By Greg Milner
In the cool, dark hours after midnight on June 20, 2012, Todd Humphreys made the final preparations for his attack on the Global Positioning System. He stood alone in the middle of White Sands Missile Range, in southern New Mexico, sixty miles north of JuΓ‘rez. All around him were the glowing gypsum dunes of the Chihuahuan Desert. In the distance, the snow-capped San Andres Mountains loomed.
On a hill about a kilometre away, his team was gathered around a flat metal box the size of a carry-on suitcase. The electronic machinery inside the box was called a spoofer—a weapon by another name. Soon, a Hornet Mini, a drone-operated helicopter popular with law-enforcement and rescue agencies, was scheduled to appear forty feet above them. Then the spoofer would be put to the test.
Humphreys, an engineering professor at the University of Texas at Austin, had been working on this spoofing technology for years, but he was nervous. Witnessing the test that morning was a group of about fifteen officials from the Federal Aviation Administration, the Department of Homeland Security, and the Air Force’s 746th Test Squadron. They were Humphreys’s hosts, but they very much wanted him to fail. His success would mean a major reckoning for the entire G.P.S. system—and, in turn, for the effectiveness of some of the country’s principal military and defense systems. Drones, which rely on G.P.S. to navigate, are an increasingly indispensable part of our security apparatus. Demand for them is growing elsewhere, too. There are now over a million more recreational drones in the sky than there were just four years ago. Sales of high-precision commercial-grade drones—for everything from pipeline inspections to 3-D mapping—increased more than five hundred per cent during the same period.
















