The seven astronauts on the International Space Station got a scare Friday morning when air leaks worsened in a Russian module.
At about 9 a.m. Eastern time, NASA said the astronauts who had traveled to the I.S.S. in a SpaceX Crew Dragon capsule — two Americans, one Russian, one French — had been told to seek “safe haven” in the spacecraft, which was docked at the space station.
Another NASA astronaut who had arrived in a Russian Soyuz spacecraft joined them in the Crew Dragon, while two other astronauts from Roscosmos, the Russian space agency, prepared to make repairs.
“Following new leaks, Roscosmos has elected to proceed with a more extensive repair operation on Friday, June 5,” Bethany Stevens, the NASA press secretary, posted on social media.
The other astronauts were moved to the Crew Dragon “out of an abundance of caution,” she said.
About an hour and a half later, the immediate emergency was declared over. “Our counterparts in Roscosmos are standing down from any activities,” said Joseph Zakrzewski, a spokesman at the NASA Johnson Space Center in Houston.
“They are doing measurements only, so the crew aboard Dragon will be exiting the safe haven posture,” he added.
A tunnel in the Russian Zvezda module has suffered persistent leaking of air since 2019, raising concerns that microscopic cracks in the structure could lead to a catastrophic failure and decompression. As a precaution, the hatch to the tunnel was kept closed when not in use.
Repeated efforts to track down and repair the leaks appeared to have finally succeeded last year, but the leaks resumed last month.
In an update on Friday evening, NASA said that during operations this week involving a Russian cargo spacecraft, the leak rate had increased to two pounds per day.
After identifying areas where the leaks appeared to be occurring, Roscosmos decided to conduct a more extensive inspection and to perform a repair, which included cutting a bracket to provide access to the area.
That procedure increased the risk of a structural failure in Zvezda, NASA managers decided, leading to their decision to send the five astronauts into the Crew Dragon.
The Russians later changed their minds and did not perform the repair. Additional measurements and analysis will be performed instead. “NASA strongly supported that decision,” the space agency’s update said.
Operations on the space station have returned to normal, NASA said.
