Congressional Budget Office

Alternatives for Boost-Phase Missile Defense (A CBO Study) Congressional Budget Office

A prominent part of the Bush Administration's strategy for national defense is developing and fielding defenses against ballistic missiles. To that end, the Department of Defense's Missile Defense Agency (MDA) is pursuing a layered defense composed of various systems capable of intercepting ballistic missiles at different points in their flight. For the past several years, work has primarily focused on intercepting long-range missiles during their midcourse phase (after their booster rockets have burned out but before their warheads have reentered the atmosphere). MDA plans to field initial elements of a midcourse system this year. Recently, the agency also began an effort to develop interceptors capable of hitting intercontinental ballistic missiles during their boost phase (the first few minutes after launch, before their booster rockets burn out).