UFO was created by Gerry Anderson, Sylvia Anderson and Reg Hill. and was produced by the Andersons and Lew Grade’s Century 21 Productions for Grade’s ITC Entertainment Company. It ran for one season of 26 episodes and was the Andersons’ first totally live-action TV series.
Unlike previous Anderson shows UFO was not aimed at children but was intended for an older audience; many episodes featured adult themes such as adultery, divorce, and drug use.
It took place in the near future – a fictional version of 1980 (a date indicated in the opening credits) – where Earth is being visited and attacked by aliens from a dying planet and humans are being covertly harvested for their organs by the aliens. The show’s main cast of characters are members of a secret, high-technology international agency called SHADO (an acronym for Supreme Headquarters, Alien Defence Organisation) established to defend Earth and humanity against the mysterious aliens and learn more about them, while at the same time keeping the threat of an alien invasion hidden from the public.
The alien race is never actually named, either by themselves or by human beings; they are simply referred to as “the aliens”. They are humanoid in appearance, and the autopsy of the first alien captured reveals that they are harvesting organs from the bodies of abducted humans. Their faces are stained green by the hue of a green oxygenated liquid, which is believed to cushion their lungs against the extreme acceleration of interstellar flight; this liquid is contained in their helmets. To protect their eyes the aliens wear opaque sclera contact lenses with small pinholes for vision. The show’s opening sequence begins by showing the image of one of these contact lenses being removed from an obviously real eye with a small suction cup, even though the lens is not shown in contact with the eye. (The entire lens-removal sequence is shown in the pilot episode.)
At no point in the series are more than two of the aliens seen on screen at any one time. Only two copies of the alien suit were constructed for the series. In the episode “Ordeal,” Paul Foster is carried by two aliens while he is wearing an alien space suit, but one of those two aliens is always off-screen when Foster is on-screen.