Aegis Combat System - Overview

Overview

The Aegis Combat System (ACS) is an advanced command and control (command and decision, or C&D, in Aegis parlance), and weapon control system (WCS) that uses powerful computers and radars to track and guide weapons to destroy enemy targets.

The ACS is composed of the Aegis Weapon System (AWS), the fast-reaction component of the Aegis Anti-Aircraft Warfare (AAW) capability, along with the Phalanx Close In Weapon System (CIWS), the Mark 41 Vertical Launch System. Mk 41 VLS adopts a modular design concept, which result in different versions that vary in size and weight. The length comes in three sizes: 209 in (5.3 m) for the self-defense version, 266 in (6.8 m) for the tactical version, and 303 in (7.7 m) for the strike version. The empty weight for a 8-cell module is 26,800 lb (12,200 kg) for the self-defense version, 29,800 lb (13,500 kg) for the tactical version, and 32,000 lb (15,000 kg) for the strike version, thus incorporating anti-submarine warfare (ASW) systems, and Tomahawk Land Attack Cruise Missiles (TLAM). Shipboard torpedo and naval gunnery systems are also integrated.

AWS, the heart of Aegis, comprises the AN/SPY-1 Radar, MK 99 Fire Control System, WCS, the Command and Decision Suite, and SM-2 Standard Missile family of weapons; these include the basic RIM-66 Standard, the RIM-67 extended range missile, and the newer RIM-161 designed to counter ballistic missile threats. A further SM-2 based weapon, the RIM-174 Standard ERAM is currently in testing, and may be integrated into the system in the near future. Individual ships may not carry all variants; weapons load-outs are adjusted to suit assigned mission profile. The Aegis Combat System is controlled by an advanced, automatic detect-and-track, multi-function three-dimensional passive electronically scanned array radar, the AN/SPY-1. Known as "the Shield of the Fleet", the SPY high-powered (6 megawatt) radar is able to perform search, tracking, and missile guidance functions simultaneously with a track capacity of well over 100 targets at more than 100 nautical miles (190 km). However the AN/SPY-1 Radar is mounted lower than the AN/SPS-49 radar system and so has a reduced radar horizon.

The Aegis system communicates with the Standard missiles through a radio frequency (RF) uplink using the AN/SPY-1 radar for mid-course guidance of the missile during engagements, but still requires the AN/SPG-62 radar for terminal guidance. This means that with proper scheduling of intercepts, a large number of targets can be engaged simultaneously.

The computer-based command-and-decision element is the core of the Aegis Combat System. This interface makes the ACS capable of simultaneous operation against almost all kinds of threats. The Aegis Ballistic Missile Defense System program is intended to enable the Aegis system to act in a sea-based ballistic missile defense function, to counter short- and medium-range ballistic missiles of the variety typically employed by a number of potential opponent states.