In this lecture, Mary Ellen Weber, Ph.D., will relate her experiences in space and as a NASA astronaut. After only two years in the astronaut corps, Dr. Weber was selected for her first space shuttle mission, aboard Discovery. In July 1995 the crew delivered to Earth orbit a critical communication satellite, and she was responsible for its checkout and launch. Throughout the nine-day mission, she also performed biotechnology experiments that grew human cancer tissues outside the body. In 2000, aboard Space Shuttle Atlantis, Dr. Weber took part in a critical early construction mission for the International Space Station, repairing and installing electrical and life-support equipment both inside and outside the station and boosting the station to a safe orbit. During the shuttle's rendezvous with the space station, she controlled the elaborate docking module and oversaw the final capture of the station. Dr. Weber says that while weightlessness is fun and fascinating, the technological and engineering aspects of the spacecraft themselves make flying in space even more spectacular. Successfully sending anyone into space is a mindboggling engineering feat, and the experience of spaceflight itself is incredible, she said.