Commander Eileen Collins waves to spectators after landing at Kennedy Space.Center's Shuttle Landing Facility (SLF) aboard a T-38 jet aircraft, July 16, 1999 at Cape Canaveral, Florida. She and other crew members Pilot Jeffrey S. Ashby and Mission Specialists Steven A. Hawley (Ph.D.), Catherine G. "Cady" Coleman (Ph.D.) and Michel Tognini of France, with the Centre National d'Etudes Spatiales (CNES), are arriving for pre-launch activities. Collins is the first woman to serve as mission commander. This is her third Shuttle flight, set for July 20. The primary mission of STS-93 is the release of the Chandra X-ray Observatory, which.will allow scientists from around the world to study some of the most distant, powerful and dynamic objects in the universe.