More than 30 years on, sci-fi series UFO is still a winner

Whirling silver spaceships from a cult sci-fi show have proved a money-spinner 30 years on. The series UFO has generated £6m in the past three years, with nostalgia lovers shelling out on spin-offs from the show .

Much of the cash from the show - made by the Thunderbirds creator Gerry Anderson - has come from its DVD release. In the live-action series, first aired in 1970, Earth was under constant attack from UFOs, with Shado (Supreme Headquarters Alien Defence Organisation) trying to fend them off. More than 40,000 DVDs have been sold in the UK in a year.

UFO has been shown in more than 70 countries in recent years. It is hugely popular in Japan whereUFO figurines and model kits have gone on sale, as well as a new CD on which various Japanese bands play 83 different versions of its theme tune.