CHAPTER 4 DAY IN THE LIFE: THE MAKING OF A MISSION 70 Therefore, a trade occurred among supplies and hardware for the ISS, supplies for the shuttle crew for an extra day, and the amount of work those additional astronauts could perform in the allotted time. An additional factor was that as the mission got longer, the team had to allow the crew a day off to rest. PMA 3 Node 3 Cupola HRS Dynamic Envelope (brown shading) 77.2 cm (30.4 in.) Clearance Images courtesy of MAGIK Robotic Analysis Team Figure 5. The PMA3 relocated on the port end of Node 3 (top), showing the tight clearance with the radiator (bottom) where the brown shading illustrates the dynamic clearance envelope of the moving radiator. Also around this time, the ECLSS team realized that with the many available hands of the shuttle and increment astronauts, significant progress could be made in relocating the regenerative life support and exercise racks that were destined to be installed. This promised to be a complicated task. Much of the US Segment life support system would have to be shut down, transferred, installed, and reactivated. This large amount of work had to be accomplished in as short a window as possible because of the critical need for life support and the additional demand of seven more people on the station at the time. Since the team had to add a day to the mission to relocate the PMA3, this provided an extra day to start the rack relocations (i.e., two crew would perform the PMA3 robotics operations while the remaining crews could work on configuring Node 3). It was assumed that the programs would find this worth the cost of adding supplies to the mission. By the end of the summer of 2009, the mission had grown to a 13-day mission. However, to be conservative and to allow for things going wrong, the additional day was considered optional and would be officially added to the timeline only during the flight if all was proceeding reasonably according to plan. If things did not work out well, these tasks would fall to future increments after the orbiter departed.