On October 28, France’s Directorate General of Armament (DGA) marked a new milestone by announcing the operational entry into service of the new M51.3 ballistic missile, developed and produced by ArianeGroup. After a decade of research and testing, the system was declared fully operational to equip the Le Triomphant-class nuclear-powered ballistic missile submarines of the French Navy, thus strengthening the European nation’s ocean-based nuclear deterrent amid an increasingly unstable geopolitical environment.
According to official information, the missile entered service on October 24, completing a process that began in 2014 under the supervision of the DGA and the Atomic Energy Commission (CEA). This new version of the M51 constitutes the fifth generation of French ballistic missiles, whose first series was introduced in 2010, and represents the culmination of a modernization cycle aimed at maintaining France’s strategic capability beyond 2040.
It is worth noting that the M51 is the most modern submarine-launched ballistic missile in service with the French Armed Forces. With its introduction, the French Navy seeks to replace the M45 missiles that have been in service since the 1990s, first deployed in 1996 with the nation’s Submarine Forces as the main means of nuclear deterrence.
During its development, the M51.3 successfully passed a qualification flight in November 2023 from the Ballistic Launch Base (BLB) at the DGA Essais de Missiles test center in Biscarrosse, validating the performance of its new guidance, propulsion, and reinforced structural systems. Over the following two years, efforts focused on verifying its operational performance and compliance with nuclear safety standards through integration campaigns and onboard testing aboard the Le Triomphant-class strategic ballistic missile submarines (SSBNs).
The M51.3 version features a three-stage solid-fuel motor derived from its predecessor, but with a new set of propellants and navigation electronics that improve its range and accuracy. It is also equipped with the TNO-2 nuclear warhead, developed by the CEA under France’s nuclear simulation program. “This operational deployment marks the culmination of the M51.3 and TNO-2 programs, respectively led by the DGA and the CEA, ensuring the continuity of our capabilities for this strategic mission,” stated the Ministry of the Armed Forces in an official release.
In technical terms, the M51.3 maintains similar dimensions to its predecessors: 12 meters in length, 2.3 meters in diameter, and a weight of approximately 52 tons, with an estimated range between 8,000 and 10,000 kilometers and a maximum speed of Mach 25. Its modernization will ensure the continuity of France’s ocean-based nuclear deterrence for the next two decades, as work already advances on its successor, the M51.4. The design and production phase for this next-generation missile was awarded to ArianeGroup in September 2025, with testing expected to begin in the next decade.
Photographs and images used for illustrative purposes.
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