The ISS has been leaking air for 5 years, and engineers still don’t know why

“The station is not young,” said Michael Barratt, a NASA astronaut who returned from the space station last month. “It’s been up there for quite a while, and you expect some wear and tear, and we’re seeing that.”

“The Russians believe that continued operations are safe, but they can’t prove to our satisfaction that they are,” said Cabana, who was the senior civil servant at NASA until his retirement in 2023. “And the US believes that it’s not safe, but we can’t prove that to the Russian satisfaction that that’s the case.

“So 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. “And NASA has expressed concerns about the structural integrity of the PrK and the possibility of a catastrophic failure.”

Closing the PrK hatch permanently would eliminate the use of one of the space station’s four Russian docking ports.

NASA has chartered a team of independent experts to assess the cracks and leaks and help determine the root cause, Cabana said. “This is an engineering problem, and good engineers should be able to agree on it.”

As a precaution, Barratt said space station crews are also closing the hatch separating the US and Russian sections of the space station when cosmonauts are working in the PrK.

“The way it’s affected us, mostly, is as they go in and open that to unload a cargo vehicle that’s docked to it, they’ve also taken time to inspect and try to repair when they can,” Barratt said. “We’ve taken a very conservative approach to closing the hatch between the US side and the Russian side for those time periods.

“It’s not a comfortable thing, but it is the best agreement between all the smart people on both sides, and it’s something that we as a crew live with and adapt.”