A satellite constellation is a group of artificial satellites working together as a system. Unlike a single satellite, a constellation can provide permanent global or near-global coverage, such that at any time everywhere on Earth at least one satellite is visible. Satellites are typically placed in sets of complementary orbital planes and connect to globally distributed ground stations. They may also use inter-satellite communication.
A bright artificial satellite flare is visible above the Very Large Telescope. Satellite constellations could have an impact on ground-based astronomy.
A satellite or artificial satellite is an object in space, 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