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

Stereo photographs, called Kromograms, show the earthquake-damaged San Francisco of 1906. They are thought to be the first color photographs from one of the worst natural disasters in U.S. history. Frederick Eugene Ives/Smithsonian's National Museum of American History hide caption

itoggle caption Frederick Eugene Ives/Smithsonian's National Museum of American History