Stock Photo - 06/23/1999 _ STS_93 Mission Specialists Catherine G. Coleman Ph.D. and Steven A. Hawley Ph.D., and Commander Eileen M. Collins watch and listen to Bob Parks, a Safety Egress trainer with United Space Alliance, explaining the use of the slideware basket for emergency egress from the pad. Inside the basket are Pilot Jeffrey S. Ashby and Mission Specialist Michel Tognini of France, who represents the Centre National d´Etudes Spatiales CNES. The STS_93 crew members are at KSC to participate in a Terminal Countdown Demonstration Test, which familiarizes them with the mission, provides training in emergency exit from the orbiter and launch pad, and includes a launch_day dress rehearsal culminating with a simulated main engine cut_off. The primary mission of STS_93 is the release of the Chandra X_ray Observatory, which will allow scientists from around the world to obtain unprecedented X_ray images of exotic environments in space to help understand the structure and evolution of the universe. The targeted launch date for STS_93 is no earlier than July 20 at 12:36 a.m. EDT from Launch Pad 39B