France: First submarine launch of the M51.3 ballistic missile, fired by Le Vigilant off Brittany

The French nuclear-powered ballistic missile submarine (SNLE) Le Vigilant fired an M51.3 strategic ballistic missile, without a nuclear warhead, off Finistère in Brittany on Tuesday, October 6, the French Armed Forces Ministry announced. It is the first time the newest version of the missile on which the sea-based leg of France’s nuclear deterrent rests has been fired from a submarine.

According to the ministry, the launch took place under Operation SMERTRIOS, to confirm that the submarine can use the M51 after its periodic maintenance and repair stoppage (IPER). The missile was tracked throughout its flight by assets of the Directorate General of Armaments’ missile testing service (DGA Essais de missiles), including the test and measurement ship Monge. The impact zone is in the North Atlantic, “several hundred kilometres from any coast”. The launch was carried out “without a nuclear payload and in strict compliance with France’s international commitments”, the statement says.

President Emmanuel Macron watched the launch from a French Navy frigate, the Élysée and the ministry announced jointly. “On board the multi-mission frigate Auvergne, I attended the first firing of the new M51.3 ballistic missile from the nuclear-powered ballistic missile submarine Le Vigilant. Very few nations have such know-how,” Macron wrote in a post on X, adding his congratulations to everyone involved in the success.

What the M51.3 is

The M51.3 is the third version of the M51 submarine-launched strategic ballistic missile and entered operational service in October 2025. It carries the new TNO-2 nuclear warheads and, according to the French ministry, outperforms earlier versions in range, accuracy and penetration capability. According to the statement, the M51.3 “ensures in the long term the reliability of the oceanic component in the face of the evolution of the adversary’s anti-missile defences”. The M51, an intercontinental-range missile with multiple warheads and a mass of about 54 tonnes, has served in the French Strategic Oceanic Force (FOST) since 2010, while work on the third version began in 2014, according to the DGA.

The first launch of the M51.3 took place on November 18, 2023, but from land: it was a qualification firing from the DGA Essais de missiles facilities in the Landes region. France has four SNLE submarines, of the Le Triomphant class. Since August 28, 2025, the DGA has already commissioned ArianeGroup to develop and produce the next version, the M51.4. It is expected to enter service within the next decade and will equip both the current submarines and the third-generation SNLEs, which have been in development since 2021.