of the spacewalk planned for the day. After venturing out of the Quest airlock into space, Mission Specialists Reilly and Olivas released launch restraints on the four Solar Array Blanket Boxes, which house the folded solar arrays. They made final attachment of bolts, cables and connectors, and began preparations for the activation of the truss. The two spacewalkers rotated the array canisters into their normal position for deployment on the next day. The start of the spacewalk was delayed for about an hour after the station temporarily lost attitude control when the station's control moment gyroscopes (CMGs) went offline. The spacewalk started after station's gyroscopes were initialized by flight controllers. EVA 1 marked the 84th devoted to the ISS assembly and maintenance. It was also the fourth for Reilly and first for Olivas. NASA's Mission Management Team also decided to extend Atlantis mission by two days and to add a fourth spacewalk. John Shannon, the head of NASA's STS-117 Mission Management Team during the day's mission briefing told reporters that the extra time would give the crew to complete the ISS assembly tasks and allow ground engineers to draw up plans to repair the damaged blanket on the OMS pod of Atlantis. NASA deemed that the torn blanket, while not a flight risk to the shuttle crew during reentry, could lead to some damage to the OMS pod's internal honeycomb-like graphite-epoxy structure. Such a damage would require additional time to repair once the Shuttle returns to Earth, NASA said. June 12 (Flight day 5 – Solar array deployment) The successful deployment of the S3/S4 solar arrays was the highlight of the day, adding significantly to the ISS power generation capabilities. Prior to crew wake up, station controllers began unfurling the solar array attached to the S3/S4 truss segment. Shuttle crew then took over, unfolding one wing at a time in stages, pausing to let the sunlight warm the solar array panels which helped to prevent the thin individual panels from sticking together. The crew finished unfolding the first wing at 11:29 am CDT and the second at 12:58 pm CDT. There were continuing problems with the station's electrically driven gyroscopes, the preferred, non-propulsive, method for controlling the ISS due to a problem with a Russian navigation computer. The navigation computer problem started when flight controllers attempted to turn attitude control over to the ISS computers after letting shuttle computers handle