The top 60s pop group Cliff Richard and the Shadows "appear" in this film in puppet form, Portrayed as future versions of themselves. They perform two songs: "Lady Penelope", an instrumental, and "Shooting Star", accompanying Cliff Richard
The first feature film to be shot using the Livingston Electronic Viewfinder Unit, also known as Add-a-Vision. This was basically an electronic viewfinder that could be used in conjunction with a Mitchell BNC Camera to take a television picture directly from the camera, enabling the staff of the entire unit to watch any scene being filmed on the television monitors.
Jeff calculates that as it is 11am on Tracy Island, it is 4pm in England and, indeed, Lady Penelope is just sitting down to tea. Unless the world's time zones have changed by 2067, this puts Tracy Island somewhere just off the coast of Chile or Peru.
Because Panavision cameras couldn't cope with special effects (at the time), a scope camera was still needed for filming, so Techniscope was used instead. This would also be used in the filming of Thunderbird 6 (1968).
During International Rescue's mission to save Zero X's crew, Brains travels as a passenger on Thunderbird 1. This is one of only two occasions where a passenger has flown in Thunderbird 1; the first time was when Scott took Tony and Bob Williams to Tracy Island in the Thunderbirds episode "Cry Wolf".