NASA Administrator Daniel Goldin and First Lady Hillary Rodham Clinton are among the spectators at the Banana Creek viewing site to watch the launch of STS-93, the second attempt. Moments before the first scheduled launch, July 20, STS-93 was scrubbed at the T-7 second mark in the countdown due to an indication of a high concentration of hydrogen in an aft engine compartment. The reading proved to be a false alarm. The launch was rescheduled for July 22 at 12:28 a.m. Much attention has been generated over STS-93 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