This event marks the launch of the Sputnik 36 satellite, a Soviet satellite launched in 1962. The satellite was the first of its kind to be sent into space, and its launch marked a major milestone in the history of space exploration. The satellite was designed to study the Earth's atmosphere
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.