Space shuttle Atlantis STS-122 Leland Melvin talks to the media following his arrival or TCDT activities.

Space shuttle Atlantis STS-122 Mission Specialist Leland Melvin talks to the media at Kennedy Space Center's Shuttle Landing Facility following his arrival to participate in three days of terminal countdown demonstration test, or TCDT, activities. The TCDT provides astronauts and ground crews with equipment familiarization, emergency egress training and a simulated launch countdown. On mission STS-122, Atlantis will deliver the Columbus module to the International Space Station. The European Space Agency's largest single contribution to the station, Columbus is a multifunctional, pressurized laboratory that will be permanently attached to U.S. Node 2, called Harmony. The laboratory will expand the research facilities aboard the station, providing crew members and scientists from around the world the ability to conduct a variety of experiments in the physical, materials and life sciences. Photo credit: NASA/George Shelton