Season 7

This edition's contestants are given the challenge of building an igloo in the Scottish mountains. Each snow house is then judged by Heinz Wolff and his guest, mountaineer Myrtle Simpson (along with a few reindeer). Marks are awarded for habitability, architecture and decoration, among other things, in this 'eggloo race'. Since 1975, Heinz Wolff has held a number of honorary positions with the European Space Agency, including that of chairman of the Microgravity Advisory Committee. Indeed, his life-long medical research has focused on the application of technologies to help alleviate the problems of those whose environments have become hostile, including elderly and disabled people as well as space explorers.

Heinz Wolff hosts another episode of the quirky show, this time from Aviemore in Scotland, where contestants are assigned a canine task. Mountaineer Hamish MacInnes is the guest judge. In 1975, before working on 'The Great Egg Race', Heinz Wolff hosted 'The Royal Institution Christmas Lectures' for young people, which were televised by the BBC. As a member of the Medical Research Council, he gave six lectures on physiology and other topics connected with medicine, such as advancements in technology and research. These included the gamma camera, infra-red radiation and ultrasound, which were all new developments at the time.

Singer-songwriter Peter Skellern is the guest judge this week as the teams try to create a robotic pianist that is capable of playing a tune. Peter Skellern's 1972 hit 'You're a Lady' reached number three in the UK Top 40. He also worked on Radio 4's 'Stop the Week', for which he composed topical songs about that week's news.

The teams in this programme are given the task of constructing a remote-controlled mini-hovercraft using the contents of a garden shed. Which group of engineers will win? The guest judge is pioneer hovercraft engineer Ray Wheeler. An early concept for the hovercraft was evolved by British engineer Sir John Thornycroft in the 1870s. He looked into reducing a ship's drag by introducing a concave hull that allowed for air to pass between the craft and the water. The idea was developed further by Sir Christopher Cockerell, who invented the cross-Channel hovercraft, which first launched in 1959.