Aegis Ballistic Missile Defense
The Aegis Ballistic Missile Defense (BMD) System, a part of the Aegis Combat System, is the sea-based component of the Ballistic Missile Defense System (BMDS). It uses variants of the Standard Missile-3 (SM-3) to intercept short to intermediate-range ballistic missiles during midcourse. The system is integrated on certain U.S. Navy Ticonderoga-class Cruisers (CG) and Arleigh Burke-class Guided Missile Destroyers (DDG). The land-based variant, known as Aegis Ashore, is currently deployed in Deveselu, Romania as part of the NATO missile defense system.
More broadly, the Aegis Combat System also provides air and fleet defense against enemy aircraft and cruise missiles using variations of the Standard Missile-2 (SM-2), Standard Missile-6 (SM-6), and the Evolved SeaSparrow Missile (ESSM), and ship defense systems such as the Phalanx Close-In Weapon System (CIWS). It also controls the firing of Tomahawk land-attack cruise missiles.
https://missilethreat.csis.org/system/aegis/
