The M20 was a French

submarine-launched ballistic missile A submarine-launched ballistic missile (SLBM) is a ballistic missile capable of being launched from submarines. Modern variants usually deliver multiple independently targetable reentry vehicles (MIRVs), each of which carries a nuclear warhead ...

(SLBM) deployed on the nuclear s from 1977. It was withdrawn from service by 1991.

History

The M20 was the third member of the MSBS (''Mer-Sol-Balistique-Stratégique'', "sea-ground ballistic strategic") family which comprised a number of submarine-launched, intermediate range missiles. The force constitutes the second leg of the French nuclear deterrent force. The M1 version went into service in 1971 and was phased out in favour of the M2 in 1974, itself replaced by the M20 in 1977. The new M4 missile entered service in 1985 and has replaced the M-20. French nuclear-powered submarines (

SNLE A ballistic missile submarine is a submarine capable of deploying submarine-launched ballistic missiles (SLBMs) with nuclear warheads. The United States Navy's hull classification symbols for ballistic missile submarines are SSB and SSBN � ...

: ''Sous-marin Nucléaire Lanceur d'Engins'', "Nuclear Device-Launching Submarine"), are able to carry 16 missiles each. The oldest ship, ''Redoutable'', was not converted to carry the M-4 and was withdrawn from service in 1991. Logistical support for the MSBS fleet is provided by the Île Longue Naval Base in Brest Bay, where the assembly and storage facilities for maintenance of readiness are located. Three SSBNs are intended to be operational at any one time. The M20 system entered service in 1977. There were 100 missiles produced, and the M20 ceased operational deployment in 1991.

Technical

The M-20 was a two-stage, solid propellant,

intermediate-range ballistic missile An intermediate-range ballistic missile (IRBM) is a ballistic missile with a range of 3,000–5,500 km (1,864–3,418 miles), between a medium-range ballistic missile (MRBM) and an intercontinental ballistic missile (ICBM). Classifying ...

, 10.4 m in length and 1.5 m in diameter. Launch weight was 20,000 kg and the missile had a range of 3,000 km. Control of the first stage was by four

gimbal A gimbal is a pivoted support that permits rotation of an object about an axis. A set of three gimbals, one mounted on the other with orthogonal pivot axes, may be used to allow an object mounted on the innermost gimbal to remain independent of ...

led

nozzle A nozzle is a device designed to control the direction or characteristics of a fluid flow (specially to increase velocity) as it exits (or enters) an enclosed chamber or pipe. A nozzle is often a pipe or tube of varying cross sectional area, ...

s; the second stage by thrust vector control through a single fixed nozzle. The first stage propellant weighed 10,000 kg and burned for 55 seconds, the second stage propellant weighed 6,015 kg and burned for 58 seconds. Guidance was

inertial In classical physics and special relativity, an inertial frame of reference (also called inertial reference frame, inertial frame, inertial space, or Galilean reference frame) is a frame of reference that is not undergoing any acceleration. ...

. The payload was believed to include some penetration aids and the single re-entry vehicle had some hardening against nuclear effects. The TN-60 warhead was reported to yield 1.2 Mt.

Operators

; *

French Navy The French Navy (french: Marine nationale, lit=National Navy), informally , is the maritime arm of the French Armed Forces and one of the five military service branches of France. It is among the largest and most powerful naval forces in th ...

References

External links

* George C. Marshall and Claremont Institutes
French SLBM
Submarine-launched ballistic missiles of France Nuclear weapons of France Projects established in 1977 1977 in military history 1970s in France 1970 establishments in France 1991 disestablishments in France Military equipment introduced in the 1970s {{Missile-stub