Astronauts take shelter as air leaks worsen on International Space Station

A worsening air leak aboard the International Space Station prompted five astronauts to take shelter and prepare for evacuation for roughly two hours on Friday as Russia attempted to ‌fix a crack on its portion of the orbital laboratory, Nasa said.

The four astronauts of Nasa’s Crew-12 mission aboard the station – two Americans, a French astronaut and a Russian cosmonaut – along with another US astronaut were ordered by Nasa mission control at 9.04am on Friday to enter their SpaceX-built Crew Dragon spacecraft docked to the station, Nasa spokeswoman Bethany Stevens said.

Nasa reversed that order roughly two hours later and told the astronauts they could return to the station as the agency and its ⁠Russian counterparts examined the rate of leaking air.

Nasa and Russia’s space agency Roscosmos, the station’s two primary operators, have debated for months ‌over the cause and potential fixes of small air leaks aboard Russia’s Zvezda service module, a key structure of the ISS, a football field-size orbital laboratory where astronauts live and work in space.

Roscosmos said on Friday that ‌its experts had detected two leaks aboard the ISS but that there was no immediate threat to the crew. The ⁠first leak was quickly sealed, ⁠and preparations were under way to seal the second one, Roscosmos said, adding that there was no threat to the spacecraft’s systems.

The air leaks have been relatively minor in ‌recent months but escalated on Friday from a pound of air (about 450 grams) per day to two pounds, according to a senior Nasa official who asked not to be named.