Coast phase

The midcourse phase, also known as the coast phase or ballistic phase, or simply midcourse, is the middle portion of the flight of a ballistic missile or space vehicle. It begins after the boost phase when the engines are firing, and ends as the missile begins the reentry phase prior to impact or landing. The midcourse typically lasts from 5 to 45 minutes depending on the distance being flown. Interception of a nuclear warhead during the midcourse is difficult due to a lack of signals distinguishing it from radar decoys and other objects launched along with the warhead to confuse defenses.