GPS first became an operational system around 1990. That's when it's experiment status was changed to functional. Bill Clinton ordered SA turned off. Even WAAS is a few years old.

Now everyone is using it to navigate, including the airlines - instead of flying from one radio beacon to the next they can fly a direct course, saving millions on fuel.

I believe the newest generation satellites are the same system with stronger transmitters. GPS in it's present implementation will be around for a very very, long time.

Think of all the drivers screaming to their congressmen if the government turned off their street navigators.

The best insurance against GPS failure is to have a few spares. I have four working aboard, including one in a steel box in case of lightening strike.