This is a film about an unusual scientific adventure, which had the ultimate goal of establishing the ability to control gravity. For centuries the greatest scientific minds have struggled with the precise workings of gravity, from Newton to Faraday and Einstein, to them the concept of controlling gravity has been seen as little more than a fanciful dream.

However in the mid 1990’s the British defence manufacturer BAE Systems began working on a ground-breaking project code-named Greenglow. Simultaneously on the other side of the Atlantic the American space agency NASA was also running its own Breakthrough Propulsion Physics Project. Both projects set out to make science fiction a reality and included research into concepts such as ‘faster-than-light travel’ and ‘warp drives’.

In this BBC special Horizon explores science’s long-standing obsession with the idea of gravity control. We are taken on a journey in search of loopholes in conventional physics and examine how the groundwork carried out by these projects have helped change our understanding of the universe.