On Launch Pad 39A at NASA's Kennedy Space Center in Florida, STS-125 Mission Specialist Mike Massimino discusses his role in the mission for the media. The crew is at Kennedy to take part in terminal countdown demonstration test, or TCDT, activities before launching on space shuttle Atlantis’ mission to service NASA’s Hubble Space Telescope. TCDT provides astronauts and ground crews with an opportunity to participate in various simulated countdown activities, including equipment familiarization, emergency training and a simulated launch countdown. Atlantis is targeted to launch Oct. 10. Photo credit: NASA/Kim Shiflett