R-11 Zemlya
Encyclopedia
The R-11 Zemlya,, GRAU index 8A61 was a Soviet
Soviet Union
The Soviet Union , officially the Union of Soviet Socialist Republics , was a constitutionally socialist state that existed in Eurasia between 1922 and 1991....

 tactical ballistic missile
Tactical ballistic missile
A tactical ballistic missile is a ballistic missile designed for short-range battlefield use. Typically, range is less than . Tactical ballistic missiles are usually mobile to ensure survivability and quick deployment, as well as carrying a variety of warheads to target enemy facilities, assembly...

. It is also known by its NATO reporting name SS-1 Scud-A. It was the first of several similar Soviet missiles to be given the reporting name Scud
Scud
Scud is a series of tactical ballistic missiles developed by the Soviet Union during the Cold War, and exported widely to other countries. The term comes from the NATO reporting name SS-1 Scud which was attached to the missile by Western intelligence agencies...

.

The R-11 originated from a 1951 requirement for a ballistic missile with similar performance to the German V-2 rocket, but half its size. With the Wasserfall
Wasserfall
The Wasserfall Ferngelenkte Flakrakete , was a World War II guided surface-to-air missile developed at Peenemünde, Germany.-Technical characteristics:...

, an anti-aircraft version of the V-2, as a model the R-11 was developed by engineer Victor Makeev
Victor Makeev
Viktor Petrovich Makeyev was the founder of the Soviet-Russian school of sea missiles production.-Work:Makeyev's work has resulted in three generations of submarine-launched ballistic missiles being used by the Russian Navy.Among these were:...

, who was then working in OKB-1, headed by Sergey Korolyov
Sergey Korolyov
Sergei Pavlovich Korolev ; died 14 January 1966 in Moscow, Russia) was the lead Soviet rocket engineer and spacecraft designer in the Space Race between the United States and the Soviet Union during the 1950s and 1960s...

. The two men disagreed over the propulsion of the missile, with Korolev favouring the use of liquid oxygen
Liquid oxygen
Liquid oxygen — abbreviated LOx, LOX or Lox in the aerospace, submarine and gas industries — is one of the physical forms of elemental oxygen.-Physical properties:...

, while Makeev advocated the use of toxic, but storable fuel. Makeev's version, that first flew on 18 April 1953, was fitted with an Isayev
Aleksei Mihailovich Isaev
Aleksei Mikhailovich Isaev was a Russian rocket engineer.Aleksei Isaev began work under Leonid Dushkin during World War II, on an experimental rocket-powered interceptor plane. In 1944 he formed his own design bureau to engineer liquid-propellant engines...

 engine using RP-1
RP-1
RP-1 is a highly refined form of kerosene outwardly similar to jet fuel, used as a rocket fuel. Although having a lower specific impulse than liquid hydrogen , RP-1 is cheaper, can be stored at room temperature, is far less of an explosive hazard and is far denser...

 and nitric acid
Nitric acid
Nitric acid , also known as aqua fortis and spirit of nitre, is a highly corrosive and toxic strong acid.Colorless when pure, older samples tend to acquire a yellow cast due to the accumulation of oxides of nitrogen. If the solution contains more than 86% nitric acid, it is referred to as fuming...

 as a propellant. On 13 December 1953, a production order was passed with SKB-385 in Zlatoust
Zlatoust
Zlatoust is a city in Chelyabinsk Oblast, Russia, located on the Ay River , west of Chelyabinsk. Population: 181,000 ; 161,000 ; 99,000 ; 48,000 ; 21,000 ....

, a factory dedicated to producing long-range rockets. In June 1955, Makeev was appointed chief designer of the SKB-385 to oversee the programme and, in July, the R-11 was formally accepted into military service. The definitive R-11M, designed to carry a nuclear warhead, was accepted officially into service on 1 April 1958. The launch system received the GRAU
Grau
Grau is a German word meaning "gray" and a Catalan word meaning "grade". It may refer to:* BAP Almirante Grau , a De Zeven Provinciën class cruiser in service with the Peruvian Navy* Grau Käse, Tyrolean grey cheese...

 index 8K11.

Like the V-2, the R-11 relied on inertial guidance
Inertial navigation system
An inertial navigation system is a navigation aid that uses a computer, motion sensors and rotation sensors to continuously calculate via dead reckoning the position, orientation, and velocity of a moving object without the need for external references...

, and its flight was controlled by four graphite
Graphite
The mineral graphite is one of the allotropes of carbon. It was named by Abraham Gottlob Werner in 1789 from the Ancient Greek γράφω , "to draw/write", for its use in pencils, where it is commonly called lead . Unlike diamond , graphite is an electrical conductor, a semimetal...

 vanes in the engine exhaust, that were active only while the motor was burning. The R-11M had a maximum range of 270 kilometres, but when carrying a nuclear warhead, this was reduced to 150 kilometres. At maximum range, it was found to have an average range error 1.19 kilometres and an azimuth error of 0.66 kilometres. It was used as a mobile nuclear strike vector, giving the Soviet Army
Soviet Army
The Soviet Army is the name given to the main part of the Armed Forces of the Soviet Union between 1946 and 1992. Previously, it had been known as the Red Army. Informally, Армия referred to all the MOD armed forces, except, in some cases, the Soviet Navy.This article covers the Soviet Ground...

 the ability to hit European targets from forward areas. To give the system sufficient mobility on the battlefield, the R-11 was mounted on the chassis of an IS-2 tank
Iosif Stalin tank
The Iosif Stalin tank , was a heavy tank developed by the Soviet Union during World War II and first used in the Kursk area in September 1943...

, that became its first transporter erector launcher
Transporter erector launcher
A transporter erector launcher is a vehicle with an integrated prime mover that can carry, elevate to firing position and launch one or more missiles. Such vehicles exist for both surface-to-air missiles and surface-to-surface missiles...

. The only payload was a nuclear warhead with an estimated yield of 50 kilotons.

A naval variant, the R-11FM (SS-N-1 Scud-A) was first tested at Kapustin Yar
Kapustin Yar
Kapustin Yar is a Russian rocket launch and development site in Astrakhan Oblast, between Volgograd and Astrakhan. Known today as Znamensk , it was established 13 May 1946 and in the beginning used technology, material, and scientific support from defeated Germany...

 in February 1955, and was first launched from a converted Project 611 (Zulu class) submarine in September of the same year. While the initial design was done by Korolev's OKB-1, the programme was transferred to Makeev's SKB-385 in August 1955. It became operational in 1959 as the D-1 launch system, the world's first submarine-launched ballistic missile
Submarine-launched ballistic missile
A submarine-launched ballistic missile is a ballistic missile capable of delivering a nuclear warhead that can be launched from submarines. Modern variants usually deliver multiple independently targetable reentry vehicles each of which carries a warhead and allows a single launched missile to...

 (SLBM), and was deployed onboard Project 611 and Project 629 (Golf Class) submarines, until its replacement by the R-13 in 1961 (SS-N-4) and the R-21 (SS-N-5) in 1963. During its service, 77 launches were conducted, of which 59 were successful. The success of the R-11FM established Makeev as the main designer of submarine-launched weapons for the Soviet military.
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