(03/19/2002) -- With the external tank and solid rocket boosters of Space Shuttle Atlantis looming above them, the STS-110 crew takes a break during Terminal Countdown Demonstration Test activities to pose for a photo. . Standing left to right are Mission Specialists Jerry Ross, Rex Walheim and Lee Morin; Commander Michael Bloomfield; Mission Specialist Ellen Ochoa; Pilot Stephen Frick; and Mission Specialist Steven Smith. The TCDT, which includes emergency egress training and a simulated launch countdown, is held at KSC prior to each Space Shuttle flight. Scheduled for launch April 4, the 11-day mission will feature Shuttle Atlantis docking with the International Space Station (ISS) and delivering the S0 truss, the centerpiece-segment of the primary truss structure that will eventually extend over 300 feet