Thunderbirds Are Go is a 1966 British science-fiction film based on Thunderbirds, a 1960s television series starringmarionette puppets and featuring scale model effects in a filming process dubbed "Supermarionation". Written by Thunderbirdscreators Gerry and Sylvia Anderson, directed by David Lane and produced by AP Films, Thunderbirds Are Go develops the franchise with a plot focusing on the futuristic spacecraft Zero-X and its manned mission to Mars. When Zero-X suffers a mechanical failure during re-entry, it is up to International Rescue, with the aid of the Thunderbird machines, to save the astronauts on board before the spacecraft is obliterated in a crash landing.
Filmed from March to June 1966 and premiering in December, Thunderbirds Are Go includes, in a first for an AP Films production, cameo appearances from puppets of real-life celebrities Cliff Richard and The Shadows, who also contributed to the musical score. It is also the first motion picture to have been filmed with an early form of video assist technology known as "Add-a-Vision", and incorporated landscape footage that was shot on location in Portugal. Special effects pieces, produced under the supervision of Derek Meddings and including rocket launch sequences, space shots and a miniature representation of the Martian surface, required six months to complete.
Despite positive initial reviews, which praised the film as a well-made cinematic transfer of the Thunderbirds television series, Thunderbirds Are Go soon proved to be a box office failure for the Andersons. The disappointment of this outcome was intensified by the knowledge that Series Two of Thunderbirds would be cut down to six episodes and that AP Films' upcoming television project would be a brand-new series, which would later be titled Captain Scarlet and the Mysteronsand screened from 1967. To add to the lukewarm public response, negative critical reception of Thunderbirds Are Go has targeted, besides other aspects, the characterisation of the puppet cast, the running time dedicated to model and effects shots, and the fantasy dream sequence starring Cliff Richard and The Shadows, which has been described as a poor scriptwriting idea on the part of the Andersons.
Surprised by the underperformance of Thunderbirds Are Go, the United Artists distributors authorised the production of a sequel. However, Thunderbird 6 received a similarly unenthusiastic response on its release in 1968, and theThunderbirds franchise was abandoned until the appearance of a reboot, starring live actors, in 2004. Meanwhile, the Zero-Xastronauts were featured in their own strip in the Anderson-related TV Century 21 comic until 1969.