In the 1940s, when the newly minted Jet Propulsion Laboratory needed quick-thinking mathematicians, it recruited an elite group of young women -- known as human computers -- who, with only pencil, paper, and brain power, helped bring about America's first ballistic missiles. But their hearts lay in the dream of space exploration, and when JPL became part of NASA, the computers helped send the first probes to the moon. 337 pages.