The global positioning system (GPS) is a satellite-based navigation system consisting of a network of 24 orbiting satellites that are eleven thousand nautical miles in space and in six different orbital paths. This system is designed and constructed by the government of the United States for the military use primarily. The satellites are constantly moving, making two complete orbits around the Earth in just under 24 hours., that's about 1.8 miles per second. To know GPS, you should know the history of the story from the very beginning: - The first GPS satellite was launched back in February, 1978. - Each satellite weighs approximately 2,000 pounds and is about 17 feet across with the solar panels extended. - Transmitter power is only 50 watts, or less! - Each satellite transmits two signals, L1 and L2. Civilian GPS uses the 'L1' frequency of 1575.42 MHz. - Each satellite is expected to last approximately 10 years. Replacements are constantly being built and launched into orbit. The GPS
		program is currently funded with replacements through 2006.
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