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How are Navstar GPS satellites arranged in orbit around Earth?
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GPS
U.S. Navstar Global Positioning System (GPS) satellite in orbit over Earth, shown in an artist's conception.
The Navstar GPS constellation is arranged in six circular orbits around Earth. These satellites travel in single file within these orbital planes, which are inclined at 55° to the equatorial plane.12
At an altitude of approximately 12,500 miles (20,000 km), each satellite completes its orbit in 12 hours. This specific configuration ensures that at least five satellites are in view from most locations on Earth at any given time. While the core constellation consists of two dozen satellites, additional spares are maintained in orbit to ensure continuous, worldwide coverage.21