ISS crew ordered into escape craft over worsening air leak

Five astronauts aboard the International Space Station were ordered into their docked spacecraft and told to don spacesuits on Friday after new leaks emerged in a cracked section of the station's Russian-built Zvezda service module, triggering one of NASA's rarest emergency protocols before the situation was stood down approximately two hours later.

Nasa's mission control directed all four members of its SpaceX Crew-12 team and astronaut Chris Williams to take what the agency called an "elevated safety posture" inside the docked Dragon spacecraft while Roscosmos engineers attempted a more extensive repair operation on the Zvezda module's transfer tunnel, known as the PrK section.

NASA spokesperson Bethany Stevens confirmed the decision on X, describing the cracks in the Zvezda tunnel as a long-standing concern the agency has "always watched very closely".

New leaks prompted Roscosmos to move beyond previous mitigation measures and attempt a more permanent fix, and NASA chose to clear its crew from the affected area as a precaution while that work proceeded.

The Russians decided to stop the structural work within the PrK module while gathering more measurements for analysis. As NASA determined that the repair work is now not an emergency, the agency informed the crew that the "safe haven mode is no longer required" so that it could get back to normal.

In his follow-up statement, Stevens stated that NASA hopes to work with Roscosmos "on a collaborative approach to address the leaks".

There have been issues related to the structure of the Zvezda service module for NASA and Roscosmos in the past few years. 

These cracks and the resulting leaks have been resolved by both partial repairs and workarounds in the past, but what happened on Friday was the first time in the deteriorating state of the structure became a cause of evacuation of the NASA astronauts on board.

According to the statement from Roscosmos, the situation does not present any threat to the astronauts and onboard systems, as the pressure in the station remains stable. Currently, seven astronauts are onboard the station that is orbiting 250 miles away from the earth's surface.