Developed in the early 1970s, the R-36M became the largest ballistic missile ever deployed by the Soviet strategic forces. Known in the West as SS-18 Satan, the missile remained in armaments of the Russian military at the turn of the 21st century. However, with the end of the Cold War, a fearsome weapon turned into a space launcher, carrying commercial payloads into orbit.
In 1968, as the nuclear arms race between the US and the USSR continued unabated, the KB Yuzhnoe ("Southern") design bureau in Dnepropetrovsk, Ukraine, proposed a major modernization of the existing R-36 missile system.
The main goal of the modernization program was to introduce so-called Multiple Independently Targetable Reentry Vehicles, MIRVs. At the time, the MIRV technology emerged as the latest breakthrough in the delivery systems for nuclear weapons. However, the development of the MIRV warhead presented a formidable engineering problem for the Soviet rocket scientists.
In order to steer each individual warhead toward its target, developers were proposing guidance systems of unprecedented complexity. One concept called for the use of a "digital portrait" of the target stored in the onboard computer of the missile.
Mikhail Yangel, the head of KB Yuzhnoe, was the first to convince Nikolai Pilugin, the head of a major Soviet development center for rocket guidance technology, to develop a flight control system for a new upper stage, which could carry multiple warheads toward their targets.
At the time, KB Yuzhnoe competed with Vladimir Chelomei's design bureau for the orders of a new generation of the intercontinental ballistic missiles by the Soviet strategic forces. Vladimir Chelomei proposed relatively simple and cheap upgraded versions of the already deployed UR-100 missile, which he believed could address emerging threats in the Cold War. The Soviet Defense Council presided over by Leonid Brezhnev had to evaluate alternative proposals from both organizations and approve mass production of particular systems.
Eventually, the Defense Council ordered vehicles from both organizations, further burdening already strained Soviet economy. (27)
On September 2, 1969, Council of Ministers of the USSR issued a resolution, approving the development and manufacturing of the R-36M missile, setting its first flight test for 1971.
General overview of 15PO14 system
According to final specifications formulated by KB Yuzhnoe in 1969, the R-36M was to have following features:
All this upgrades promised to extend the operational life of the system and increase its survivability under conditions of the nuclear war. Developers estimated that the R-36M program yielded performance upgrades, comparing to the previous generation of R-36 missiles in following areas:
Traditionally, for previous missiles developed at KB Yuzhnoe in Dnepropetrovsk, the propulsion system designers at KB Energomash in Khimki near Moscow proposed a cluster of six engines for the first stage of the R-36M missile. A single engine of the same design, but with extended (high-altitude) nozzle could be employed on the second stage. However, Mikhail Yangel, the head of KB Yuzhnoe broke the old partnership, turning to KBKhA design bureau based in Voronezh for the propulsion system. Yangel cited KB Energomash's overload with the development of the engines for the UR-700 rocket as a reason to seek a new engine supplier.
The first stage of the R-36M missile was powered by a cluster of four RD-263 engines, collectively known as RD-264. All four engines could be gimbaled up to seven degrees from longitudinal axis of the vehicle to steer the rocket in flight. The engine had a trust of 100 tons and the pressure inside of the combustion chamber of 200 atmospheres. (113)
The second stage was powered by a single main engine and a four-chamber steering engine.
The propulsion system development
Also in 1969, the KB Energomash design center in Khimki, near Moscow completed a preliminary design of the RD-264 engine, which would power the first stage of the R-36M rocket.
In April 1970, KB Energomash for the first time test-fired the main element of the R-36M propulsion system -- the RD-263 engine. A cluster of four such engines would comprise the RD-264. During 1971, Energomash started shipping documentation for the RD-263 to KB Yuzhnoe in Dnepropetrovsk, where the engine would be mass-produced. (167)
Between December 1972 and January 1973, KB Energomash test-fired a first series of RD-263 engines at its facility in Khimki, near Moscow. The engines were manufactured at Yuzhnoe production plant in Dnepropetrovsk and were intended for the flight version of the R-36M missile. In September 1972, the engines were officially certified for flight. (113)
Designated 15F143U, the warhead section of the R-36M missile featured its own propulsion system and could carry three different types of reentry vehicles, RVs. A multi-warhead version of the warhead carried a cluster of ten reentry vehicles in two configurations.
Each reentry vehicle carrying nuclear charge was equipped with its own solid-propellant engine developed at NPO Altai and designated 15D161 and 15D221.
The R-36M was also designed to carry a single warhead designated 15F141, apparently the most destructive warhead in the Soviet arsenal.
In all configurations, the missile carried an assortment of dummy warheads, along with live charges. Both, live and dummy warheads, were equipped with their own solid-propellant motors.
The launch facility 15P714
The R-36M missiles were designed to be deployed in modified and heavily reinforced OS-67 silos, which were originally built for then retiring R-36 missiles. (98) A special suspension system was proposed for the R-36M's launch canister, allowing to "recycle" available silos for the new missile. However, E. G. Rudyak, chief-designer of the KBSM design bureau in Leningrad (now St. Petersburg), a chief developer of missile silos, insisted on traditional design of the silo for the R-36M. The traditional approach would require custom-built silos for the new missile.
