GPS, as awesome as it is, shouldn't be considered the ultimate navigational tool. Like any technology, it has its weaknesses, especially when it comes to "electrical activity in the upper atmospheric zone called the ionosphere," which can tamper with signals from GPS satellites.
Organizations such as the American Meteorological Society have held meetings explaining to companies reliant on GPS that it's not foolproof, and that "space weather," sci-fi as it sounds, exists.
Lockheed Martin built the GPSIIIA and has received milestone approval and permission to build and deploy. The GPSIIIA promises to cut through pesky space weather.
There's a correlation here: by placing more of our faith-and our lives-in the hands of GPS, the more bandwidth we're stealing from common sense. And common sense, after all, is a unique characteristic of human beings-so why would we let that go?