic fatigue caused by micro-vibrations,” Cabana said earlier this month, and NASA thinks the issue is “multi-causal,” caused by “pressure and mechanical stress, residual stress, material properties, and environmental exposures.”

They also can’t seem to agree on how catastrophic the leaks might be.

While the Russian team continues to search for and seal the leaks, it does not believe catastrophic disintegration of the PrK is realistic,” Cabana said, according to Space News. Meanwhile, he said that NASA has “expressed concerns about the structural integrity of the PrK and the possibility of a catastrophic failure.”

The two parties are locked in a stalemate. Russians think it is safe to continue operations of the PrK module, but can’t prove it. And Americans think it is unsafe to continue, but can’t prove that either.

“This is an engineering problem, and good engineers should be able to agree on it,” Cabana added.