Space Shuttle Discovery, atop the mobile launcher platform and the crawler-transporter underneath, arrives on Launch Pad 39B for launch of mission STS-116. The 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. The launch window for mission STS-116 opens Dec. 7. Photo credit: NASA/Amanda Diller