Astronauts back on board ISS after repair to leak

Russia’s “Nauka” Multipurpose Laboratory Module is pictured shortly after docking to the Zvezda service module’s Earth-facing port on the International Space Station. — Russia’s “Nauka” Multipurpose Laboratory Module, shortly after docking to the Zvezda service module’s Earth-facing port on the International Space Station. Photo: NASA via CNN Newsource

Two Russian cosmonauts on board the International Space Station have completed the repair of one of two leaks that had caused concern.

NASA had directed the other five astronauts aboard the ISS to shelter inside a docked SpaceX craft while the repairs were done. That order has since been lifted.

The leak was caused by long-standing cracks in the Russian section of the space station. It follows earlier incidents of ISS leaks.

The cracks and leaks in a transfer tunnel between a module called Zvezda and a docking hatch have been a known concern for some time. But a NASA statement suggested the situation had potentially worsened.

“Following new leaks, Roscosmos has elected to proceed with a more extensive repair operation on Friday, June 5,” NASA press secretary Bethany Stevens said in an earlier post on X. “Out of an abundance of caution, NASA has directed all four of the agency’s SpaceX Crew-12 members and NASA astronaut Chris Williams to assume an elevated safety posture in the Dragon spacecraft while the repair is under way.”

The order to seek shelter was lifted later as the Russian space agency “paused Friday’s structural repair efforts … as more measurements and data is assessed”.

It is not yet clear when repair efforts will resume.

Those who sought shelter included all four members of the SpaceX Crew-12 mission who flew to the orbiting laboratory aboard the Dragon spacecraft: NASA’s Jessica Meir and Jack Hathaway, Sophie Adenot of the European Space Agency, and Roscosmos cosmonaut Andrey Fedyaev. NASA’s Chris Williams, who arrived at the ISS aboard a Russian Soyuz spacecraft, also sheltered with the Crew-12 astronauts.

Cosmonauts discovered two potential air leaks during an inspection, according to Russian state media. The Russian space agency, Roscosmos, said the situation did not pose a threat to the safety of the crew.

“While pressurising the Zvezda module’s transfer chamber (TBC) to the International Space Station’s pressure, specialists from the ISS Russian Segment’s main operations team detected a leak in the TBC,” a Roscosmos statement said, according to state media.

The first leak was quickly sealed, Russia’s Zvezda media outlet reported, while work on another problem area continued.

All five astronauts who sought shelter hunkered down inside the same 4 metre wide SpaceX Crew Dragon capsule that carried the Crew-12 group to the station in February.

Such a move is meant to prepare the astronauts for an emergency escape in the event of disaster. Astronauts routinely take shelter, for example, when the ISS passes near a piece of space junk or the station faces a catastrophic risk.

Leaks in the Russian-controlled segment of the space station have been a serious, looming issue for years as the rate at which the module has bled air has ebbed and flowed. The transfer tunnel that has caused concern has largely remained closed off from the rest of the space station to contain the problem.

However, after nearly a year without causing major issues, problematic leaks recently re-emerged. The directive to seek shelter may indicate the leak rate was worsening.

- CNN