The R-36 (Russian: Р-36) is a family of intercontinental ballistic missiles (ICBMs) and space launch vehicles (Tsyklon) designed by the Soviet Union during the Cold War.

It was able to carry three warheads and was the first Soviet MIRV (multiple independently targetable re-entry vehicle) missile.

This missile was viewed by certain United States analysts as giving the Soviet Union first strike advantage over the U.S., particularly because of its rapid silo-reload ability, very heavy throw weight and extremely large number of re-entry vehicles.

[5] Some R-36 missiles have been converted into Dnepr medium-lift launch vehicles, capable of putting up to 4,500 kg into orbit.

Development of the R-36 was begun by OKB-586 (Yuzhnoye) in Dnepropetrovsk, Ukraine (at the time part of the Soviet Union) in 1962, and built upon the work of the R-16 program.

In 1970, development of a fourth version, capable of delivering multiple warheads, was begun, which was test flown the next year.

Further improvement of the R-36 led to the design of the R-36M, which provided a theoretical first-strike capability—the ability to destroy the United States' LGM-30 Minuteman ICBM silos and launch control centers before they could retaliate.

In the last decade[dubious – discuss] Russian armed forces have been steadily reducing the number of R-36M missiles in service, withdrawing those that age past their designed operational lifetime.

[10] In March 2006 Russia made an agreement with Ukraine that will regulate cooperation between the two countries on maintaining the R-36M2 missiles.

It was reported that the cooperation with Ukraine will allow Russia to extend the service life of the R-36M2 missiles by at least ten to 28 years.

[14] Missiles of the R-36M family have never been deployed with more than ten warheads, but given their large throw-weight (8.8 tonnes as specified in START), they have the capacity to carry considerably more detonation power.

The SALT II Treaty, signed in 1979, prohibited increasing the number of warheads ICBMs could carry.

To partially circumvent the treaty, the missile was equipped with 40 decoys to utilize the capacity left unused due to the 10-warhead limitation.

[17] The R-36 is a two-stage rocket powered by a liquid bipropellant, with UDMH as fuel and nitrogen tetroxide as an oxidizer.

[citation needed] The Tsyklon series of civilian space launchers from Ukraine is based on the R-36orb (8К69) or R-36-O (capital O for Orbital) design.

Variant of the R-36M carrying a single large reentry vehicle, with a warhead yield of 18-25 Mt, a distance of about 11,000 kilometres (6,000 nmi).

The testing phase of the R-36M with various different types of warheads was finished in October 1975 and on 30 December 1975 deployment began (though some Western sources suggest that an initial operational capability was reached in early 1975).

These high-yield weapons were assessed in the West as possibly developed to attack American Minuteman ICBM launch control centers.

The MIRVs were placed in pairs, and a post boost vehicle with a command structure and a propulsion system were contained in the nose cone of the R-36M.

According to some Western estimates, evidence suggested that it may be capable of carrying as many as 14 RVs (this may reflect observation of the deployment of countermeasures intended to overcome a ballistic missile defense, or to confuse American attack characterization systems).

[citation needed] This newer, more accurate version placed in converted silos allowed the R-36M family to remain the bulwark of the SRF's hard-target-kill capability.

The engine of the second stage is completely built into the fuel tank (earlier this was only used on SLBMs) and the design of the transport-launching canister was altered.

The drum-like "piston" is filled with a slow-burning, gas pressure-generating charge that pushes, mortar-like, the missile from the container.

This feature was a deep concern for the US side during the SALT/START negotiations, as it gave Soviet Union the possibility to strike US targets again after the first missile exchange was concluded.

[citation needed] The flight tests of the R-36M2 missile carrying a single warhead with a yield of 20 Mt were completed in September 1989 and deployment began in August 1991.