Actually, there won’t be any new solar arrays added to the International Space Station (ISS) on this mission. You may be thinking of the last Space Shuttle flight (Atlantis STS-115) which brought up the massive P3/P4 truss segment, weighing 35,000 pounds, with a new set of solar array wings that were unfurled stretching some 240 feet from tip to tip. The new solar arrays added on the Atlantis mission are shown in the picture below running from top to bottom of the picture.
However, the current mission of Space Shuttle Discovery (STS-116) is the most complex series of assembly tasks ever attempted by humans in space. The coordination between ground control, the crew aboard ISS, and the spacewalkers is an astounding ballet of complex tasks. They must all work together in exactly the required sequence to shut down power on the ISS, rewire the station from its initial temporary power configuration to the permanent configuration, and power up the ISS segments again.
Other tasks of special note during this mission will be the addition of the P5 spacer segment on the end of the port truss of ISS and retraction of half of the P6 solar array (the array above the ISS running left to right in the picture below). It must be retracted so that the new solar array added in the last mission can begin to rotate continuously in a complete circle to follow the sun as the ISS orbits the Earth. The rotating solar arrays are something I find very fascinating, as it will resemble a huge paddle-wheel craft in space.
