On Launch Pad 39A at NASA's Kennedy Space Center, STS-124 Mission Specialists Karen Nyberg (left) and Ron Garan have reached the slidewire baskets on the 195-foot level of the fixed service structure. The baskets are used for emergency egress, part of the launch dress rehearsal known as the terminal countdown demonstration test. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including a simulated launch countdown, equipment familiarization and emergency egress 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