THE GLOBAL POSITIONING System has to be one of the most successful investments the US has ever made, and not just because GPS-enabled map apps on mobile phones have saved the directionally challenged like me from perpetually getting lost. GPS also powers thousands of critical services that we take for granted today, like routing cell phone calls, sending electricity to our homes, and enabling us to get cash from an ATM. Even stock exchange trades now rely on GPS.1 It’s not much of an exaggeration to say we couldn’t function as a modern society without it.
