Launched in 2000, the Zvezda Service Module provides living quarters and performs some life-support system functions. (credit: NASA)

NASA and the Russian space agency, Roscosmos, still have not solved a long-running and worsening problem with leaks on the International Space Station.

The microscopic structural cracks are located inside the small PrK module on the Russian segment of the space station, which lies between a Progress spacecraft airlock and the Zvezda module. After the leak rate doubled early this year during a two-week period, the Russians experimented with keeping the hatch leading to the PrK module closed intermittently and performed other investigations. But none of these measures taken during the spring worked.

"Following leak troubleshooting activities in April of 2024, Roscosmos has elected to keep the hatch between Zvezda and Progress closed when it is not needed for cargo operations," a NASA spokesperson told Ars. "Roscosmos continues to limit operations in the area and, when required for use, implements measures to minimize the risk to the International Space Station."