Ballistic missile 弹道导弹

A ballistic missile is a missile (rocket) that follows a ballistic trajectory with the objective of delivering one or more warheads to a predetermined target. A ballistic missile is only guided during relatively brief periods of flight (there are unguided ballistic missiles as well, such as 9K52 Luna-M, although these may well be considered rockets), and most of its trajectory is unpowered and governed by gravity and air resistance if in the atmosphere. This contrasts to a cruise missile, which is aerodynamically guided in powered flight. Long range intercontinental ballistic missiles (ICBM) are launched at a steep, sub-orbital flight trajectory and spend most of their flight out of the atmosphere. Shorter range ballistic missiles stay within the Earth's atmosphere.