Flight Engineers Rick Mastracchio and Mike Hopkins of the Expedition 38 have completed a spacewalk outside the International Space Station 12:29 EST on Saturday.
The 5-hour, 28 minute spacewalk is the first walk in a series of excursions scheduled to replace the broken ammonia pump module. The module is associated with the external cooling loops that maintain the optimum temperature for both internal and external equipment. The second spacewalk, originally scheduled on Monday, has been moved to Tuesday.
The one-day delay will allow the crew to resize their space suit for Mastracchio’s use. Mastracchio’s spacesuit was compromised while the crew was depressurizing the station’s airlock. The crew was studying whether some water has entered the suit’s sublimator which is inside the airlock. The flight control team at NASA’s Houston Center has decided to let Mastracchio use the backup spacesuit for the next scheduled spacewalk.
During the spacewalk done on Saturday, the two astronauts concentrated on removing the broken pump module from Loop A, the external Active Thermal Control System. This particular pump module encountered difficulties on December 11 when an external valve got stuck in an erroneous position, causing temperatures in the cooling loop to drop.
After he exited the airlock, Hopkins went to the worksite located at the center of the Starboard 1 truss segment. Meanwhile, Mastracchio connected himself to a foot restraint to enable Flight Engineer Koichi Wakata to fly him and position him correctly for various tasks.
Both Hopkins and Mastracchio spent a considerable amount of time demating the four ammonia fluid line. They have disconnected the fluid lines from the pump module to facilitate repair. After disconnecting the fluid lines, they attached them to a pump module jumper box, which will allow the ammonia to go to the system’s plumbing and keep both the ammonia and nitrogen in a liquid state.
Mastracchio now holds a record of 43 hours and 58 minutes of spacewalking, accumulated during seven spacewalks while Hopkins has 5 hours and 28 minutes of spacewalk during one expedition.
Watch the spacewalk video here.
