Cruise Missiles

Most missiles are powered by rockets, but the cruise missile is powered by a small jet engine and is not ballistic. The missiles have wings, and they fly like planes without a pilot. Cruise missiles guide themselves to the target, flying low to avoid enemy radar. They are very accurate indeed: a cruise missile can fly 700 miles (1,126 kilometers) and then hit a designated target the size of a car.

A cruise missile can be fired from a launcher on the back of a truck, or from an airplane, a ship, or even a submerged submarine. A small rocket launches the missile, and then the rocket falls away and the missile’s jet engine takes over. Cruise missiles dropped from aircraft do not need booster rockets, because they are already traveling fast enough when they are launched. The tailfins and wings spring out from the missile’s body as it begins to fly toward its target.

The cruise missile is steered by a system called inertial guidance. The system measures how far the missile has traveled, and in which direction, from the place where it was launched. Inertial guidance is not perfect, and small errors can build up during a long flight and push the missile off course. The missile checks its position with a radar system called TERCOM (short for terrain

О An MIM-104 Patriot missile is fired into the sky. Patriot launch tubes, mounted on the backs of trucks, are deployed in conflict zones, such as Iraq and Afghanistan.

contour mapping). This system looks at the ground below it and compares the shape of the ground to a map stored in its memory. Any error found by TERCOM is used to correct the missile’s course. The latest cruise missiles also use GPS (Global Positioning System) to make sure that they stay on course.

As the cruise missile closes in on its target, it switches to a different guidance system. This uses a camera in the mis­sile’s nose to look at the view ahead and compare it to an image of the target stored in its memory. When it spots the target, it flies straight toward it.