The Mir cosmonauts’ efforts to find and repair a small leak in the space station are paying off, with the internal pressure now stabilizing after a sealing plug was installed on the Spektr module’s hatch.

The sealing plug was used yesterday to replace a pressure gauge on the Spektr hatch door after cosmonauts detected the sound of escaping air.
Sergei Zalyotin and Alexander Kalery have been performing a step-by-step search for the small leak since arriving on Mir earlier this month – isolating the station section by section in order to pinpoint its location.

The leak is very small, and has never posed a problem for the mission. Mir’s previous crew first detected it in 1999, but those cosmonauts were not able to locate the leak before leaving the station last August.

The now-plugged hatch separates the unpressurized Spektr module from the rest of the pressurized Mir station. Spektr has been unpressurized since 1997, when an unmanned Progress cargo re-supply spacecraft ran into the module during a docking maneuver.

Repairing the leak is part of the first phase of work for the new Mir cosmonauts as they as they prepare the station for its extended life as a commercial and scientific facility in space.

The leak-related repair and monitoring are not the only activities performed by the crew today. They also worked with the Biostoikost materials science experiment.