When President Kennedy issued his well-known challenge to reach the moon and return safely before the end of the 1960s, the immediate responsibility for undertaking the task fell to 54-year-old NASA director James E. Webb. Eight years later, when the Apollo II spacecraft splashed down safely in the Pacific and the screens in NASA's Mission Control at Houston flashed the words "Task Accomplished", it was Webb who deserved much of the credit. In powering...