gsfprez writes "It took us a long time, but the Air Force has finally moved off of the 1970's mainframe GPS control system and is now running on a new Unix-based Control System called AEP — Architecture Evolution Plan. It's important to remember that current GPS satellites are basically solar powered iPod shuffles with atomic clocks that simply playback whatever we upload into them at a precise rate. They don't actually have any idea where they are — its the control system at Schriever Air Force Base that does. The new system will be a lot cheaper to support and modify since Sun stocks things like SATA drives - while digging up Saturday Night Fever-era DASDs isn't simple. AEP will also allow us to be ahead of the curve: we're basically good to go to fly the new IIF birds."