Space launch
Launch of Sputnik 1
October 4, 1957
On 4 October 1957 the Soviet Union placed Sputnik 1, the first artificial Earth satellite, into an elliptical low Earth orbit. It transmitted a radio signal back to Earth for three weeks until its three silver-zinc batteries ran flat. Aerodynamic drag brought it back into the atmosphere on 4 January 1958, by which time it had already set off the Space Race.