France to test M51.3 ballistic missile from submarine Le Vigilant

France is preparing to launch an M51.3 intercontinental ballistic missile from the nuclear-powered submarine "Le Vigilant," marking the first such test in three years. The missile will be unarmed and is expected to travel approximately 4,700 kilometers. The launch follows extensive maintenance on the submarine, which began in autumn 2023 at Île Longue and included reactor and weapons system servicing. The test aims to confirm the strategic weapon system's functionality, with navigation restrictions in place off Finistère until October 21. The M51.3, which reached operational readiness in October 2025, offers improved range, accuracy, and penetration capabilities against missile defense. It can carry the new TNO-2 nuclear warhead and is intended for future SNLE 3G submarines replacing the Le Triomphant class after 2035.