© NASAThe International Space Station, as seen in October 2018.
Crewmembers of the station's current Expedition 63 are in no immediate danger and will spend the weekend in the orbiting laboratory's Russian segment, inside the Zvezda service module, NASA officials said in an update today (Aug. 20).
Astronauts can work in a shirtsleeve environment inside the station, but the orbiting lab is never completely airtight; a little bit of air always leaks over time, requiring routine repressurization from nitrogen tanks that are sent up during cargo missions, NASA added in the update. (Space.com has reached out to NASA for comment and will update this story if and when the agency responds.)
This leak was first spotted in September 2019, when there were "indications of a slight increase above the standard air leak rate," NASA said in the statement. "Because of routine station operations like spacewalks and spacecraft arrivals and departures, it took time to gather enough data to characterize those measurements. That rate has slightly increased, so the teams are working a plan to isolate, identify and potentially repair the source."
While the leak rate is higher than usual, it is still within specifications for the station and poses no immediate danger to the crew, NASA officials emphasized. Astronauts also deal with leak simulations during training for their stays on the space station, which typically are about six months long.
"All the space station hatches will be closed this weekend so mission controllers can carefully monitor the air pressure in each module," NASA officials said. "The test presents no safety concern for the crew. The test should determine which module is experiencing a higher-than-normal leak rate. The U.S. and Russian specialists expect preliminary results should be available for review by the end of next week."
NASA astronaut Chris Cassidy and his Russian cosmonaut crewmates, Ivan Vagner and Anatoly Ivanishin, will stay in the Russian Zvezda service module from Friday night to Monday morning (Aug. 21 to Aug. 24).
The three astronauts will have "plenty of room," NASA officials said, noting that Zvezda was where crews first stayed when the ISS was under construction in the early 2000s. Further, the Expedition 63 crew will have access to the Poisk mini-research module and their Soyuz MS-16 crew ship while staying in Zvezda.
A different Soyuz vehicle that was attached to the orbiting lab suffered a leak back in 2018. Astronauts traced the cause to a small hole in the Soyuz's hull.
Editor's note: This is a developing story and will be updated with new details as they are available.
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In space, it would seem there's no such thing as a 'small' air leak.
Their PR reminds me of how they minimized deadly risks in the days before both Challenger & Columbia.
R.C.