A worsening air leak aboard the International Space Station forced five astronauts to take shelter and prepare for evacuation for about two hours Friday as Russia attempted to repair a crack in its part of the orbital laboratory, NASA said.
The four astronauts from NASA’s Crew-12 mission aboard the station — two Americans, a French astronaut and a Russian cosmonaut — along with another American astronaut, were ordered by NASA Mission Control at 9:04 a.m. ET (1304 GMT) on Friday to enter their SpaceX-built Crew Dragon spacecraft docked at the station, NASA spokeswoman Bethany Stevens said.
NASA reversed that order about two hours later and told the astronauts they could return to the station while the agency and its Russian counterparts examined the air leak rate.
NASA and the Russian space agency Roscosmos, the station’s two main operators, have debated for months about the cause and possible solutions to small air leaks aboard the Russian Zvezda service module, a key structure of the ISS, a football-field-sized 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 underway to seal the second, Roscosmos said, adding there was no threat to the spacecraft’s systems.
Air leaks have been relatively minor in recent months, but on Friday they increased from one pound of air per day to two pounds, according to a senior NASA official who asked not to be identified.
The ISS currently hosts seven astronauts from two missions, including the Crew-12 team: NASA astronauts Jessica Meir and Jack Hathaway, European Space Agency astronaut Sophie Adenot and Roscosmos cosmonaut Andrey Fedyaev, who arrived in February.
The other crew, consisting of an American astronaut, Christopher Williams, and two cosmonauts, Sergey Kud-Sverchkov and Sergei Mikayev, arrived in November.
Kud-Sverchkov and Mikayev, who did not execute evacuation procedures, planned to use a saw to reach an area where they believe they can access the crack that is leaking air, the NASA official said. NASA officials did not agree with this method, the NASA official said, leading mission control in Houston to order safe haven procedures.
Stevens said NASA reversed the safe haven order and told astronauts they could return to the space station once Roscosmos stopped its efforts to repair the crack. “We look forward to working with Roscosmos on a collaborative approach to address the leaks,” he said.
Safe haven orders are rare on the International Space Station, although pieces of space debris at risk of colliding with the ISS and minor changes in air leak rates have triggered the process in recent years. Astronauts have never had to evacuate the ISS in its 27-year history.
The US Congress is considering legislation that would extend the expected life of the space station by two years, to 2032, to give companies more time to develop a replacement.
The bill is supported by Sen. Ted Cruz, a Republican, and Sen. Maria Cantwell, a Democrat, chairwoman and ranking member, respectively, of the Senate Commerce, Science and Transportation Committee. The legislation is part of the committee’s focus on rivaling China’s growing footprint in space.
Leaders of the U.S. Senate and House of Representatives are working to reach consensus on the proposed legislation.
