At Launch Complex 39, STS-117 Pilot Lee Archambault is helmeted and ready to practice driving an M-113 armored personnel carrier. The astronauts on the STS-117 crew are participating in M-113 armored personnel carrier training during Terminal Countdown Demonstration Test (TCDT) activities, a dress rehearsal for their launch, targeted for March 15. The M-113 could be used to move the crew away from the launch pad quickly in the event of an emergency. The TCDT also includes pad emergency egress training and a simulated launch countdown. The mission payload aboard Space Shuttle Atlantis is the S3/S4 integrated truss structure, along with a third set of solar arrays and batteries. The crew of six astronauts will install the truss to continue assembly of the station. Photo credit: NASA/Kim Shiflett