On its slow journey via the crawlerway to Launch Pad 39B, Space Shuttle Discovery passes the turn basin.

On its slow 4.2-mile journey via the crawlerway to Launch Pad 39B, Space Shuttle Discovery passes the turn basin. In the foreground on the south side of the basin is the flag near the NASA News Center. The shuttle rests on a mobile launcher platform that sits atop a crawler-transporter. First motion in NASA's Vehicle Assembly Building was at 12:45 p.m. EDT. The rollout is an important step before launch of Discovery on mission STS-121 to the International Space Station. Discovery's launch is targeted for July 1 in a launch window that extends to July 19. During the 12-day mission, Discovery's crew will test new hardware and techniques to improve shuttle safety, as well as deliver supplies and make repairs to the station. Photo credit: NASA/Debbie Kiger