NASA lifts ISS shelter order after air leak partially contained

NASA reversed a shelter-in-place order for five astronauts aboard the International Space Station Friday, about two hours after a worsening air leak in Russia's Zvezda service module prompted one of the station's rarest emergency alerts.

The episode exposed unresolved technical and diplomatic friction between NASA and Roscosmos over how to repair persistent leaks aboard the aging orbital platform, even as U.S. Congress weighs legislation to extend ISS operations through 2032.

Mission controllers issued the safe-haven order at 9:04 a.m. ET, directing crew members to shelter in the docked Crew Dragon spacecraft as the leak rate in Russia's Zvezda service module nearly doubled — rising from approximately 1 pound of air per day to 2 pounds per day, according to The Korea Times. NASA lifted the order roughly two hours later after assessing the situation.

Five of the station's seven crew members took shelter in the Crew Dragon: NASA astronauts Jessica Meir, Jack Hathaway and Christopher Williams, European Space Agency astronaut Sophie Adenot and Roscosmos cosmonaut Andrey Fedyaev. Two Russian cosmonauts — Sergey Kud-Sverchkov and Sergei Mikayev — remained aboard the station and did not follow the safe-haven procedures.

The emergency also laid bare a disagreement between the two agencies over repair methods. The Russian cosmonauts planned to use a saw to access the area around the crack, but NASA objected to the technique and ordered the safe-haven procedures instead, The Korea Times reported.

Russia detected two separate leaks in the Zvezda module. The first was sealed quickly, and crews were preparing to address the second. Roscosmos said there was no immediate threat to the crew or to station systems.

The ISS has operated for 27 years without ever requiring a crew evacuation. Safe-haven orders — directing astronauts to shelter in an attached spacecraft rather than abandon the station — are considered rare events in the program's history.

The incident comes as Congress considers legislation that would extend ISS operations through 2032. NASA and Roscosmos have debated the cause and remedy for small leaks in the station's aging Russian section for months.

"We look forward to working with Roscosmos on a collaborative approach to address the leaks," NASA spokesperson Bethany Stevens said.