A communication satellite is one of the most complicated machines in the world to assemble. It has to operate for a minimum of 15 years in space, and so precision is everything.

The fuel tanks help to fire the satellite into orbit, but this requires some highly toxic fuel and an explosive test to check the tanks can handle the pressure of the trip into space.

Find out more in How to Build... A Satellite, which will be broadcast on Sunday 27 November at 20:00 GMT on BBC Two.