One of the most ever-present devices in modern times is the navigation system in everything from cell phones and wrist watches to in-dash car displays. All of them are made possible with just a few constellations of satellites, most of them launched by the U.S.
But the systems use the satellite signals for free despite a cost in the billions to create and launch the satellites, and even as far back as 2012, $2 million was spent daily to maintain the U.S. system. So why are civilians across the world allowed to use them for free?
The big turning point was in 1983 when a Korean Air passenger jet flying near the Soviet border accidentally crossed into Russian territory in the Kamchatka Peninsula.
The Russians were worried that the plane was a U.S. bomber or spy plane, and made the catastrophic decision to attack the jet, downing it and killing all 269 passengers and crew members on board.
American officials later admitted privately that the error was an easy one to make and that the passenger jet was — probably accidentally — traveling on almost the exact same route that a U.S. spy plane was flying at the same time.
President Ronald Reagan publicly condemned the attacks and turned to his advisors to find a way to prevent other mix-ups in the future. He opened the GPS signals to public use with an executive order — but added scrambling to reduce accuracy.
This made the signals less valuable to rival militaries.
Civilian companies sprang up around GPS and worked to create devices that were perfectly accurate despite the scrambling. After almost a decade of the military increasing scrambling to foil technological workarounds, President Bill Clinton ordered that the scrambling come to an end.
Instead, the U.S. jams GPS signals locally when they're in combat with a force that uses them.
This jamming works by interrupting the signals, allowing the U.S. to scramble signals from its own satellites as well as those launched in more recent years by Russia, China, India, and Japan.