As World War II ends, German rocket expert Dieter Kolff (Michael York) forms an alliance with American engineer Stanley Mott (Bruce Dern). Meanwhile, Navy officer Norman Grant (James Garner) emerges a war hero, inspiring John Pope (Harry Hamlin) to enlist for duty.

Pope's girlfriend Penny Hardesty (Blair Brown) volunteers to help Grant win a senatorial seat, while Mott and Kolff's rocket experimentation intensifies. Kolff reunites with his lover Liesl (Barbara Sukowa).

During flight training, Pope develops a close relationship with Marine officer Randy Claggett (Beau Bridges). The neglected Elinor Grant (Susan Anspach) becomes the pawn of Leopold Strabismus (David Dukes), while her senator husband drifts into an affair with Pope's wife, Penny.

Pope and Claggett begin training for America's manned-flight program, as ambitious young journalist Cindy Rhee (Maggie Han) researches a behind-the-scenes story resulting in an affair with the married Claggett.

With America's first astronauts becoming media celebrities, Claggett tries to repair John and Penny's broken marriage as he and Pope prepare for a dangerous voyage to the dark side of the moon.