According to a report in Russia’s state-run press today, the repairs to the air leak in the Russian Zvezda module on ISS have reduced the rate of air lose significantly, but have failed to eliminate it.

Long-term observations have shown that the leak in the interstitial chamber of the Zvezda module of the International Space Station, which was reported to have been fixed in June, is still ongoing, though its rate has slowed significantly, Roscosmos Executive Director of Manned Space Programs, special presidential envoy for international space cooperation Sergey Krikalyov said.

“The leak is ongoing. We continue our efforts to find and fix it, with the recent repairs having seriously reduced the rate of air leakage. For some time we even thought that we had found the last crack and sealed it, though long-term observations have shown that it (air loss – TASS) continues,” he told a press conference ahead of the launch of the Crew Dragon Endeavour spacecraft carrying the Crew-11 mission crew.

Even if Russia succeeds eventually in sealing the leak entirely, this does not solve a more fundamental problem, the existence of stress fractures in the hull of Zvezda that have caused the leaks. That module, built in the 1990s and the second oldest module on ISS, remains at serious risk of catastrophic failure due to these fractures. That the leak has not yet been sealed suggests that new cracks are steadily forming even as Russian astronauts patch older cracks.

Though they do not say so, officials at both Roscosmos, NASA, and their partners in Europe and Japan are all praying that the station can last until 2030, when they plan to retire and de-orbit it. They all know however that there is a great risk that Zvezda will not cooperate, and cause an unplanned shut down much earlier.