The Expedition 23 crew photographed this view of the aft portion of space shuttle Discovery, including the three main engines, during a survey of the approaching vehicle prior to docking with the International Space Station. As part of the survey and part of every mission’s activities, the STS-131 Discovery crew performed a back flip as part of the rendezvous pitch maneuver. The image was photographed with a digital still camera, using a 400mm lens at a distance of about 600 feet, or 180 meters. Image Credit: NASA