The M51 SLBM is the French Navy's future submarine launched ballistic missile, designed to replace the M45 SLBM (In French terminology the MSBS - Mer-Sol-Balistique-Stratégique “Sea-ground-Strategic ballistic”).Each missile carries six independently targetable TN 75 thermonuclear warheads.The three-stage engine of the M51 is directly derived from the propellant boosters of Ariane 5.The missiles are a compromise over the M5 SLBM design, which is to have a range of 11,000 km (6,200 miles) and carry 10 TNO MIRV of the new generation (Tête Nucléaire Océanique, “Oceanic nuclear warhead”). The M51 will enter service in 2010.Flight testsThe M51 performed its first flight test (unarmed) on the 9 November 2006 from the French missile flight test centre in Biscarrosse (Landes). The target was reached twenty minutes later, in the north-west of the Atlantic Ocean.[1]A second successful test was carried out on the 21 June 2007