CHAPTER 20 DAY IN THE LIFE: WHEN MAJOR ANOMALIES OCCUR 360 occurring in various sub-teams, with seven key sub-teams listed below: n EVAs: Planning spacewalks to fully restore the system by replacing the degraded Pump Module with a new spare this included writing down detailed steps to solve ammonia Quick Disconnect (QD) problems (connections in the system can be tricky) and planning for operations if the spacesuits become contaminated with ammonia n Cygnus: Determining whether the Cygnus launch and berthing could be safely accomplished without Loop A fully restored, especially if the EVAs take a while to develop n Troubleshooting: Continuing ground commanding to the system to see if temperatures could be controlled enough to allow for some temporary internal cooling, possibly allowing the Cygnus mission to occur before the EVAs, if needed n EMUs: Continuing the investigation into what had caused the water separator to clog in an EMU, which spacesuit components would be best to use, and any other actions needed for the spacesuits n Analysis: Predicting thermal and structural behavior of the systems with software modeling, known hardware performance and engineering experience for example, predicting the behavior of the ammonia in the loop at different temperatures and pressures n Planning: Planning the complex set of crew tasks and ground commanding sequence of events that would lead up to either a Cygnus-first scenario or an EVA- first scenario n Next Worst Failure: Determining impacts to the ISS and actions in case of a “Next Worst Failure,” essentially planning for the worst thing that could happen next before the loop was fixed The EVA officer, robotics officer, and SPARTAN briefed the expected operations for the spacewalks. It was by no means already figured out, but the teams had already changed out a Pump Module in 2010 and since then the procedures and crew training briefing had been updated and were fairly current. The flight director leading Team 4 announced the preliminary EVA schedule (should EVA be required) that had been sketched out on a whiteboard by the team the day before. The first spacewalk would need to be planned for December 19, just 6 days later, with the second and third EVAs occurring approximately December 21 and December 23, thus avoiding the high beta period starting December 30, and with the potential for three or more EVAs (Figure 3). This would leave a little bit of margin in the system if more time was needed between EVAs or if a fourth EVA was required. The EVA tasks that were involved are outlined Figure 3, assuming they could all be accomplished in three spacewalks. Normally, EVAs are planned over the course of months or years. Although a Pump Module was changed out in 2010, several issues had occurred during the last change-out that would need to be resolved, and teams had estimated 16 days for the ground team and crew preparations needed to prep the suits and tools and study for the EVAs. Pulling it off in 6 days was difficult to imagine. With the holidays quickly approaching, many wondered whether they would be working instead. U.S. Spacewalks Overview EVA 1: • Set up • Degraded Pump Module preparation: Quick Disconnect (QD) demate, Pump Module Jumper install, electrical connector demate • Spare Pump Module preparation: Multilayer insulation (MLI) open EVA 2: • Remove degraded Pump Module, install on Payload ORU • Remove degraded Pump Module, install on Payload ORU Accommodation (POA) • Install spare Pump Module - bolts and electrical connectors only EVA 3: • Finish spare Pump Module installation (Quick Disconnects) • Slow degraded Pump Module • Clean up Figure 3. This was the plan going into the series of EVAs. Astronauts would conduct three spacewalks. However, some tasks could take longer than anticipated thus, the team understood that up to four spacewalks could be needed to complete the repair.