Space Shuttle Discovery shoots into Florida's blue sky over the blue Atlantic Ocean, kicking off Fourth of July fireworks with its own fiery display. History was made with the first ever launch on Independence Day. It was the third launch attempt in four days; the others were scrubbed due to weather concerns. Liftoff on mission STS-121 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.