Stock markets, war, your trip to the country: we rely on the Global Positioning System for an awful lot these days. Yet the entire network is controlled by eight men and women who − in every sense − carry the world on their shoulders. At 23 years old, Joshua Williams seems a little young to be in charge of the Global Positioning System. Three years ago, it was still illegal for him to buy a drink. Two years before that, he was back home in Virginia learning to drive. And yet today he’s responsible for a constellation of 35 satellites, each one of them worth upwards of £40million and vital for the safe passage of billions of people, in cars, ships and aeroplanes all over the world. Read More