(06/22/1999) --- During launch and entry suit check in the Operations and Checkout Bldg, STS-93 Mission Specialist Michel Tognini of France, who represents the Centre National d'Etudes Spatiales (CNES), tries on his helmet. In preparation for their mission, the STS-93 crew are participating in Terminal Countdown Demonstration Test activities that also include equipment check and a launch-day dress rehearsal culminating with a simulated main engine cut-off. Others in the crew participating are Commander Eileen M. Collins, Pilot Jeffrey S. Ashby, and Mission Specialists Steven A. Hawley (Ph.D.) and Catherine G. Coleman (Ph.D.). Collins is the first woman to serve as a Shuttle commander. 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