The second try works like a charm as the Space Shuttle Discovery (STS-56) lifts off from Launch Pad 39B. The first attempt to launch was halted at T-11 seconds on April 6th. Aboard for the second shuttle mission of 1993 were a crew of five and the Atmospheric Laboratory for Applications and Science 2 (ATLAS 2), the second in a series of missions to study the sun's energy output and Earth's middle atmosphere chemical make-up, and how these factors affect levels of ozone.