A space sensor layer for missile defense

摘要

Ballistic missiles travel in space, and the missile defense task is by definition largely a challenge in and through the space domain. For all but very short range missiles, a considerable part of the ballistic trajectory is spent in space, after the motors burn out and before the warhead re-enters the atmosphere. Exoatmospheric midcourse intercept is the exclusive realm for two of the four currently deployed U.S. missile defense programs, Aegis Standard Missile-3 and Ground-based Midcourse Defense.