NASA pump repair successful

From NASA Reports

     Astronauts Rick Mastracchio and Mike Hopkins completed a second spacewalk to install a spare ammonia pump module on Christmas Eve.

     Their main tasks included the removal and installation of a spare pump module. The first task was to remove the spare pump module from an external stowage platform. After that was complete, the module was bolted to a truss and connected to Loop A of the station’s external thermal control system.

     Hopkins attached himself to the space station's arm and took a ride to the worksite. Mastracchio tethered himself to the station to assist his partner. Japanese astronaut Koichi Wakata operated the arm from inside the station.

     While doing the connection work, the duo uncoupled ammonia fluid lines from a jumper box that enabled ammonia flow during the repair spacewalks. After experiencing some difficulty disconnecting a fluid line the spacewalkers reported seeing ammonia flakes escaping a valve. As a precaution, mission controllers asked the spacewalkers to inspect their spacesuits for possible ammonia contamination. Once they were back in the airlock the duo conducted more ammonia decontamination procedures on their spacesuits. All four fluid lines were successfully reconnected to the newly installed pump module restoring ammonia flow.

     Afterward, Hopkins and Mastracchio completed electrical connections to the pump module. Power was successfully restored to the ammonia pump module. However, flight controllers will perform more tests before restarting the pump and returning it to full functionality.

     The duo was originally scheduled to finish the installation work on Monday before mission controllers detected a spacesuit configuration issue at the end of Saturday’s spacewalk, in which the spacewalkers removed a faulty pump that experienced a problem with its internal flow control valve Dec. 11.

     The suspect pump was removed from the starboard truss and parked in a temporary location on the station’s rail car where it can stay until at least next June. Managers decided an extra day of preparation was necessary to get a backup spacesuit ready for Mastracchio.