#7 GPS.
GPS is one of the most fantastic utilities ever devised by man. GPS will figure in history alongside the development of the sea-going chronometer. This device enabled seafarers to plot their course to an accuracy that greatly encouraged maritime activity. GPS will effect us all in so many ways. There are myriad applications, that will benefit us individually and collectively.
The global positioning system 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. The satellites are constantly moving, making two complete orbits around the Earth in just under 24 hours. If you do the math, that's about 2.6 kilometers per second. The GPS satellites are referred to as NAVSTAR satellites. Of course, no GPS introduction would be complete without learning the really neat stuff about the satellites too!The first GPS satellite was launched way back in February, 1978.