STS-124 Pilot Ken Ham stands ready to practice driving the M113 armored personnel carrier as part of emergency training. Behind him is Mission Specialist Karen Nyberg. Ham and other crew members are at NASA's Kennedy Space Center for a dress launch rehearsal called the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization and emergency training. On the STS-124 mission, the crew will deliver and install the Japanese Experiment Module – Pressurized Module and Japanese Remote Manipulator System. Discovery's launch is targeted for May 31. Photo credit: NASA/Kim Shiflett