Houston, June 18, 2026, 18:02 CDT
- Russia is likely to halt major repairs on the ISS’s leaking PrK transfer tunnel and keep the hatch closed, a move that would limit air loss but also limit how the crew can use the station.
- NASA put five astronauts into a SpaceX Dragon capsule on June 5, as Roscosmos prepared to cut a bracket close to suspected leak spots. After that, the crew went back to normal work.
- This comes as NASA is looking at a 2027 deadline to decide if commercial partners can step in for the ISS ahead of its scheduled 2030 end date, or if the station has to stay up longer.
NASA and Roscosmos look set to go with the simple route to deal with a persistent leak in a Russian part of the International Space Station. Instead of tearing apart aging equipment, the teams may end up just shutting the door on the leaking passageway.
Russia’s Zvezda service module has a small transfer tunnel called the PrK that connects to an aft docking port. Reports this week said the PrK could be decommissioned or kept unpressurized. NASA got concerned after a June 5 repair plan, leading to U.S.-side crew moving to a return capsule.
Station leak worries increase as NASA reports the PrK’s leak has picked up. Leak rates hit two pounds of air per day when Progress 95 was docked for cargo work. Roscosmos said they found new likely leak sites ahead of a deeper inspection.
Poor timing for NASA. This week the U.S. Government Accountability Office said the agency must decide by next year if a commercial station will be set before the ISS retires in 2030, or if NASA has to look at other options like keeping the ISS running longer.
NASA said Russia’s plan called for cutting a bracket to get closer to a suspected leak source, warning this “could have resulted in elevated risk” to nearby parts of the station. NASA responded by ordering the four SpaceX Crew-12 astronauts and NASA’s Chris Williams into Dragon, telling them to take up a “safe haven” position—crew inside the docked capsule, ready to head back to Earth if needed. NASA
NASA press secretary Bethany Stevens said then the step was “out of an abundance of caution.” Once Roscosmos stopped the repair in favor of taking new measurements, Stevens said NASA wanted a “collaborative approach” with the Russians. Spaceflight Now
Roscosmos gave another account. The agency said there were two leaks, one already plugged with a hermetic compound, and work ongoing to close the second. Roscosmos also said ISS pressure was steady, with no immediate danger to crew or systems.
Tension isn’t just over a single patch. A Progress cargo ship linked to Zvezda’s rear usually handles reboosts, the engine burns that keep the station in orbit. Sealing the PrK hatch might keep some fluid transfers running, but would also make it harder to reach cargo and put the spot’s load limits in doubt.
Sealing the PrK might let the station stay operational. ESA astronaut Andreas Mogensen told The Register last year that with the cracks isolated to the end chamber, Russia could give up that docking area and limit the impact on ISS functions. “You could seal it off,” he said. But Mogensen also pointed out more issues could come up. theregister
Commercial push is intensifying. NASA is in talks with firms building private stations after ISS, like Axiom Space, Blue Origin’s Orbital Reef, and Starlab. But the agency hasn’t locked in its acquisition plan for the handoff, the GAO said.
Clayton Swope, a space analyst at the Center for Strategic and International Studies, said in May the commercial-station business is still tied almost entirely to NASA demand. He called the agency “nearly the whole market.” So if the ISS is extended longer than planned, or if there’s a sudden loss of capability, it’s more than just a technical problem—it could determine which private stations last through the pause and get enough funding. CSIS
Cleaner downside to the Russian workaround: closing the PrK isn’t a fix. Air loss may drop, but it’s still unclear if new cracks will show up in Zvezda’s old structure. Options for docking and station-keeping get tighter as the ISS nears its end.
No word yet from either NASA or Roscosmos on a permanent shutdown of the PrK. The station remains up, but the dispute over the tunnel points to the bigger question: the ISS has to keep going until a replacement comes, and that’s looking less certain now.
