The Global Positioning System, commonly referred to as GPS, is the most significant recent advancement in Earth navigation. It uses a network of 24 to 27 Earth orbiting satellites, transmitting precise microwave signals to Earth. This system permits space identification of any location on Earth and navigation from one location to another. The GPS provides direction to a destination, and also provides distance and speed.
The GPS satellite on exhibit is a thermal test specimen and is the only one on display in the world. It is just one of the many types of satellites orbiting the Earth today. The solar panels, such as the ones seen on the GPS, are one way to provide the power needed to function. Satellites can also carry their power internally, sometimes using a nuclear power supply.
Other unmanned objects have been launched from Earth on a variety of missions, including exploring the furthest reaches of our solar system. Most of them stay in Earth orbit, and are used for weather observation, monitoring climate change, observing changes in land use and severe weather warnings. The larger picture, seen from hundreds of miles above, reveals more than ground observations, or even low altitude aerial views. The military use of satellites allows observation of other nations from the relative safety of orbit.
Satellites have especially revolutionized communications. Global news events can be watched in real time anywhere in the world and phone calls can be easily routed to any city in the world.