31 DAY IN THE LIFE: LIVING AND WORKING IN SPACE AND ON THE GROUND CHAPTER 2 develop work-arounds in real time, as needed. A spacewalk may take 6 or more hours outside. Once the crew is back inside, a couple hours of work is required to get the airlock repressurized, get the crew members out of their suits, and (essentially) close up shop for the day. Vehicle dockings can be just as complex, especially for the ground team, although in most cases the ISS crew does not have as much of the workload as on an EVA day. In the weeks prior to the arrival of a visiting vehicle, the lead team assesses the ISS power requirements, reviews any station attitude control configuration changes or maneuvers needed for rendezvous, and looks at the trajectory of the incoming spacecraft to determine positioning constraints for any of the articulating appendages such as the robotic arm, solar arrays, or radiators. In most cases, the team needs to feather at least some solar arrays so that plumes from the thrusters of that vehicle do not hit the wrong part of the array, which could cause structural loading and/or contamination. Arrays that are feathered generally are not producing as much power as normal, so it might be necessary to turn some systems off to preserve margin on the batteries during the rendezvous, as discussed in Chapter 9. ISS systems are configured for the operation several hours ahead of the vehicle arrival (Figure 10). As much of the systems configuration as possible is done from the ground, but any system that the crew may use during approach will be set up by the crew. Depending on the vehicle, that may include video cameras, the robotic arm system, ship-to-ship communications and monitoring, or simply a still camera used by a crew member at a window facing the right direction. The crew will also prepare the hatchway(s) and pressure check hardware for use after docking. Figure 10. NASA Flight Director Dina Contella monitors the launch and docking of the Expedition 46/47 crew (Yuri Malenchenko, Tim Kopra, Tim Peake) on Soyuz from the Baikonur Cosmodrome in Kazakhstan on December 15, 2015. Back to Earth Figure 11. The Soyuz is seen as it lands with Expedition 43 Commander Terry Virts of NASA, cosmonaut Anton Shkaplerov of the Russian Federal Space Agency (Roscosmos), and Italian astronaut Samantha Cristoforetti from the European Space Agency near the town of Zhezkazgan, Kazakhstan, on June 11, 2015. As with any mission, the work does not end just because the crew has made it back to Earth, as seen in Figure 11. Unlike getting the astronauts from Houston to the launch site where the crews take commercial flights to Moscow and then a Russian Space Agency plane to the launch site, getting the crew back to Houston expeditiously is a major operation in itself. It is important to return the crews as quickly as possible to perform postflight medical studies and begin the rehabilitation to Earth’s gravity. NASA uses a Gulfstream G3 aircraft to fly the astronauts from Kazakhstan back to Houston (Figure 12). With a range of about 4,200 km (2,600 miles), the G3 cannot make the trip with a single crew due to the long duty day. Hence, it requires two flight crews of three personnel (two pilots and one flight engineer) to handle the long transit time of about 19 hours.