For those unfamiliar he fronted a brilliant show in the late 70s and early 80s called The Great Egg Race - the first two seasons involved building machines to carry an egg using the power of a standardised rubber band either as far as possible, or as fast as possible over a set distance. Subsequent runs involved challenges similar to Scrapheap Challenge (Junkyard Wars as it was known in the US) and probably spawned both those shows and Robot Wars. He was also involved with space research and made some milestone breakthroughs in haematology.
He was a truly interesting character and I have fond memories of watching him on TV.