NASA puts ISS astronauts on evacuation alert after worsening air leak
The issue involves Russia’s Zvezda service module, one of the key structures of the football field-sized laboratory jointly operated by NASA and Russia’s space agency Roscosmos.
In this image from NASA TV, a SpaceX capsule carrying four astronauts docks at the International Space Station Friday, March 3, 2023. A new crew arrived at the International Space Station on Friday for a six-month mission, after overcoming trouble with one of the capsule’s docking hooks. (NASA TV via AP)
Astronauts aboard the International Space Station (ISS) were ordered by NASA to shelter inside their spacecraft and prepare for a possible evacuation as a Russian crew attempted to fix a worsening air leak on its portion of the orbital laboratory, news agency Reuters reported.
The four astronauts of NASA’s Crew-12 mission, NASA astronauts Jessica Meir and Jack Hathaway, European Space Agency astronaut Sophie Adenot, and Roscosmos cosmonaut Andrey Fedyaev, were instructed by NASA mission control at 9:04 a.m. ET Monday to enter their docked Crew Dragon spacecraft and put on their spacesuits in case the leak required an emergency evacuation, a NASA official said.
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NASA later ends ‘safe haven procedures’
NASA spokesperson Bethany Stevens later said the agency had instructed astronauts “to end safe haven procedures” and return to planned operations aboard the ISS after Roscosmos paused its structural repair efforts.
Russia’s state space corporation Roscosmos said experts had detected two oxygen leaks aboard the ISS, but there was no immediate threat to the crew, according to Interfax news agency. The first leak was quickly sealed, while preparations were underway to seal the second one.
In orbit · 400 km up
Crisis and stand-down aboard the
ISS Air-Leak Scare
Crew of 7 · 3 nations · Russia's Zvezda service module · NASA + Roscosmos
09:04 ETSpacesuit order issued
ThenSheltered in Crew Dragon
LatestStood down — ops resumed
Seven aboard, three nations
7Crew AboardLiving & working on ISS
3NationsUS · Russia · France
5Told to ShelterCrew-12 four + Williams
The Crew-12 four
Jessica MeirNASA · USA
Commander
Jack HathawayNASA · USA
Pilot
Sophie AdenotESA · FRANCE
Mission Specialist
Andrey FedyaevROSCOSMOS · RUSSIA
Mission Specialist
Chris WilliamsNASA astronaut — fifth crew member directed to shelterAlso sheltered
Crew-12 = SpaceX's 12th crew rotationSeven astronauts are aboard in all. Five — the Crew-12 four plus Chris Williams — were directed to shelter; the other two were not named in this update.
The leak that doubled
Air loss from Zvezda — per day
1 lbRecent months
▸
2 lbFrom Monday
▲ Rate doubled on Monday
What is Zvezda?A Russian service module — a key structure of the football-field-sized orbital laboratory, where the air leaks have been occurring.
A months-long disputeNASA and Roscosmos — the station's two primary operators — have debated the cause and the fix for these small air leaks for months.
Roscosmos' accountTwo leaks were detected. The first was quickly sealed; work is underway to seal the second. Roscosmos says there is no immediate threat to the crew. (via Interfax)
The cracks have always been a concern that NASA watches very closely.— Bethany Stevens, NASA spokesperson (@NASASpox)
What 'safe haven' means
In a safe-haven response, the crew retreats into a docked spacecraft that can double as a lifeboat — sealed off and ready to undock and head home at short notice if a threat worsens. Here, that vehicle was the SpaceX Crew Dragon.
09:04 a.m. ET · MondayOrder from mission controlNASA mission control directs the Crew-12 astronauts to act on the worsening leak.
Into the capsuleEnter Crew Dragon, don spacesuitsThe crew enters the docked Crew Dragon and puts on spacesuits.
Shelter modePrepare for possible evacuationCrew shelters and stands ready to leave while the Russian side works the leak.
Stand-downSafe haven procedures endNASA asks the crew to end safe haven procedures and return to planned operations.
Where things stand
De-escalated — not closed outCrew stood down after Roscosmos paused its structural repair work; no immediate threat reported.
Resolved
First of the two leaks quickly sealed
Crew out of shelter, back to planned operations
Roscosmos: no immediate threat to the crew
Still open
Second leak — sealing still in progress
Repairs were paused, not completed
Months-long cause-and-fix dispute unresolved
The bottom lineThe emergency posture was lifted, but the underlying leak — and the long-running disagreement over how to fix it — has not been closed out.
Sources: Reuters · NASA (@NASASpox) · Roscosmos via Interfax | Compiled from live coverage
Leak linked to Russian Zvezda module
The issue involves Russia’s Zvezda service module, one of the key structures of the football field-sized ISS jointly operated by NASA and Russia’s space agency Roscosmos. The two agencies have reportedly debated for months over the cause of recurring small air leaks and possible fixes.
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“The cracks have always been a concern that NASA watches very closely,” Stevens said in a post on X.
According to a senior NASA official who spoke on condition of anonymity, the leak escalated on Monday from a pound of air loss per day to two pounds.
Who is aboard the ISS?
NASA’s Crew-12 mission is the 12th crew rotation mission of SpaceX’s human space transportation system. The ISS is currently home to seven astronauts from the United States, Russia and France.
Fedyaev, Hathaway, Meir and Adenot in Cape Canaveral, Florida, February 13, 2026. (REUTERS)
NASA describes the ISS as “a microgravity laboratory for researching new technologies and breakthroughs not possible on Earth”. The station, operated by five space agencies from 15 countries, has been continuously occupied since November 2000.
In this image from NASA TV, a SpaceX capsule carrying four astronauts docks at the International Space Station Friday, March 3, 2023. A new crew arrived at the International Space Station on Friday for a six-month mission, after overcoming trouble with one of the capsule’s docking hooks. (NASA TV via AP) 
Fedyaev, Hathaway, Meir and Adenot in Cape Canaveral, Florida, February 13, 2026. (REUTERS)
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