Center in Greenbelt, Maryland. Mather was honored for his work on the big-bang theory. Christer Fuglesang also held a short speech in Swedish, encouraging Swedes and others to aspire to become future astronauts. The EVA concluded at 03:07 UTC on the morning of December 13, and lasted for 6 hours and 36 minutes in total. During the spacewalk, after taking a close look at imagery gathered on the first three days of the flight, mission managers determined that the shuttle's heat shield would support a safe return to Earth. They also decided a more detailed inspection that had been scheduled for later in the mission would not be necessary. Three more spacewalks, one of which was unplanned, were required to reconfigure and redistribute power on the station, so that the solar arrays installed during STS-115 could be used. The first step of reconfiguring the power took place Wednesday when the port solar array on the P6 truss was retracted, which allowed the activation and rotation of the Solar Alpha Rotary Joint on the P4. The rotary joint allows the solar arrays on the P4 to track the Sun. The astronauts were required to spend the night sleeping in protected areas in order to avoid radiation from a solar flare eruption. December 13 (Flight day 5 – Solar Array Reorganization) Flight day 5 began for the astronauts at 15:21 UTC. The most high-profile activity was the attempted retraction of the P6 port-side solar array. The process began at 18:28 UTC, but problems with the array folding due to 'kinks' and 'billows' led the controllers to redeploy the array (from about 40% retracted). There then followed a series of more than 40 commands to furl and unfurl the arrays in an effort to get them properly aligned and folded. At 00:50 UTC, the retraction efforts were abandoned for the day. The problems, which appear to have been caused by a loss of tension in the solar array guide wires, had still not been solved, although 14 of the 31 bays on the array had been retracted (leaving 17 bays extended). This was enough to leave the port side arrays in a safe position to commence the activation of the Solar Alpha Rotary Joint (SARJ) at 01:00 UTC, allowing the solar arrays on the P3/P4 truss to rotate to follow the sun. December 14 (Flight day 6 – EVA #2) Flight day 6