The three Expedition 63 crew members living aboard the International Space Station will spend the weekend inside the orbiting lab’s Russian segment. Commander Chris Cassidy and his crewmates Ivan Vagner and Anatoly Ivanishin will stay in the Zvezda service module from Friday night into Sunday morning.
The station’s atmosphere is maintained at pressure comfortable for the crew members, and a tiny bit of that air leaks over time, requiring routine repressurization from nitrogen tanks delivered on cargo resupply missions. In September 2019, NASA and its international partners first saw indications of a slight increase above the standard cabin air leak rate. 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. The leak is still within segment specifications and presents no immediate danger to the crew or the space station.
All the space station hatches will be closed this weekend so mission controllers can carefully monitor the air pressure in each module. 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.
The three station residents will have plenty of room in Zvezda this weekend. The module provides the living quarters that enabled permanent human habitation to begin nearly 20 years ago when the Expedition 1 crew arrived at the station Nov. 2, 2000. Cassidy, Vagner, and Ivanishin also will have access to the Poisk mini-research module and their Soyuz MS-16 crew ship for the duration of their stay.