A midcourse thinning decision model for an exoatmospheric missile defence system

Two models, a gross planning and a thinning decision model, are proposed to thin out an attack of long-range ballistic missiles (ICBM) in the exoatmospheric region to avoid overburdening the defense components in the endoatmosphere. Various cost functions and constraints are examined to determine what means are necessary to best achieve a zero leakage (no penetration) and a numerical example employing 10 ICBM's and four phases is analyzed. It is concluded that the main objectives of an ICBM midcourse defense system are to: (1) alleviate the workload of a saturated terminal defense system, (2) extend travel time for the defense to make several responses to the same threats, and (3) increase the interaction and communication between the terminal defense and the midcourse defense systems.