Space Shuttle Discovery clears the lightning mast and rockets into the blue sky on mission STS-121.

Making history with the first-ever launch on Independence Day, Space Shuttle Discovery clears the lightning mast and rockets into the blue sky on mission STS-121, trailing fiery exhaust. 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/Sandy Joseph & Robert Murray