4 October 1957 was a major milestone in aerospace history, marking the first launch of an artificial satellite into Earth orbit. Since 1955, a relatively low-key “space race” between the U.S. and the Soviet Union had been underway, with the U.S. openly developing the small Vanguard booster rocket and satellite and planning to launch the first satellite into orbit during the International Geophysical Year (1 July 1957 to 31 December 1958). Secrecy surrounding the Soviet Union’s space program made the successful launch of Sputnik 1 a significant political coup, which served to greatly energized the lagging U.S. space program and prompted calls for more technical education in the U.S.
The small spherical Sputnik 1 satellite had a diameter of 23 inches (58 cm) and a weight of 184 pounds (83.6 kg). Functionally, Sputnik 1 was very simple, consisting of a battery power supply, a radio transmitter, a thermal control system and a remote control switch housed within the nitrogen-pressurized sphere. You’ll find a description of how Sputnik 1 worked at the following link:
The satellite transmitted a continuous “beep-beep-beep…” until 28 October 1957, when it went silent.
Sputnik was launched by an R-7 liquid-fueled booster rocket, which was a version of the Soviet Union’s first intercontinental ballistic missile (ICBM). The R-7 booster rocket was developed by the design bureau headed by Sergei Pavlovitch Korolev (1906-1966). That booster evolved into the launch vehicle for future Soviet Vostok and Voskhod projects, and a version continues in use today as the Russian launch vehicle taking astronauts and supplies to the International Space Station (ISS).
Sputnik 1’s low Earth orbit decayed over the next three months and the satellite reentered the Earth’s atmosphere and was destroyed on 4 January 1959, after about 1,400 orbits. Sputnik 1 had a lasting effect on the space race between the U.S. and the Soviet Union.