The Smithsonian's Jon Blundell scans the fossilized foot bone — the metatarsal — of the Wankel T. rex to help create a digital 3-D image of the long-dead dinosaur. Nikki Kahn/The Washington Post hide caption

itoggle caption Nikki Kahn/The Washington Post

Discovery is sitting atop NASA's 747 Shuttle Carrier Aircraft, which will fly the shuttle from Florida to Virginia. Roberto Gonzalez/Getty Images hide caption

itoggle caption Roberto Gonzalez/Getty Images