The National Aeronautics and Space Administration (NASA) ordered five astronauts aboard the International Space Station (ISS) to shelter their spacecraft Friday morning, June 5, 2026.
The evacuation orders came as Russian cosmonauts attempted to repair a worsening air leak in the Russian segment of the station.
The four-member SpaceX Crew-12 crew, consisting of NASA astronauts Jessica Meir and Jack Hathaway, European Space Agency astronaut Sophie Adenot and Russian cosmonaut Andrey Fedyaev, as well as NASA astronaut Chris Williams, was invited at 9:04 a.m. ET to board the docked Crew Dragon spacecraft and don their spacesuits for a possible escape from the station.
After about two hours, NASA canceled the evacuation orders when it realized the leak rate was under control.
The leak was spotted in the transfer tunnel of the Russian Zvezda service module, which is an important structural element of the orbiting laboratory.
NASA has been concerned about cracks and air leaks for five years. NASA’s inspector general calls them a “major safety risk.” A senior NASA official confirmed that the leak rate had fallen from about 1 pound of air per day to 2 pounds.
The ISS maintains an atmosphere very similar to Earth’s at sea level, but not identical. The pressure is maintained at 14.7 pounds per square inch, with a composition of approximately 78% nitrogen and 21% oxygen. Air leaks are the escape of these gases through a crack into the vacuum of space.
For now, NASA has the situation under control. Russian cosmonauts Sergey Kud-Sverchkov and Sergei Mikayev accessed the cracked areas using saws. However, NASA officials disagreed with the chosen method, leading to the shelter-in-place order “out of an abundance of caution.”
However, if the breach grows beyond the station’s ability to compensate for the loss, pressure will be lost, oxygen levels will drop, and astronauts will suffer hypoxia (lack of oxygen) and decompression sickness, as divers do when they ascend too quickly.
However, long before this proves fatal, NASA will evacuate the entire space station using the docked spacecraft, rendering the ISS uninhabitable if the damage cannot be repaired. So while death may not be a problem, lack of breathable air poses the greater threat.
