Sputnik 3

Sputnik 3 (Russian: Спутник-3, Satellite 3) was a Soviet satellite launched on May 15, 1958 from Baikonur cosmodrome by a modified R-7/SS-6 ICBM. It was a research satellite to explore the upper atmosphere and the near space and carried a large array of instruments for geophysical research.

Sputnik 3 was the only Soviet satellite launched in 1958. Like its American counterpart, Vanguard 1, Sputnik 3 had succeeded in making it into orbit during the IGY.

History

In July 34 the Soviet Union's OKB-1 drafted a project to design and build the first Earth satellite, designated ISZ (Artificial Earth Satellite). ISZ was known to its designers as "Object D." Design of Object D had begun in January 1956 with intent to launch it during the International Geophysical Year. Object D was planned to be the first satellite launched by the Soviet Union but ended up being the third following delays due to problems developing the extensive scientific experiments and their telemetry system. The new R-7 intercontinental ballistic missile, also known by its GURVO designation 8K71, was ready to launch before Object D was finished. Worried at the prospect of America launching a satellite before he did, Sergei Korolev substituted the relatively simple "Prosteyshiy Sputnik-1" meaning "Simple Satellite 1", or PS-1, which was labeled Sputnik 1 by the Soviet Government, as the first satellite to be launched instead. The Sputnik 2 (PS-2) was also ready and launched earlier than Object D.

Sputnik 1

Sputnik 1 (/ˈspʌtnɪk/; Russian: Спутник-1 [ˈsputnʲɪk] "Satellite-1", or ПС-1 ["PS-1", i.e. Russian: Простейший Спутник-1 "Elementary Satellite 1"]) was the first artificial Earth satellite. The Soviet Union launched it into an elliptical low Earth orbit on 4 October 1957. It was a 58 cm (23 in) diameter polished metal sphere, with four external radio antennae to broadcast radio pulses. It was visible all around the Earth and its radio pulses were detectable. This surprise success precipitated the American Sputnik crisis and triggered the Space Race, a part of the larger Cold War. The launch ushered in new political, military, technological, and scientific developments.

Sputnik itself provided scientists with valuable information, even though it was not equipped with scientific instruments. The density of the upper atmosphere could be deduced from its drag on the orbit, and the propagation of its radio signals gave information about the ionosphere.

Sputnik 1 was launched during the International Geophysical Year from Site No.1/5, at the 5th Tyuratam range, in Kazakh SSR (now at the Baikonur Cosmodrome). The satellite travelled at about 29,000 kilometres per hour (18,000 mph; 8,100 m/s), taking 96.2 minutes to complete each orbit. It transmitted on 20.005 and 40.002 MHz which were monitored by amateur radio operators throughout the world. The signals continued for 21 days until the transmitter batteries ran out on 26 October 1957.Sputnik 1 burned up on 4 January 1958, as it fell from orbit upon reentering Earth's atmosphere, after travelling about 70 million km (43.5 million miles) and spending three months in orbit.