First Lady Hillary Rodham Clinton and her daughter, Chelsea, are greeted by NASA Administrator Daniel S. Goldin upon their arrival at the Skid Strip at Cape Canaveral Air Station. Next to Gold are (from left) Deputy Director for Business Operations Jim Jennings and Mrs. Goldin. Mrs. Clinton and Chelsea are here to view the launch of Space Shuttle mission STS-93, scheduled for 12:36 a.m. EDT July 20. Much attention has been generated over the launch due to Commander Eileen M. Collins, the first woman to serve as commander of a Shuttle mission. The primary payload of the five-day mission is 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. The new telescope is 20 to 50 times more sensitive than any previous X-ray telescope and is expected to unlock the secrets of supernovae, quasars and black holes