KENNEDY SPACE CENTER, FLA. - In the waning twilight, the service structures on Launch Pad 39B (left) and the Mobile Launcher Platform carrying Space Shuttle Discovery glow with lights. The Shuttle began rollout to the pad at 2:04 p.m. EDT from the Vehicle Assembly Building at NASA’s Kennedy Space Center, marking a major milestone in the Space Shuttle Program’s Return to Flight. Launch of Discovery on its Return to Flight mission, STS-114, is targeted for May 15 with a launch window that extends to June 3. During its 12-day mission, Discovery’s seven-person crew will test new hardware and techniques to improve Shuttle safety, as well as deliver supplies to the International Space Station.