Mission Specialists Drew Feustel and Mike Fincke are conducting the mission’s second spacewalk today, set to begin at 2:16 a.m. EDT, or earlier if the crew is ready sooner. Fellow crew member Greg Chamitoff, who conducted the first spacewalk with Feustel on Flight Day 5, will act as the Intravehicular Officer for today’s excursion, coordinating activities between the spacewalking astronauts and Mission Control. Meanwhile, Pilot Greg Johnson and space station crew member Cady Coleman will operate the station and shuttle robotic arms.
The first task of the day will be to refill one of the station’s cooling loops with ammonia. Feustel and Chamitoff completed much of the preparation for this task during the mission’s first spacewalk. They will first finish rerouting the cables to create a continuous open line from the P1 segment of the station’s truss, where the extra ammonia is stored in ammonia tank assemblies, to the P6 section where the leaky loop is. After the flight controllers on the ground in Houston perform a leak check to confirm the line is good, the refill will begin. About five pounds of ammonia will be added to the cooling loop. Once the refill is complete, Feustel will vent the remaining ammonia from the jumper cables then remove the cables.