(03/14/1997) --- Three members of the STS-83 flight crew head toward the orbiter access arm on the 195-foot level Launch of Pad 39A that will take them to the crew hatch of the Space Shuttle Columbia during Terminal Countdown Demonstration Test (TCDT) exercises for that mission. Mission Specialist Donald A. Thomas is in the center of the group. Other crew members on the 16-day Microgravity Science Laboratory-1 (MSL-1) mission are: Mission Commander James D. Halsell, Jr.; Pilot Susan L. Still; Payload Commander Janice Voss; Mission Specialist Michael L.Gernhardt; and Payload Specialists Gregory T. Linteris and Roger K. Crouch