Artificial Satellite

An artificial satellite is an object, typically a spacecraft, deliberately placed into orbit around a celestial body, used for purposes including communication relay, weather forecasting, navigation, broadcasting, scientific research and Earth observation. The idea was explored in fiction well before it was realized, notably in Edward Everett Hale's 1869 short story The Brick Moon, and the Russian scientist Konstantin Tsiolkovsky's 1903 treatise Exploring Space Using Jet Propulsion Devices was the first academic study of using rocketry to place an object in orbit. The Soviet Union launched the first actual artificial satellite, Sputnik 1, into Earth orbit on October 4, 1957, opening the Space Age and leading within a generation to the thousands of communication, navigation, scientific and Earth-observation satellites now in orbit.