Sputnik 3

Sputnik 3 (Спутник-3, Satellite 3) was a Soviet satellite launched on 15 May 1958 from Baikonur Cosmodrome by a modified R-7/SS-6 ICBM. The scientific satellite carried a large array of instruments for geophysical research of the upper atmosphere and near space. Sputnik 3 was the only Soviet satellite launched in 1958. Like its American counterpart, Vanguard 1, Sputnik 3 reached orbit during the International Geophysical Year. On 30 January 1956, the USSR Council of Ministers approved a project to launch an artificial Earth satellite using the R-7 rocket. Nicknamed "Object D", it would be the fifth type of payload built for the R-7 intercontinental ballistic missile, also known by its GURVO designation as 8K71. The original plan envisioned a sophisticated laboratory limited to 1,000 to 1,400 kg, of which 200 to 300 kg would be scientific instruments. It was intended to be launched during the International Geophysical Year as the first satellite by the Soviet Union but ended up being the third due to problems developing the extensive scientific experiments and their telemetry system. Despite earlier work done by Mikhail Tikhonravov, much of the satellite's design had little precedent. The creation and use of pressurized equipment, long-range communications systems, automated switches, and a metal construct to work in Earth orbit were all uncharted territories. By July 1956, OKB-1 had completed the preliminary design, but modifications to the R-7 for a satellite launch was ready before Object D could be finished. Worried at the prospect of the United States launching a satellite before he could, Sergei Korolev decided that the relatively simple "Prosteyshiy Sputnik-1" ("Simple Satellite 1", or PS-1), also known as Sputnik 1, would be the first satellite to be launched instead. Sputnik 2 (PS-2) was also ready and therefore launched earlier than Object D. Sputnik 3 was launched by a modified R-7 Semyorka missile developed for satellite launches, the Sputnik 8A91.