319 DAY IN THE LIFE: RISKY AND REWARDING SPACEWALKS—SPACE SHUTTLE MISSION STS-120/ISS-10A CHAPTER 18 sparking/arcing occur and jump between the array and tools or the suit? Could the energized “plasma” environment of the ISS in its orbit aid in this arcing? Was there a better time to perform the repair relative to orbital sunrise/sunset to reduce the risk of shock—and how does wait time in the orbit trade against the risk of having Parazynski remain near the array while waiting for the perfect conditions? Figure 14. Repair technique development during STS-120/ISS-10A. Hinge stabilizing wires were called cufflinks because the crew would insert a thin 10 cm (4 in.) long aluminum plate through a hole, where it would catch on the other side. This plate was attached via a long wire to another plate that the crew would also thread through the array and into a hole on the other side of the damaged hinge. The first two figures show the insertion technique. The third photo shows the backside, where the wire is not visible but the aluminum plates are seen flat against the array. In the last photo, astronaut Steve Swanson tries out the technique while wearing an EVA glove to test whether Parazynski will be able to perform the technique while suited in the Extravehicular Mobility Unit. Figure 15. STS-120 pilot George Zamka holds up a cufflink that he and ISS Commander Peggy Whitson constructed on orbit in preparation for the 4B solar repair EVA. Because sunlight reflects off of the Earth and the ISS, the array could be energized even during orbital night. The team quickly decided the crew would only work from the passive side of the array (solar cells facing away from the crew). That did not avoid the danger completely—the array damage could still point part of a cell toward the crew member, exposing him to an electric charge. Parazynski’s huge suit or his floating tools might accidentally come in contact with the damage, especially if the array was swaying while he attempted to enact the repair. The team could imagine having him cut a wire and releasing some stored energy that would “twang” or oscillate and move the array.