A $300 device can silently override GPS across an entire city. Autonomous vehicles, delivery drones, and air traffic control all depend on it. Why don't we have a backup?

GPS jammers and spoofers are technically illegal in most countries. They're also sold openly online for under $300 and fit in a jacket pocket. A single one can override satellite signals across several miles. Commercial pilots have been quietly logging GPS failures over eastern europe and the middle east for years. Air traffic control still largely depends on the same signal your phone uses to find a coffee shop This wasn't a problem when GPS was just for navigation. It becomes a different kind of problem when autonomous vehicles, medical drones, and smart grid infrastructure all assume GPS is always there There's no widely deployed backup. eLoran, the terrestrial alternative, was largely dismantled in the 2000s because GPS seemed good enough. some countries are rebuilding it, most aren't. What happens to a city that's spent a decade building autonomous logistics around a signal anyone can disrupt for the cost of a dinner?