Aug 18, 2011 4:00 PM by Gene Cotton
SCHRIEVER AIR FORCE BASE, Colo. (AP) - A failing Global Positioning System satellite is being replaced with a spare satellite currently in orbit.
The Air Force said this week the satellite's clock began malfunctioning in May.
The backup satellite was switched on in June and functioned well. The Air Force says it will be tested over the next week before it is returned to active status.
The backup satellite was decommissioned in 2009 to make room for a newer model.
GPS uses 24 active satellites that beam signals to Earth. GPS receivers use the signals to calculate time, location and speed.
The satellites are controlled from Schriever Air Force Base, Colo., just east of Colorado Springs.
GPS is widely used in aviation, banking, weapons systems, civilian and military navigation and other functions.