Space station crew shelters in Dragon over air leak

NASA ordered the crew of the International Space Station on June 5, 2026, to take up a heightened safety posture inside the docked SpaceX Dragon capsule while the Russian side worked to seal a worsening air leak in the Zvezda module. The agency said the measure was taken as a precaution, and the crew remained in the spacecraft while the work continued.

Sheltering in the capsule were Crew-12 astronauts Jessica Meir and Jack Hathaway of NASA, Sophie Adenot of the European Space Agency, and Roscosmos cosmonaut Andrei Fedyaev, along with NASA astronaut Chris Williams, who had arrived at the station aboard a Soyuz. Dragon is docked to the station’s U.S. segment and, in situations like this, serves as a zone from which the crew could undock quickly if that became necessary.

Where the air is leaking

The leak is in a transfer tunnel known by the designation PrK, which connects the station to Russia’s Zvezda service module. It is a narrow passage that provides access to an older part of the Russian segment. The problem there is not new. Russia has been tracking it since 2019, when small cracks were first found in the hull, slowly letting air escape from the station.

Over the past few years the air loss had been measurable but controlled, and Russian engineers periodically closed the hatch to the tunnel and reapplied sealant. The latest decision to shelter the crew came after the rate of air loss increased compared with earlier readings. NASA said the posture in Dragon was temporary and tied to the duration of the repair.

“Out of an abundance of caution, NASA directed all Crew-12 members and astronaut Chris Williams to take up a heightened safety posture aboard the Dragon spacecraft while the repair was under way,” the agency said.

What this means for the station

Judging the severity of a leak on an orbital station is not simple. The rate of air loss shifts with temperature and pressure, so a single reading says little without the context of several consecutive measurements. That is why decisions to shelter a crew are sometimes made before a concrete danger is confirmed, simply because the cost of an error in space is high.

Cracks in the Zvezda module have been a point of discussion between NASA and Roscosmos for years, and the two agencies do not always agree on how serious they are or how best to fix them. What can be said from the available data is that the sheltering measure was preventive and that the repair is being carried out by the Russian side. How long it will take, and whether the sealing will solve the problem for good this time, cannot be concluded from what has been published so far.

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