Tow boats secure the Pegasus barge at the turn basin dock in the Launch Complex 39 Area at NASA's Kennedy Space Center. Onboard the barge is the external tank No. 123, designated to launch Space Shuttle Discovery on mission STS-116 in December. At left is the 525-foot-high Vehicle Assembly Building where the external tank will go after offloading from the barge. The tank, which was shipped from NASA's Michoud Assembly Facility in New Orleans, has undergone major safety changes, including removal of the protuberance air load ramps. Mission STS-116 will deliver the P5 truss segment, a SPACEHAB module and other key components to the International Space Station. Launch is currently scheduled no earlier than Dec. 14. Photo credit: NASA/George Shelton