Commander Brent Jett dons his launch suit before flying the Shuttle Training Aircraft to practice landing the shuttle.

STS-115 Commander Brent Jett dons his launch suit before flying the Shuttle Training Aircraft to practice landing the shuttle. STA practice is part of launch preparations. 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 STA duplicates the orbiter’s atmospheric descent trajectory from approximately 35,000 feet altitude to landing on a runway. Because the orbiter is unpowered during re-entry and landing, its high-speed glide must be perfectly executed the first time. Mission STS-115 is scheduled to lift off about 12:29 p.m. Sept. 6. Mission managers cancelled Atlantis' first launch campaign due to a lightning strike at the pad and the passage of Tropical Storm Ernesto along Florida's east coast. The mission will deliver and install the 17-and-a-half-ton P3/P4 truss segment to the port side of the integrated truss system on the orbital outpost. The truss includes a new set of photovoltaic solar arrays. When unfurled to their full length of 240 feet, the arrays will provide additional power for the station in preparation for the delivery of international science modules over the next two years. STS-115 is expected to last 11 days and includes three scheduled spacewalks. Photo credit: NASA/Kim Shiflett