The R-36 () is a family of intercontinental ballistic missiles (ICBMs) and space launch vehicles (Tsyklon) designed by the Soviet Union during the Cold War. The original R-36 was deployed under the GRAU index 8K67 and was given the NATO reporting name SS-9 Scarp. It was able to carry three warheads and was the first Soviet MRV (multiple re-entry vehicle) missile. The later version, the R-36M was produced under the GRAU designations 15A14 and 15A18 and was given the NATO reporting name SS-18 Satan. 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. Some versions of the R-36M were deployed with 10 warheads and up to 40 penetration aids and the missile's high throw-weight made it theoretically capable of carrying more warheads or penetration aids. Contemporary U.S. missiles, such as the Minuteman III, carried up to three warheads at most. The R-36 became the base for the Tsyklon launch vehicles family. As of early 2021, Cyclone-4M, the last Tsyklon variant in development, is planned for launch in 2023 from Canso, Nova Scotia. Some R-36 missiles have been converted into Dnepr medium-lift launch vehicles, capable of putting up to 4,500 kg into orbit. History 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. The Chief Designer was Mikhail Yangel. Initial development was of light, heavy, and orbital versions, with flight testing from 1962 through 1966, at which time initial operational capability was achieved. News of the development of the orbital version caused alarm in the West with the possibility that the Soviets would be able to launch a large number of nuclear weapons into orbit where there was no capability to intercept them. Weapons could potentially be left orbiting for an indefinite period. The prospect of orbital nuclear weapons led both sides to agree to a treaty banning the basing of weapons of mass destruction in space. 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