The M51 is a French long-range, solid-fueled, MIRV-capable, submarine-launched ballistic missile. It is a core component of France’s nuclear deterrent force.

M51 Development

Originally, France had planned to replace the M45 with the M5, but in 1996 the Ministry of Defense decided the cost of the program was not justified and reduced its capabilities.¹ The M51 was subsequently developed, and deployed in 2010. The M51 is the sixth missile in France’s MSBS (Mer-Sol-Balistique-Stratégique) family, following the M1, M2, M20, M4, and M45.

The missile has considerably greater range than its predecessor, the M45, as well as improved accuracy and performance capabilities – including penetration aids capable of matching the abilities of the Russian anti-ballistic missile system.²

M51 Specifications

The missile is 13.0 m long, 2.35 m in diameter, and weighs 53,000 kg. The estimated range of the missile is 8,000 km. The M51.1 carries between four and six MIRVs using the TN-75 warheads developed for the M45 missile. Each RV has a total weight of 230 kg while holding a 115 kg warhead. Each MIRV has a nuclear yield of 150 kT. The M51.2 version will carry upgraded Tête Nucléaire Océanique (TNO) nuclear warheads with yields up to 150 kT in a new RV, weighing 500 kg.³

M51 Service History

The missile entered development in 1998, with its first flight in 2004. Subsequent flight tests were made in November 2006, June 2007, January 2010, and July 2010.⁴ In 2010, the first batch of missiles to replace the M45 SLBM were deployed on SSBN Le Terrible, the last of four SNLE-NG (Sous-Marins Nucléaires Lanceurs Engins-Nouvelle Génération) new generation submarines. Eventually, all four SNLE-NG submarines, Le Triomphant, Le Temeraire, Le Vigilant, and Le Terrible, will carry 16 missiles each.⁵

Although 57 missiles were originally planned for production, when the French government decided to reduce its total number of missiles to below 300, it is probable that the actual number of missiles produced was reduced as well.⁶

After two successful flight tests made in 2010 from Le Terrible, the 51.1 variant was declared operational in September. The 51.2 version is believed to have been tested in 2012 and is scheduled to become operational in 2015.⁷

On May 6, 2013, an M51 SLBM failed in testing when the missile malfunctioned and self-destructed.⁸