Sapwood SS-6 8K71PS

R-7A
A 2-view drawing of the R-7 Semyorka (NATO code-name SS-6 Sapwood)
Type	Ballistic missile
Place of origin	Soviet Union
Service history
In service	9 February 1959 - 1968
Used by	USSR: Strategic Missile Troops
Wars	Cold War
Production history
Designer	Sergei Korolev
Designed	From 1953
Manufacturer	OKB-1
Specifications
Weight	280 metric tons (280 long tons; 310 short tons)
Length	34 m (112 ft)
Diameter	3.02 m (9.9 ft)
Engine	1st stage: 4x jettisonable four-chamber RD-107 booster engines each with 2x vernier rocket engines plus 1x four-chamber RD-108 core engine with 4x vernier rocket engines. 2nd stage: 1x four-chamber RD-108 core engine with 4x vernier rocket engines. RD-107 4x 907.4 kN (203,992 lbf) RD-108 1x 907.4 kN (203,992 lbf) Vernier 12x 38.259 kN (8,601 lbf)
Propellant	LOX/T-1
Guidance system	Inertial guidance with radio control of vernier thrusters for launch.
Steering system	12x vernier thrusters arranged around the booster clusters and the core engines
Accuracy	2.5-5.0 kilometers (max. deviation 10 kilometers)

The R-7 (Russian: Р-7 "Семёрка") was a Soviet missile developed during the Cold War, and the world's first intercontinental ballistic missile. The R-7 made 28 launches between 1957 and 1961, but was never deployed operationally. A derivative, the R-7A, was deployed from 1959 to 1968. To the West it was known by the NATO reporting name SS-6 Sapwood and within the Soviet Union by the GRAU index 8K71. In modified form, it launched Sputnik 1, the first artificial satellite, into orbit, and became the basis for the R-7 family which includes Sputnik, Luna, Molniya, Vostok, and Voskhod space launchers, as well as later Soyuz variants.

The widely used nickname for the R-7 launcher, "Semyorka", means "the 7" in Russian.

The R-7 was 34 m (112 ft) long, 3.02 m (9.9 ft) in diameter and weighed 280 metric tons (280 long tons; 310 short tons); it had two stages, powered by rocket engines using liquid oxygen (LOX) and kerosene and capable of delivering its payload up to 8,800 km (5,500 mi), with an accuracy (CEP) of around 5 km (3.1 mi). A single thermonuclear warhead was carried with a nominal yield of 3 megatons of TNT. The initial launch was boosted by four strap-on liquid rocket boosters making up the first stage, with a central 'sustainer' motor powering through both the first and the second stage. Each strap-on booster included two vernier thrusters and the core stage included four. The guidance system was inertial with radio control of the vernier thrusters.