Sputnik 1 (Russian: "Спутник-1" Russian pronunciation: [ˈsputnʲɪk], "Satellite-1", or literally "Co-pather-1" byname ПС-1 (PS-1, i.e. "Простейший Спутник-1", or Elementary Satellite-1)) was the first artificial satellite to be put into outer space. Launche into geocentric orbit by the Soviet Union on 4 October 1957, it was the first of a series of satellites collectively known as the Sputnik program.