Sputnik 1 becomes the first artificial satellite to orbit the Earth.
Sputnik 1, often referred to as simply Sputnik, was the first artificial Earth satellite. It was launched into an elliptical low Earth orbit by the Soviet Union on 4 October 1957 as part of the Soviet space program. It sent a radio signal back to Earth for three weeks before its three silver-zinc batteries became depleted.
Aerodynamic drag caused it to fall back into the atmosphere on 4 January 1958.
Watch: Sputnik 1 - Documentary
From the studioworks photography channel.
Sources and further reading: Wikipedia — Sputnik 1 (CC BY-SA). Images: Wikimedia Commons.
