In Firing Room 4 of the Launch Control Center, Shuttle Launch Director Mike Leinbach (foreground) cheers over the successful liftoff of Space Shuttle Discovery, watching it rocket through the sky on mission STS-121 -- the first ever Independence Day launch of a space shuttle. At far left is Stephanie Stilson, NASA flow director in the Process Integration Branch of the Shuttle Processing Directorate, who began conducting Discovery's processing operations in December 2000. Liftoff was on-time at 2:38 p.m. EDT. During the 12-day mission, the STS-121 crew of seven will test new equipment and procedures to improve shuttle safety, as well as deliver supplies and make repairs to the International Space Station. Landing is scheduled for July 16 or 17 at Kennedy's Shuttle Landing Facility. Photo credit: NASA/Kim Shiflett