This event marks the launch of the Sputnik 17 satellite on April 12, 1962. This satellite was the first of its kind to be sent into space by the Soviet Union, and it marked a major milestone in the space race between the United States and the Soviet Union. The satellite was
From Wikipedia
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.