The Aegis Weapon System (AWS) is a centralized, automated, command-and-control (C2) and weapons control system that was designed as a total weapon system, from detection to kill. The heart of the system is the AN/SPY-1, an advanced, automatic detect and track, multi-function phased-array radar. This high-powered (four megawatt) radar is able to perform search, track, and missile guidance functions simultaneously, with a track capacity of more than 100 targets. The first Engineering Development Model (EDM-1) was installed in the test ship, USS Norton Sound (AVM 1) in 1973.
The computer-based command and decision element is the core of the Aegis combat system. This interface makes the Aegis combat system capable of simultaneous operations against multi-mission threats: anti-air, anti-surface and anti-submarine warfare. The first Aegis ship, USS Ticonderoga (CG 47), was commissioned in 1983 and deployed six months after commissioning.
The Navy built the first Aegis cruisers using the hull and machinery designs of Spruance class destroyers. The commissioning of USS Bunker Hill (CG 52) opened a new era in surface warfare as the first Aegis ship outfitted with the Vertical Launching System (VLS), allowing greater missile selection, firepower and survivability. The improved AN/SPY-1B radar went to sea in USS Princeton (CG 59), ushering in another advance in Aegis capabilities. USS Chosin (CG 65) was the first ship installed with the AN/UYK-43 computers, which provide increased processing capacity.
A smaller ship was designed using an improved sea-keeping hull form, reduced infrared and radar cross section and upgrades to the Aegis Combat System. The first ship of the DDG 51 class, USS Arleigh Burke, was commissioned on the Fourth of July, 1991. The DDG 51 class was named after the legendary Admiral Arleigh Burke, the most famous destroyerman of World War II.
DDG 51s are constructed in flights, allowing technological advances during construction. The first 21 destroyers (DDG 51 through DDG 71) were identified as Flight I DDGs. Flight II, introduced in fiscal year 1992 (FY 92), incorporated improvements to the SPY radar, active electronic countermeasures and communications. Flight IIA, introduced in FY 94, consisted of DDG 79 and follow-on destroyers, which added a helicopter hangar with space for two multi-mission helicopters. AN/SPY-1D(V) introduced improvements in littoral environments, starting with USS Pinckney (DDG 91).
The Navy has decided to restart construction of new DDG 51s. The new Aegis destroyer will utilize software componentized to enable reuse and networked-based COTS computing system infrastructures during installation, modifications, and future upgrades. The restarted Aegis destroyers (DDG Restart) will incorporate the same new technologies, as an Aegis Modernized Destroyer such as the Multi- Mission Signal Processor (MMSP), the Surface Electronic Warfare Improvement Program (SEWIP), Ballistic Missile Defense (BMD) 5.0, and the AN/SQQ-89(V) Anti-Submarine Warfare/Undersea Warfare Combat System (ASWCS/USWCS). In addition to this DDG restart effort, the Navy is currently making plans for a follow-on version of the DDG 51 class that will be called DDG Flight III.
In an effort incorporate advances in technology into in-service ships, and to keep pace with emerging threat, the Aegis Modernization (AMOD) program was introduced. AMOD produces system upgrades via the Advanced Capability Build (ACB) process for CG and DDG Modernization, DDG Restart, and DDG FLT III.
The first iteration of this process, ACB-08 / Technology Insertion (TI) 08, brought CGs 52 through 58 increased warfighting capabilities during CG Modernizations that began in 2009. ACB-08 separated hardware from software, allowing for commercial off-the shelf (COTS) computer processors, and re-uses elements of the Aegis Baseline 7.1R computer program code, while integrating improved system capabilities. The current Advanced Capability Build, ACB-12, has transitioned to Aegis Baseline 9 (BL 9) and brings increased warfighting capability with regard to Integrated Air and Missile Defense (IAMD), Naval Integrated Fire Control-Counter Air (NIFC-CA), the SM-6 missile, the Evolved SeaSparrow Missile (ESSM), Close-in Weapon System (CIWS) BLK 1B, and MMSP. The follow-on to ACB-12 will be ACB-16, which will integrate the following additional capabilities: improved IAMD capability with new Standard Missile; SPQ-9B; MH-60R; Surface Electronic Warfare Improvement Program (SEWIP) BLK II with Radar Designated Decoy Launch; and updates to Total Ship Training Capability (TSTC) Training, Interoperability, and C4I.
BL 9 initiated a Common Source Library (CSL) program for Aegis and brought in the first third-party developed software element, Track Manager/ Track Server, as well as the competitively awarded Common Display System (CDS) and Common Processor System (CPS). The CSL enables software reuse and commonality across all modernized and new construction Aegis Combat System configurations. Specifically, the Aegis CSL allows for the use of common tactical software across four different Aegis configurations, including Air Defense Cruisers, IAMD Destroyers with integrated Ballistic Missile Defense (BMD) capability, New Construction Integrated Air and Missile Defense Destroyers, and Aegis Ashore (AA) with integrated BMD capability.
There are currently 74 U.S. Navy ships in service with the Aegis Weapons System installed: 22 Cruisers and 52 Destroyers.