The Zvezda service module, launched in 2000, provides living quarters and also performs some of the functions of the life support system.
National Aeronautics and Space Administration (NASA)
NASA and the Russian space agency Roscosmos have yet to resolve the long-running and festering problem of leaks on the International Space Station.
The microscopic structural cracks are inside the small PrK module in the Russian segment of the space station, as well as in the airlock and stowage of the Progress spacecraft. Zvezda After the leak rate doubled over a two-week period earlier this year, Russia experimented with intermittently closing the hatch leading to the PrK module and conducted other investigations, but none of these measures taken in the spring were effective.
“Following leak troubleshooting activities in April 2024, Roscosmos closed the hatch. Zvezda “Progress is closed when not needed for cargo operations,” a NASA spokesperson told Ars. “Roscosmos continues to limit operations in the area and has taken steps to minimize risk to the International Space Station if its use is necessary.”
What are the actual risks?
NASA officials, both publicly and in meetings with the ISS’s outside stakeholders, have downplayed the seriousness of the risk of a leak, and at this time, it does not pose an existential risk to the space station. In a worst-case scenario of a structural failure, Russia could permanently close the hatch leading to the PrK module and rely on a separate docking port for Progress resupply missions.
But there seems to be growing concern about the ISS program at NASA’s Johnson Space Center in Houston. The space agency often uses a 5×5 “risk matrix” to classify the likelihood and consequence of risks to spaceflight activities, and a Russian leak is currently classified as a “5” for both high likelihood and high consequence. The possibility of that “catastrophic failure” has been discussed at the meeting.
A NASA spokesperson declined to make program leaders available for an interview in response to emailed questions from Ars. The ISS program is currently managed by former flight director Dana Weigel. Weigel replaces Joel Montalbano, who recently became deputy assistant administrator for the Space Operations Mission Directorate at NASA Headquarters in Washington.
A source familiar with NASA’s efforts to address the leaks confirmed to Ars that there are serious internal concerns about the issue. “Basically, we’re hearing that the program office has a fire that’s out of control and is working to resolve it,” the person said. “Joel and Dana have been quiet about the issue.”
U.S. officials are likely keeping quiet about their concerns because they don’t want to embarrass their Russian partners. Cooperation between the two countries has improved since the ouster of Russia’s pugnacious space leader, Dmitry Rogozin, two years ago. The current head of the Russian Space Agency has maintained cordial relations with NASA, despite rising geopolitical tensions between Russia and the United States over the war in Ukraine.
Leaks are a sensitive issue. Russia’s war effort will likely keep resources available for its civilian space program flat or even declining for the next few years. A core of Russian officials who value cooperation with the International Space Station are trying to “make do” with what they have to maintain the Soyuz and Progress spacecraft that carry crew and cargo to the station, and the station’s infrastructure. But they can’t afford major new investments, so they’re left to patch things up as best they can.
Aging infrastructure
At the same time, the space station is aging. Zvezda The module was launched nearly 25 years ago on a Russian Proton rocket in July 2000. The cracking problem first appeared in 2019 and has continued to worsen since then. The cause is unknown.
“Several leaks have been repaired, but additional leaks remain,” a NASA spokesperson said. “Roscosmos has not yet determined the root cause of the cracks, making it difficult to analyze or predict their future formation and growth.”
NASA and Russia have maintained a space station partnership since Russia’s invasion of Ukraine in February 2022. The U.S. large segment relies on the Russian segment for propulsion to keep the space station at altitude and maneuver to avoid debris. Since the invasion, the U.S. could have taken obvious steps to mitigate this, such as funding the development of its own propulsion modules or increasing the budget for building new commercial space stations to maintain a presence in low Earth orbit.
Instead, NASA’s senior officials have chosen to stay the course and work with Russia for as long as possible to maintain a fragile partnership with Russia and keep the aging but venerable International Space Station flying. It remains to be seen whether structural, diplomatic or other cracks will cause a rift in this effort before the station’s scheduled retirement in 2030.
