| M51 SLBM | |
|---|---|
| Type | SLBM |
| Service history | |
| In service | 27 September 2010 |
| Production history | |
| Designer | ArianeGroup |
| Manufacturer | ArianeGroup |
| Specifications | |
| Mass | 52,000 kg (115,000 lb) |
| Length | 12.0 m (39 ft 4 in) |
| Diameter | 2.3 m (7 ft 7 in) |
| Warhead | M51.1 = 6 to 10TN 75 MIRV 110 kiloton (kt) (420 TJ), with penetration aids. M51.2 (2015) = using the newTête nucléaire océanique 100 kt / CEP 150–200 m[1][2] |
| Engine | three-stagesolid-fuel rocket (ammonium perchlorate composite propellant) |
Operational range | Estimated 8,000–10,000 km (4,300–5,400 nmi; 5,000–6,200 mi)[3][4] (the range is classified information) |
| Maximum speed | Mach 25[3][4] |
Guidance system | Astro-inertial guidance.Galileo system is planned. |
Launch platform |
|
TheM51 SLBM is a Frenchsubmarine-launched ballistic missile, built byArianeGroup, and deployed with theFrench Navy. Designed to replace theM45 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 tenindependently targetableTN 75thermonuclear warheads.
The three-stage engine of the M51 is directly derived from the solid propellant boosters ofAriane 5. Like other blunt-nosed SLBM examples, such as theTrident D5, the M51 uses anextensible aerospike in the nose.
The missiles are a compromise over theM5 SLBM design, which was to have a range of 11,000 km (6,800 mi) and carry ten new-generationtête nucléaire océanique ("oceanic nuclear warhead") MIRVs. Design work on the M5 started in the late 1980s byAérospatiale,[5] before the programme was renamed the M51 in 1996, when development costs decreased by 20 percent.[6] The M51 entered service in 2010.[7]
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 ten years, with the company to be responsible for sustained readiness support throughout the missile's life.[8][9]
In 2014 Airbus signed a deal with the French government for development work on an upgrade designated M51.3 to equip the new ballistic missile submarines of the French Navy,SNLE 3G. On 10 May 2016 Airbus and Safran signed a joint joint partnership to develop the M51.3 upgrade intended to enter service around 2025.[10]
M51.4: On August 28, 2025, the French Armaments Agency (DGA) awarded ArianeGroup the contract for the development and production of the fourth version (M51.4) of the M51 strategic ballistic missile.[11]
The M51 performed its first flight test (unarmed) on 9 November 2006 from the French missileflight test centre inBiscarrosse (Landes). The target was reached twenty minutes later, in the north-west of the Atlantic Ocean.[12] A second and third successful test were carried out on 21 June 2007[13] and 13 November 2008.[14]
On 27 January 2010, at 9h25, a missile was launched underwater by theFrench submarine Le Terrible, fromAudierne Bay off the coast ofBrittany in north-western France.[15] The missile reached its target 2,000 kilometres (1,100 nmi) offSouth Carolina; the 4,500-kilometre (2,400 nmi) flight took less than 20 minutes.[16][17] A 10 July 2010 test validated theTriomphant-class submarine's capacity to launch the M51 in operational conditions.[18]
On 5 May 2013, an M51 flight test missile failed after being fired by a submerged ballistic missile submarine off the coast of Brittany. This was the first failed launch of the M51 after five successful launches since 2006.[19] On 30 September 2015, an M51 was successfully test-flown from a land-based missile site near Biscarrosse to a desolate target in the North Atlantic.[20]
On 12 June 2020, a successful test launch of a M51 missile was conducted from theTriomphant-class submarineLe Téméraire off the south-west tip ofFinistère, Brittany.[21] On 28 April 2021, the FrenchMinistry of Armed Forces announced that it had tested an M51 missile. The test was not launched from a French NavyTriomphant-class submarine but from a land-based facility located in southwestern France.[22] On 19 April 2023, Ministry of Armed Forces announced another M51 test launched fromLe Terrible.[23]
An M51.3 was test fired successfully in November 2023.[24] It entered operational service in late 2025 with a reported operational range of 8,000 to 10,000 km, a speed of Mach 25 and improved accuracy and penetration capabilities. In September 2025, ArianeGroup was awarded a contract to design and produce the fourth version of the M51 submarine launched ballistic missile (SLBM) known as “M51.4”.[25]
