STS-116 crew members gather after completing the emergency egress procedure.

On the 195-foot level of the fixed service structure on Launch Pad 39B, STS-116 crew members gather after completing the emergency egress procedure. Seen here are Commander Mark Polansky (left) and Pilot William Oefelein (right). They and other crew members are practicing the emergency egress system to get off the pad, part of the prelaunch preparations known as terminal countdown demonstration test. The TCDT includes a simulated launch countdown and payload familiarization. The STS-116 mission is No. 20 to the International Space Station and construction flight 12A.1. The mission payload is the SPACEHAB module, the P5 integrated truss structure and other key components. Launch is scheduled for no earlier than Dec. 7. Photo credit: NASA/Kim Shiflett