This movie is about a rocket pilot named Pirx who is hired to go on a mission to evaluate some nonlinears (robots) for use as crewmembers on future space flights. Pirx and his crew, made up of nonlinears and humans, are sent out to launch two satellites into the rings of Saturn. Upon returning to Earth there is an inquest to determine if Pirx was responsible for the "accident." In the end, it is found that one of the robots caused the malfunction in an attempt to kill the human crewmembers and Pirx is cleared of all charges. In this tale Lem puts forth the idea that what is perceived a human weakness is in fact an advantage over a perfect machine. Pirx defeats the robot, because a human can hesitate, make wrong decisions, have doubts, but a robot cannot. A similar idea is present in Isaac Asimov's Robot Series, where putting a robot in a position where it cannot chose between the Three laws of robotics fries its positronic brain.