Late Monday night, the Expedition 63 crew was awakened by flight controllers to continue troubleshooting a small leak on the International Space Station that appeared to grow in size. Ground analysis of the modules tested overnight have isolated the leak location to the main work area of the Zvezda Service Module. Additional work is underway to precisely locate the source of the leak.
The leak, which has been investigated for several weeks, poses no immediate danger to the crew at the current leak rate and only a slight deviation to the crew’s schedule.
NASA astronaut and station commander Chris Cassidy and Roscosmos cosmonauts Anatoly Ivanishin and Ivan Vagner were instructed to move into the Russian segment to collect data at various locations in the Russian modules. The size of the leak identified overnight has since been attributed to a temporary temperature change aboard the station with the overall rate of leak remaining unchanged.
Previous leak checks were conducted in the U.S., European and Japanese modules in the U.S. segment of the station.
One by one, the crew closed hatches between Zvezda’s aft and forward sections and Zvezda’s passageways to the Pirs Docking Compartment and the Poisk module while using an ultrasonic leak detector to collect data. Throughout the night, pressure measurements were taken by U.S. and Russian specialists to try to isolate the source of the leak. At the completion of the overnight checks, the crew opened hatches once again between the U.S. and Russian segments and resumed regular activities.
The crew is preparing for this weekend’s arrival of the uncrewed Northrop Grumman Cygnus cargo craft which is scheduled for launch Thursday night from the agency’s Wallops Flight Facility, Virginia, as well as the upcoming launch of the next trio of residents for the station. NASA astronaut Kate Rubins and cosmonauts Sergey Ryzhikov and Sergey Kud-Sverchkov are at the Baikonur Cosmodrome in Kazakhstan, preparing for launch to the complex on October 14.