This event marked the launch of the Sputnik 18 satellite in 1962, a major milestone in the space race between the United States and the Soviet Union. The satellite was the first of its kind to be sent into space, and its launch marked the start of a new era of space exploration
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.