Sylvia Anderson first episode of a series then sharing the work according to their strengths. Gerry tended to specialise in special effects and hardware, and Sylvia in character, voices, costume, dialogue, and plotlines. In this way, Anderson contributed plot development and voice work for a series of half-hour shows including "Supercar", "Stingray" and "Fireball XL5". However, she felt the half-hour format was insufficient to fully develop characters and stories, and she persuaded the team's TV producer Lew Grade to extend their shows to a full hour. In the early 1960s, the Andersons co-created the series "Thunderbirds", and Sylvia created the characters. She
UFO (TV series) positions, so the occasional disappearance of characters—some of whom would later return in other positions—fits in with the concept of the series. Also, owing to the scheduling of the series not reflecting the production order, some episodes featuring departed cast members were not broadcast until late in the series, which can give the impression that no major cast changes occurred. Only Ed Bishop appeared in every episode. One of the female Moonbase operatives, Joanna, was played by Shakira Baksh, who later married actor Michael Caine. Producer Gerry Anderson later said that he had lost his temper with her so badly