NASA Orders ISS Crew-12 to Shelter in SpaceX Crew Dragon — Worsening Zvezda Air Leak Triggers Precautionary Evacuation to Capsule

NASA directed four NASA Crew-12 astronauts — Jessica Meir, Jack Hathaway, Sophie Adenot, and Andrey Fedyaev — plus a fifth astronaut, Chris Williams, to don suits and board their docked SpaceX Crew Dragon capsule at 9:04 a.m. EDT on June 5, 2026, as a precautionary shelter-in-place measure. The air leak was located in the Zvezda service module's transfer tunnel (PrK) in the Russian segment of the International Space Station and had been worsening since Monday, increasing from approximately 0.5 kg/day to approximately 1 kg/day of air loss. SpaceX's Crew Dragon served as the designated emergency shelter and potential evacuation vehicle. Roscosmos opted to conduct pressure measurements only on June 5 rather than proceed with immediate full repairs, and NASA reversed the shelter order later in the day once it was determined the leak rate was manageable. The incident underscores Crew Dragon's critical role in ISS crew safety: as the only currently crewed U.S. vehicle certified for ISS operations following Boeing Starliner's 2025 retirement, Crew Dragon functions as the de facto ISS lifeboat. This is the latest in a series of air leaks in the Russian ISS segment that have periodically required crew precautionary actions since 2019.