There's another leak on the International Space Station, and NASA has already delayed one crew launch to the orbiting laboratory as a result.
Beyond that, the space agency is not offering much information about the unfolding situation in orbit. However, multiple sources have confirmed to Ars that the leak is a serious concern for the space agency as it deals with hardware that is approaching three decades in orbit.
To understand the current situation, it is important to review past leaks on the station, which has an aluminum structure. The station has had a slow but increasing leak since 2019. The air leaks are located in the transfer tunnel of the space station's Russian Zvezda service module, one of the oldest elements of the complex, the first elements of which were launched in 1998. The transfer tunnel, known by the Russian acronym PrK, connects the Zvezda module with a docking port where Soyuz crew and Progress resupply spacecraft attach to the station.
From time to time, Russian cosmonauts have experimented with repairs to the small cracks, but they have generally only slowed the progression of the leak, which amounts to a couple of pounds of air per day. The best solution has been to close the hatch leading to the PrK module except when spacecraft dock with the attached port.
So what’s going on?
Roscosmos recently confirmed that it completed its most recent repairs on the PrK module earlier this month, saying it had been "completely sealed." NASA has also said that repairs were recently wrapped up. After this, both Roscosmos and NASA said the leak rate inside the PrK module had halted.
This seems like good news. However, the overall air pressure in the space station at large continued to drop, according to two sources. So if the PrK module was not leaking, as it had been doing for half a decade, why was the space station still losing air pressure?