M51: a new generation of missile
The M51 is the new generation of French strategic submarine-launched ballistic missiles, designed to keep pace with changing threats and defences. It entered service at the end of 2010. As for all the ballistic missile systems in France nuclear deterrence force, Airbus Defence and Space is prime contractor for their development, production, deployment and maintenance services on behalf of the French defence procurement agency (DGA) for the French Navy.
The M51 is significantly different to the M45, its currently operational predecessor, in terms of shape, size, weight and even its interface with the submarine launch tubes. It features multiple warheads, with far greater payload mass and volume (including warheads and penetration aids). It also offers longer range than the M4, enabling submarines to expand their patrol zones. Weighing a total of 50 tonnes (compared to 35 for the M4 missiles) each of its three stages is powered by a solid rocket motor equipped with a flex-bearing nozzle. The first and second stage structures are made of wound carbon-epoxy fibre. Five first test flights of the missile successfully took place in 2006, 2007, 2008 and 2010.
The nuclear submarine Le Terrible has been equipped with the M51 since late 2010. The missile will also enter operational service on board the other new-generation submarines of the French Strategic Oceanic Force Vigilant, Triomphant and Téméraire, after retrofit. A second version, the missile upper stage with new nuclear warheads, will be commissioned from 2015.