CHAPTER 20 DAY IN THE LIFE: WHEN MAJOR ANOMALIES OCCUR 366 thrown by the EVA crew, it would be difficult to ensure the Pump Module would not come around and hit the ISS on a future orbit based on orbital mechanics. Also, it would need to be thrown in a direction that the EVA team thought would be tricky for the crew members, given the position of having their feet in the SSRMS. Reasons for keeping the degraded Pump Module were also surfacing in that the engineering team had been brainstorming ways to repair it in the future. So, the team turned off all work on jettison as part of a nominal course of action. Contingency jettison would still need to be worked in case a spacesuit emergency came up while the crew was holding the Pump Module. Tuesday, Dec 17, 2013— Decision Day The Radiator Return valve effort was not looking as promising as the EVA effort, so the ISS Program management decided to commit to performing the EVAs. Because there was risk to the Cygnus mission with Loop A unable to control temperatures, the ISS Program made the decision that the EVAs would occur first and the Cygnus mission would launch in January so that it would arrive after the high beta cutout. A fresh complement of ants and vaccine-related science would be loaded into the vehicle just prior to that January launch. At this point, a decision needed to be made regarding when the team would actually be ready for the first EVA. One key area in the “trade space” of the schedule was the issue of which spacesuit components would be worn by the crew and how much time it would take to get them ready. Over the course of the previous few days, the team looked at which spacesuit components had been exposed the least to contaminated water filters over the past few months. Ironically, the Primary Life Support System (PLSS) used by Parmitano (designated “3011”) had recently had a lot of components changed out due to the investigation of the water in the helmet. With all of its new spare parts, PLSS 3011 was actually considered one of the cleanest (i.e., not as contaminated), and one of the recommended spacesuit parts to be worn for the EVAs to recover Loop A. However, use of 3011 would require another 2 days to get the suit ready, which would push the first EVA to Saturday, December 21. Unlike the other recommended spacesuit, a spacesuit using PLSS 3011 would need to be resized using different modular parts to fit the current crew on board and change out of some of the components. The Hard Upper Torso and Secondary Oxygen Pack would need to be removed and replaced (see also Chapter 17). Hard Upper Torso sizing changes drive other changes, sometimes causing the need for different legs for the arms and legs, and the new parts and tweaks take time to put together. Despite the fact that a delay in the EVAs meant extending the risky posture of the ISS, the team agreed that these modifications and the use of that suit was the right thing to do to reduce the risk to the on-board crew. The teams working the crew schedule and EVA were relieved to have 2 more days and a single, manageable plan. Working Out the Extravehicular Activity Details As for the EVAs themselves, the team continued testing and finalizing the details. Some of the EVA issues that had to be addressed throughout this effort are shown in Table 1. An EVA team performed a test in the Neutral Buoyancy Laboratory to verify each crew member would be able to get back into the airlock quickly from each of the planned worksites in the event of another water-in-helmet scenario. The scenario is tricky since it combines several already-hazardous areas of spacewalking—turning off the water shuts off the cooling fan so the astronaut’s body might literally overheat taking steps to prevent overheating involve purging the oxygen in the suit, which significantly increases the risk of running out of oxygen. The team walked through the scenarios for these specific locations and to determine whether the crew needed help getting back to the airlock. Crew members had to get to the airlock approximately 30 to 40 minutes after the emergency was declared, depending on how much energy they were expending and how hot they might get (e.g., if they are “riding” on the SSRMS, or working harder by using their hands to translate). Mission Control simulations such as those described in Chapter 10 were also planned— i.e., a water-in-helmet case, along with ammonia contamination and simulating what would happen if a Next Worst Failure occurred. Also, the team began to discuss what would happen if the EVAs were not complete on time and whether an EVA would be needed to finish