Strategic Missiles

Trident, a nuclear weapon, is the U. S. Navy’s submarine-launched ballistic missile (SLBM). A Navy submarine can carry up to twenty-four Trident missiles. The latest Trident missile model, the Trident II (D5), can hit targets 4,600 miles (7,400 kilometers) from wherever it is launched. The British Royal Navy is also armed with Trident.

Nuclear missiles such as Trident are deterrent, or strategic, weapons. A deter­rent is so terrible that its mere existence deters an enemy nation from attacking. A nuclear attack would trigger an unstoppable, devastating nuclear retali­ation. This policy is sometimes known as mutually assured destruction, or MAD.

Most missiles have one warhead—the exploding part in the missile’s nose. Strategic missiles often have several warheads that can be aimed at different targets. The warheads are located on a part called a bus. The bus is blasted into

О This drawing shows a typical multiple independently targetable reentry vehicle (MIRV)— the multiple warhead of a strategic missile.

the upper atmosphere. Its guidance system aims it at the first target and releases one warhead. The warhead heads back to Earth and falls on that target. Meanwhile, small rocket thrusters have turned the bus to aim at another target and released another warhead. Trident can carry up to twelve warheads. This type of warhead is called a MIRV, which stands for multiple independently targetable reentry vehicle.