Leak in ISS Russian Segment Increases, But Not an Immediate Concern

NASA said today the air leak in the Russian segment of the International Space Station has increased, but along with Russia’s Roscosmos stressed it does not present an imminent threat. The leak was first reported several years ago, but NASA and Roscosmos have downplayed it, insisting the affected section could be sealed off with little impact on ISS operations. Separately, NASA’s Aerospace Safety Advisory Panel reiterated the need for an ISS deorbit tug to ensure the ISS does not make an uncontrolled reentry at the end of its lifetime, whenever that is.

NASA ISS Program Manager Joel Montalbano revealed the increased leak rate at a news conference this morning prior to the launch of the next ISS crew, Crew-8, scheduled for early Friday morning.

Montalbano told reporters the leak rate has doubled from 1 pound per day to “a little over 2 pounds a day.” The rate increased “about a week before the recent Progress launch and docking,” referring to Russia’s Progress MS-26 cargo resupply spacecraft that launched on February 14 (which NASA designates as Progress 87).

The cargo was off-loaded from Progress MS-26 and the hatches now are closed to that part of the ISS so it is “not an impact right now on Crew-8 or vehicle operations, but something for everyone to be aware of,” Montalbano said.

The ISS is a partnership among the United States, Russia, Canada, Japan, and 11 European countries participating through the European Space Agency, with each providing its own modules or other hardware.

The air leak was first identified in 2020 and traced to Russia’s Zvezda module, also called the Service Module. Launched in July 2000, Zvezda serves as crew quarters on the Russian segment and has a tunnel connecting to a docking port.

Montalbano said the hatch that connects Zvezda and the docking port will remain closed until early April. “We’re working with our Russian colleagues on the next steps.”

Last November, ISS Program Director Robyn Gatens said she wasn’t worried about a catastrophic event because the worst that could happen is that the docking port would become unusable.

Roscosmos cosmonaut Oleg Kononenko, who is aboard the ISS right now on his fifth spaceflight and just broke the world record for total cumulative time in space (878 days), told Russia’s official news agency TASS the leak poses no threat to the crew.

“Indeed, there is an air leak from the service module’s transfer chamber. The leak poses no threat to the crew’s security. The flight continues as usual. In addition to carrying out scientific experiments, I was tasked with search and localization of the leak. The search situation is complicated by the numerous equipment installed in the chamber and the small size of the cracks.” – Oleg Kononenko

The bottom line is that the ISS is old and getting older. The first modules, Russia’s Zarya and the U.S. Unity, were launched in 1998 and the 420 Metric Ton laboratory has been permanently occupied with international crews rotating on roughly 4-6 month schedules since November 2000.

NASA has reached agreement with Canada, Japan and Europe to continue operating ISS until 2030 when it expects commercially-developed space stations to be ready to replace it. Russia has agreed only until 2028 in part because of concern about the technical integrity of its modules.

NASA’s Aerospace Safety Advisory Panel (ASAP) has been raising a red flag for several years about the need for NASA to develop a deorbit tug to send the ISS safely into an unpopulated area of the Pacific Ocean at the end of its lifetime, whenever that is. NASA had been planning to use Russian Progress vehicles to execute a deorbit plan, but the tense political climate following Russia’s invasion of Ukraine in February 2022 called that into question.

In October 2022, ASAP cautioned NASA that it needed to come up with a new plan. ASAP has reiterated that warning since then, including today as part of a public briefing on its first quarter 2024 review of NASA’s programs.

Lt. Gen. Susan Helms (Ret.), a former NASA astronaut and the new chair of ASAP, said they had not gotten an update on ISS as part of this quarter’s review, but called the need for an ISS deorbit capability “probably one of the most urgent safety issues” the panel sees right now.

“The panel is adamant that a deorbit capability for the International Space Station has to come to fruition. We are interested in both a deorbit capability for the end of life of the space station as well as getting some discovery done about what could be done now in the event that there’s some sort of contingency. …

“This is probably one of the most urgent safety issues that we see in the near term right now. … We reiterate that is something the panel is very concerned about.”

NASA’s FY2024 budget request includes $180 million to begin development of a deorbit tug, but with an estimated cost of $1 billion at a time of budget cutbacks and delays in finalizing appropriations, it’s not clear when or if that will happen.