A satellite navigation or satnav system is a system that uses satellites to provide autonomous geopositioning. A satellite navigation system with global coverage is termed global navigation satellite system (GNSS). As of 2023, five global systems are operational: the United States's Global Positioning System (GPS), Russia's Global Navigation Satellite System (GLONASS), India's Indian Regional Navigation Satellite System (IRNSS), China's BeiDou Navigation Satellite System (BDS), and the European Union's Galileo.
The U.S. Space Force's Global Positioning System was the first global satellite navigation system and the first to be provided as a free global service.
Launched GNSS satellites 1978 to 2014
A satellite or artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. Satellites have a variety of uses, including communication relay, weather forecasting, navigation (GPS), broadcasting, scientific research, and Earth observation. Additional military uses are reconnaissance, early warning, signals intelligence and, potentially, weapon delivery. Other satellites include the final rocket stages that place satellites in orbit and formerly useful satellites that later become defunct.
Two CubeSats orbiting around Earth after being deployed from the ISS Kibō module's Small Satellite Orbital Deployer
Replica of the Sputnik 1
Firing of Deep Space 1's ion thruster
The International Space Station's black solar panels on the left and white radiators on the right