The 24 satellite network that makes up the satellite-based Global Positioning System (GPS) is placed into orbit by the U.S. Department of Defence. Although this technology was primarily created for military use, it was made available for civilian usage in 1980 by the government. This method works 365 days a year in any setting, anywhere in the world. The 24 satellites that make up the GPS rotate once every 12 hours, providing global time, location, and velocity data. By calculating the distance from the satellites, GPS's primary purpose is to precisely locate places on the world.