A planet is discovered in the same orbit as Earth's but is located on the exact opposite side of the sun, making it not visible from Earth. The European Space Exploration Council decide to send American astronaut Glenn Ross and British scientist John Kane via spaceship to explore the other planet.
| Directing | Robert Parrish | Director |
| Production | Sylvia Anderson | Producer |
| Writing | Sylvia Anderson | Screenplay |
| Writing | Sylvia Anderson | Story |
| Editing | Len Walter | Editor |
| Production | Gerry Anderson | Producer |
| Writing | Gerry Anderson | Screenplay |
| Writing | Gerry Anderson | Story |
| Production | Brian Burgess | Production Manager |
| Camera | John Read | Director of Photography |
| Art | Bob Bell | Art Direction |
| Sound | Barry Gray | Original Music Composer |
| Production | Ernest Holding | Associate Producer |
| Visual Effects | Derek Meddings | Visual Effects Director |
| Art | Philip Bawcombe | Assistant Art Director |
| Costume & Make-Up | Geoffrey Rodway | Makeup Artist |
| Costume & Make-Up | Barbara Ritchie | Hairstylist |
| Directing | John O'Connor | Assistant Director |
| Art | Chris Burke | Assistant Art Director |
| Editing | Margaret Miller | Assistant Editor |
| Camera | Godfrey A. Godar | Camera Operator |
| Sound | John Peverill | Sound Editor |
| Production | Ivo Nightingale | Location Manager |
| Costume & Make-Up | Gloria Barnes | Wardrobe Master |
| Costume & Make-Up | Elsa Fennell | Wardrobe Supervisor |
| Sound | Ken Rawkins | Sound Recordist |
| Directing | Joan Davis | Continuity |
| Production | Julie Leighton-White | Production Secretary |
| Sound | Ted Karnon | Sound Recordist |
| Writing | Donald James | Screenplay |
