Imagine you live in a house with walls that are just 2.54 mm thick. On the other side of your walls is certain death.
Now imagine that there’s a crack in the outer wall of your living room, with oxygen being sucked out. And you can’t fix it. Sounds pretty terrifying, doesn’t it?
But that’s exactly what has been going on aboard the International Space Station (ISS). For years.
Evacuation alert
Most recently, on June 5, five of seven astronauts on board the ISS were advised to take shelter in SpaceX’s Crew Dragon capsule due to a persistent leak that Russian cosmonauts were going to attempt to repair.
News of NASA’s instructions to take shelter made for some pretty scary headlines. “NASA orders astronauts on evacuation alert as space station air leak worsens,” was NBC News’s headline. CBC News’s own headline read, “NASA orders International Space Station astronauts to shelter, prepare for evacuation due to air leak.”
Now, the very word “evacuation” evokes a feeling of fear for life. But you wouldn’t have known it by listening to NASA ’s live feed on YouTube.
“All USOS [US Orbital Segment] crew members need to execute … Emergency Procedure 3.4: Crew Dragon, establish Safe Haven,” NASA mission control radioed to the crew. “If we need [you] to suit up, we will do that once we’re inside the Dragon.”
A recent air leak aboard the International Space Station prompted astronauts to prepare for a possible evacuation. Former NASA astronaut Chris Cassidy, who was aboard the ISS when a similar leak was first detected in 2020, breaks down emergency procedures and how astronauts respond to safety scares in orbit.
No panic. Just simple instructions.
Perhaps the reason is because that leak has been going on for years.
In fact, the reason they were told to shelter in Dragon was because the cosmonauts were making yet another attempt to repair it. And, as NASA spokesperson Bethany Stevens posted on X, they were advising the astronauts “out of an abundance of caution.”
The Zvezda service module transfer tunnel, known as PrK, has suffered from cracks and leaks for some time, and has been mitigated by Roscosmos as much as possible to date. The cracks have always been a concern that NASA watches very closely. NASA and Roscosmos have been working…
—NASASpox
Beyond its original lifespan
The first segment, the Russian Zarya, was launched in 1998, followed by the U.S. segment, Unity, and later Russia’s Zvezda. From 2000 onward, there has been a continual human presence on the station.
Initially, the ISS had a lifespan of 15 years, but it has far exceeded that and is showing its age.
But that doesn’t mean it’s done.
“NASA faces increasing risks to sustaining ISS operations through 2030. Ongoing cracks and air leaks in the Service Module Transfer Tunnel are a top safety risk,” a 2024 report from the Office of the Inspector General found.
It also explained that NASA and Roscosmos have been working together to mitigate the cracks that have appeared since 2019, though they are unsure exactly why the cracks have developed.
But the station exists in the harshest of environments. And that segment was one of the first launched.
“It’s going around the Earth every 90 minutes, half of it in darkness and half of it in light,” said space historian Chris Gainor. “And it’s not just the amount of sunshine; there’s sort of heat and everything else, and that wears things out.”
In order to deal with the persistent leak — which had gotten worse a month or so before the latest incident — astronauts close off that area and lower the air pressure, which helps slow it down. But they can’t close it off completely because it leads to one of the docking areas.
And that could be yet another reason for the cracks.
“You get thumping around and loads put on it when spacecraft are docking or undocking,” Gainor said.
NASA has announced that Expedition 75, the next crew to go to the International Space Station, will include Canadian Space Agency astronaut Joshua Kutryk. Kutryk, NASA astronauts Jessica Watkins and Luke Delaney, and Roscosmos cosmonaut Sergey Teteryatnikov will spend several months aboard the ISS.
Despite its age and its cracks, the life of the ISS has been extended to 2030, and NASA has said it wants a replacement station before it’s decommissioned. There are several private companies that are working on their own space stations, including commercial spaceflight company Axiom, which has conducted private missions to the ISS, one of which included Canadian Mark Pathy in 2022.
While NASA says the leaks pose a serious threat to the station, they seem confident that it is safe for their astronauts. And they have procedures in place — as was witnessed on June 5 — should an evacuation be needed.
As of now, the station is doing its job at protecting the astronauts. Sure, it’s had its share of problems, such as an ammonia leak, a near miss with space debris and a computer failure, but considering it has far outlived its original lifespan, it hasn’t faced anything so severe that it has warranted an evacuation. Astronauts from the U.S., Russia, Europe and Canada continue to conduct science experiments and advance technology.
And both NASA and Roscosmos have been keeping a close eye on the leak.
“I think 2030 is a reasonable time. You know, it’s not that far away,” Gainor said.
“I think they’re actually doing pretty good if this is the biggest problem they’ve got.”
That’s good news for Canadian Space Agency astronaut Joshua Kutryk, who’ll be launched to the ISS no earlier than September.
