From AOPA web site:
New GPS satellite ensures future of system
When a new GPS satellite was launched on Sunday, some AOPA members wondered what it means for general aviation. The answer: GPS navigation will be around for a long time to come.
The new satellite replaces an aging bird that's nearing the end of its useful life, ensuring that the GPS signal will continue to be available even as some older satellites are taken off line.
"The latest launch represents a firm commitment to satellite navigation and demonstrates that there will be plenty of assets in space to ensure that the GPS signal is always available," said Randy Kenagy, AOPA senior director of advanced technology. "That's especially important for general aviation as more GPS-based wide area augmentation system (WAAS) approaches are created." WAAS approaches allow for ILS-like minima without the expensive ground-based equipment.
There are already several "hot spare" satellites on orbit should a GPS signal fail, and GPS availability is not a concern at this time.
The Air Force expects to launch an average of three new GPS satellites each year to replace older equipment.
September 29, 2005