As a result, in August 1969, Mikhail Yangel, the head of the R-36M program, charged the KBTM design bureau in Moscow with the task of studying ways of modifying and hardening old silos for the R-36M missiles. The organization had to complete the preliminary design of the facility in the fourth quarter of 1969.
The project reportedly put considerable stress on the KBTM bureau, which lacked resources and experience in designing such structures. (114) Yet, in 1970, Department 8 (PKO-8) of KBTM started preliminary work on the launch complex for the R-36M missile. The project was considered so urgent that the work was conducted seven days a week. The team developed a number of techniques allowing to harden the existing silos and designed a suspension system for the launch canister. At the same time, the problems of engine exhaust inside the silo remained unresolved, until Mikhail Yangel proposed "cold launch" concept for the R-36M missile.
The "cold launch" concept
Upon its final assembly at its manufacturing plant in Dnepropetrovsk, the R-36M would be encapsulated into a canister made from reinforced fiberglass and designated 15Ya53. The container isolated the missile from the environment, thus extending its operational life.
The "cold launch" system, first implemented in the R-36M missile, was designed to eject the rocket from the silo with the help of a special Powder Pressure Generator, or PAD. The main propulsion system of the missile would then ignite in midair. Installed in the silo, the PAD generator was capable of sending a 210-ton vehicle up to 20 meters into the air, where the missile's engine would come alive. The "cold launch" technique allowed the deployment of missiles in smaller and cheaper silos without complex exhaust deflection systems required for the R-36 missiles, which fired its engines inside the silo. (86)
The PAD generator for the R-36M missile was developed in cooperation between KB Yuzhnoe and LNPO Soyuz in the town of Lubertsy near Moscow.
The pressurized gas generated by the PAD would push a special cap, which shielded the tail section of the missile. After leaving the silo, the cap would separate from the missile with special springs and three powder motors would then push it away.
According to the official data, the R-36M missile standing in the battlefield readiness could be launched within 62 seconds after the command to fire.
The "cold launch" concept development
After initial consideration, the "cold launch" concept was accepted for further evaluation at KBTM, with the goal of amending the preliminary design of the launch system for the R-36M missile by the first quarter of 1970. In May 1970, KBTM successfully defended the amended preliminary design of the launch system taking advantage of the "cold launch" concept at the Scientific-Technical Council of the MOM, the ministry overseeing the rocket industry.
Actual test launches of the R-36M missile were preceded by the so-called "throw trials," aimed to validate the "cold launch" concept. The first "throw trials" designated BI-1 (Broskovye Ispytaniya-1) started on the grounds of Pavlograd Mechanical Plant, Ukraine, in January 1970. (74) The tests then moved to Site 67 at the NIIP-5 range under designation BI-2.
In the course of the BI-2 tests, the prototype of the missile would be filled with water instead of propellant and the pressure generator would send the vehicle 20 meters up into the air above the silo. The protective cap at the bottom of the missile would then separate and the vehicle would crash into the special concrete bed near the silo. The first such experiment took place on October 22, 1971. (168)
During the BI-3 "throw trials," initiated on March 6, 1972, the missile actually fired its first stage engines after ejection from the silo and then flew some short distance.
The first test launch of the R-36M missile took place on February 21, 1973. In May of the same year, KB Energomash conducted random testing of the RD-263 engines from the first production batch delivered by the Yuzhnoe plant from Dnepropetrovsk. The testing of the RD-263 concluded with "interagency certification firings," MVI, of four engines in September 1973. As a result of the previous tests, the engines featured an improved ignition system. (167)
Total 43 launches of the R-36M missile took place, with 36 of them classified as successful. One of the failed launches of the R-36M missile took place in December 1974, due to a failure of the engine on the first stage. (113)
On December 30, 1975, the Central Committee of the Communist Party, CPSU, and the Council of Ministers signed a resolution ordering the operational deployment of R-36M and MR-UR-100 missiles. (23)
Additional test launches of the R-36M missile carrying "light" 15B86 warhead continued until April 1976. The warhead was formally adopted into armaments in 1978.
Between July 1978 and August 1980, the R-36M had also flown a number of test missions with a 15F678 self-guided warhead. It was designed to use digital "radio-brightness" and elevation maps to guide itself to the target. This type of warhead had never been adopted into armaments. At the end of these tests, the R-36M logged 95 launches. (98)
2004 June 29: Russian Strategic Missile Forces, RVSN, test-fired an R-36M missile from the Baikonur Cosmodrome. The flight aimed to certify the service life of such systems for a 20-year period.
The R-36M missile with a single warhead emerges from its silo during a test launch in Baikonur. Credit: KB Yuzhnoe
Yuri Smetanin, one of the developers of the R-36M missile, poses with a scale model of the rocket. Credit: KB Yuzhnoe
A dynamic test model of the R-36M missile with a single warhead section. Copyright © 2001 by Anatoly Zak
The RD-264 propulsion system for the first stage of the R-36M missile consisted of four RD-263 engines. Credit: KB Yuzhnoe