This Is How a Ballistic Missile Works

The boost phase is the first of the three main launch phases of an intercontinental ballistic missile. ICBMs use one or more rockets to reach their intended height. This phase typically lasts between two and five minutes. Different types of ICBMs may use solid or liquid fuel.

Some ICBMs use multiple thrusters throughout the boost phase. For instance, the Minuteman III rocket has three rocket stages that propel the ICBM to its maximum altitude.

The second phase of an ICBM’s flight is known as the midcourse phase. This is the point in which the missile reaches outer space, reaching not only its greatest heights, but its highest speeds – potentially up to 17,000 mph.

During the midcourse phase, some ICBMs use stars to orient themselves. This method, known as a star shot, allows the ICBM to position itself towards its target upon reentry.

The third and final phase of an ICBM’s flight is known as the terminal phase. The missile begins its reentry into the Earth’s atmosphere, headed to its target.