Global Positioning System (GPS) is the only fully functional global navigation system in town and utilizes a “constellation” of 24 medium Earth orbit communications satellites that broadcast precise radio-frequency signals back to the Earth. GPS has become much more than a simple navigational tool, and is firmly embedded in the technology fabric of planet Earth. Many weapon systems use GPS to track potential ground and air targets before they are flagged as hostile and destroyed. GPS survey equipment has revolutionized plate tectonics by directly measuring the motion of faults in earthquakes. The earliest origins of GPS can be traced to similar ground-based radio navigation systems that were developed by the allied forces during World War II. On February 10, 1993, the National Aeronautic Association selected the entire GPS team as winner of the 1992 Robert J. Collier Trophy, the most prestigious aviation award in the United States.