Some of the best and most up-to-date communication satellites in the world are designed and built in Stevenage in Britain. With exclusive access to specialist manufacturer Astrium, this programme shows step-by-step how to assemble one of the most complicated machines.

They are constantly circling hundreds of miles above our heads, driving our daily lives - yet we barely give satellites a second thought.

Documentary celebrating the 50th anniversary of the first satellite, Sputnik, which launched the space age in 1957. The film explores how satellites have affected almost every aspect of our lives, from spy satellites and GPS transforming the military to the communications revolution kickstarted by Telstar. But recent events in China have revealed just how vulnerable we might be, for they suggest we might be on the verge of another new age, one of satellite terrorism.