On the Shuttle Landing Facility at NASA's Kennedy Space Center, the commander of the STS-124 mission, Mark Kelly, sits in the cockpit of the shuttle training aircraft, or STA. He is getting ready to practice landing the shuttle on the SLF runway. The STA is a Grumman American Aviation-built Gulf Stream II jet that was modified to simulate an orbiter's cockpit, motion and visual cues, and handling qualities. In flight, the aircraft duplicates the orbiter's atmospheric descent trajectory from approximately 35,000 feet altitude to landing on a runway. Space shuttle Discovery is scheduled to lift off on the STS-124 mission at 5:02 p.m. May 31. Photo credit: NASA/Kim Shiflett