M51 (missile)

M51 SLBM
Type	SLBM
Service history
In service	27 September 2010
Production history
Manufacturer	EADS Astrium Space Transportation
Unit cost	4 billion euro for the programme
Specifications
Weight	52,000 kg
Length	12.0 m
Diameter	2.3 m
Warhead	M51.1 = 6 to 10 TN 75 MIRV 107 kiloton (kt) (420 TJ), with penetration aids. M51.2 (2015) = using the new Tête nucléaire océanique 150 kt / CEP 150-200 m
Engine	three stage Solid-fuel rocket (Ammonium perchlorate composite propellant)
Operational range	8,000-10,000 km
Speed	Mach 25
Guidance system	Astro-inertial guidance. Galileo (satellite navigation) system is planned.
Launch platform	Triomphant class submarines

The M51 SLBM is a submarine-launched ballistic missile, built by Airbus Defence & Space, and deployed with the French Navy. Designed to replace the M45 SLBM (In French terminology the MSBS - Mer-Sol-Balistique-Stratégique “Sea-ground-Strategic ballistic”), it was first deployed in 2010.

Each missile carries six to ten independently targetable TN 75 thermonuclear warheads.

The three-stage engine of the M51 is directly derived from the solid propellant boosters of Ariane 5.

The missiles are a compromise over the M5 SLBM design, which was to have a range of 11,000 km (6,800 mi) and carry 10 new generation Tête nucléaire océanique' (“Oceanic nuclear warhead”) MIRVs. Design work on the M5 started in 1992, before the programme was renamed the M51 in 1996, when development costs decreased by 20 percent. The M51 entered service in 2010.

Development

After having spent €5 billion ($6.7 billion) developing the missile, the French government placed a €3 billion ($3.9 billion) order with EADS SPACE Transportation for the M51 in December 2004. The contract covered serial production of the M51 for 10 years, with the company to be responsible for sustained readiness support throughout the missile's life.

The M51 performed its first flight test (unarmed) on 9 November 2006 from the French missile flight test centre in Biscarrosse (Landes). The target was reached twenty minutes later, in the north-west of the Atlantic Ocean.

A second and third successful test were carried out on 21 June 2007 and 13 November 2008.

On 27 January 2010, at 9h25, a missile was launched underwater by Le Terrible, from Audierne Bay. The missile reached its target 2,000 kilometres off South Carolina; the 4,500 kilometre flight took less than 20 minutes.

The 10 July 2010 test validated the Triomphant class submarine's capacity to launch the M51 in operational conditions.

On 5 May 2013, an M51 flight test missile failed after being fired by a submerged SSBN off the coast of Brittany. This was the first failed launch of the M51 after 5 successful launches since 2006.

On 30 September 2015, a M51 was successfully test-flown from a land-based missile site near Biscarrosse to a desolate target in the North Atlantic.

Operators

France

French Navy is the only operator of the missile.

Sources and references

• nrdc.org: Table of French Nuclear Forces, 2002
• globalsecurity.org M-5 / M-51
• M51 Gives France More Flexible Deterrent To Meet Changing Threats, Aviation Week

Comparison of different nuclear systems: left, the SNLE (Redoutable type) with the M4 missile; right, the SNLE-NG (Triomphant type) with the previous M45 missile and the current M51 missile.