How do you make a spaceman? You start the same way that you start to make a chess master, a ballet dancer, a trapeze performer, or any other difficult and complex task demanding highly trained and concentrated skills, physical or mental; you start when the future professionals are too young to know whether that is what they want out of life, or not. United Nations Expeditionary Planetary Survey—UNEPS—starts every year with one hundred five-year-olds, discovered, in early testing, to be both mentally and physically superior. Twelve years later the best graduates of the Academy are given a Ship and sent out to find habitable planets for humans to live on. But what happens to a small crew of teenagers once the Ship leaves Earth?