A Russian module called Zvezda has been venting the space station's air through cracks since 2019 — losing nearly 2 kilograms a day

The Zvezda service module, the Russian segment that has anchored the back end of the International Space Station since July 2000, has been quietly leaking air into space for nearly seven years. The cracks are in a narrow vestibule called the PrK tunnel, which connects Zvezda to an aft docking port where Russian Progress cargo ships arrive. Roscosmos first reported the leak in September 2019, and the station has been losing breathable atmosphere ever since. More

(Source: Space Daily - Jun 28)