KENNEDY SPACE CENTER, Fla. -- After completing their driving training on the M-113 armored personnel carrier (behind them), the STS-118 crew take a break. From left are Mission Specialists Dave Williams and Rick Mastracchio, Commander Scott Kelly, Mission Specialist Barbara R. Morgan, Pilot Charlie Hobaugh, and Mission Specialists Alvin Drew and Tracy Caldwell. Williams represents the Canadian Space Agency. Morgan joined NASA's Teacher in Space program in 1985 and was selected as an astronaut in 1998. The crew is at Kennedy for the Terminal Countdown Demonstration Test (TCDT), a dress rehearsal for launch. TCDT activities include the M-113 training, payload familiarization, emergency egress training at the pad and a simulated launch countdown. The STS-118 payload aboard Space Shuttle Endeavour includes the S5 truss, a SPACEHAB module and external stowage platform 3. The mission is the 22nd flight to the International Space Station and is targeted for launch on Aug.7. NASA/George Shelton