Interplanetary pirating provides the twist here. Cadet Peter Hodges is washed out of space academy due to an old collar bone injury. From the thin thread of this disappointment and its aftermath in his irritability, and a dishonorable discharge for picking a fight he didn't pick, he falls into a den of thieves who blackmail him into helping them spike the rockets. Before he gets his just desserts-there are sundry events like the Interplanetary Fair, the acquisition of a space suit in the nick of time, and so forth. More sentiment than science.