STS-120 Pilot George Zamka disembarks from the shuttle training aircraft, or STA, after successful landing practice on NASA's Shuttle Landing Facility runway. A modified Grumman American Aviation-built Gulf Stream II jet, the STA simulates an orbiter's cockpit, motion and visual cues and handling qualities. In flight, the STA duplicates the orbiter's atmospheric descent trajectory from approximately 35,000 feet altitude to landing on a runway. Melroy and other crew members are at Kennedy Space Center to take part in the terminal countdown demonstration test, which also includes a simulated launch countdown. Mission STS-120 is targeted for Oct. 23. Photo credit: NASA/Kim Shiflett