Apollo 11, the first manned flight to the surface of the moon, was a spectacular feat. A major reason the flight was so successful was that Apollo 11 had already made the trip a great many times - theoretically in a computer. What a mess the first flights must have been! But, they were made without loss of astronauts, resources, or time. The technique used by NASA is available to, and being used by, managers and scientists in many fields.