KKV is an acronym for Kinetic Kill Vehicle. It usually refers to a maneuvering weapon, as opposed to the kinetic penetrators used in tank ammunition. Examples include the FLAGE missile interceptor prototype or the 'brilliant pebbles' envisioned for SDI. The principle is simple; the kinetic energy released in an impact between the interceptor or weapon and its target is enough to either destroy the target or at least divert it from its intended course or trajectory. Usually this is because one or both of the two is moving at extremely high speed when the collision occurs, but this need not be the case- a KKV designed to damage or destroy a pressurized or otherwise fragile spaceborne target need not move extremely fast.