NASA responds to John F. Kennedy's challenge of landing a man on the moon with a group of new astronauts for the Gemini Program, who work toward the eventual lunar voyage with a series of risky and groundbreaking earth-orbit missions.

America's first man in space, Alan Shepard, is grounded with an inner ear disorder. A thankless new desk job starts to look permanent, until fate—and surgery—bring him a chance to rescue the space program.