(04/20/2000) --- A Shuttle Training Aircraft (STA) soars into the blue sky above Kennedy Space Center. The STA is a modified Grumman American Aviation-built Gulfstream II executive jet that was modified to simulate an orbiter's cockpit, motion and visual cues, and handling qualities. It is used by Shuttle flight crews to practice landing the orbiter. In flight, the STA duplicates the orbiter's atmospheric descent trajectory from approximately 35,000 feet altitude to landing on a runway. The orbiter differs in at least one major aspect from conventional aircraft; it is unpowered during re-entry and landing so its high-speed glide must be perfectly executed the first time there is no go-around capability. The orbiter touchdown speed is 213 to 226 miles (343 to 364 kilometers) per hour. There are two STAs, based in Houston