aegis

Background

During the 1960's, advances in anti-ship missiles meant that reaction time, firepower and operational availability in all environments did not match the threat. To counter this, an operational requirement for an Advanced Surface Missile System (ASMS) was promulgated and a comprehensive engineering development program was initiated. ASMS was renamed AEGIS in December 1969.

The sophistication and complexity of the AEGIS combat system were such that the combination of engineering with AEGIS/AEGIS equipped ship acquisition demanded a new approach, which was achieved by the establishment of the AEGIS shipbuilding project at Naval Sea Systems Command (NAVSEA PMS-400) in 1977. This organization combined hull mechanical and electrical systems, combat systems, computer programs, repair parts, personnel maintenance documentation and tactical operation documentation into one unified organization to create the AEGIS cruisers and destroyers. This is underpinned by an organization that has both the responsibility and authority to simultaneously manage development/acquisition, combat system integration and lifetime support.

The result of this activity was the AEGIS weapon system which can defeat an extremely wide range of targets from wave top to directly overhead. AEGIS is extremely capable against anti-ship cruise missiles and manned aircraft flying in all speed ranges from subsonic to supersonic. The AEGIS system is effective in all environmental conditions having both all-weather capability and demonstrated outstanding abilities in chaff and jamming environments. The AEGIS system was designed as a total weapon system, from detection to kill.

Description

The heart of the AEGIS systems is an advanced, automatic detect and track, multifunctional phased-array radar, the AN/SPY-1. This high-powered (4 MW) radar is able to perform search, track and missile guidance functions simultaneously with a capability of over 100 targets. The first Engineering Development Model (EDM-1) was installed in the test ship, USS Norton Sound (AVM 1) in 1973. The system's computer-based command and decision element is the core of the AEGIS combat system. This interface makes the AEGIS combat system capable of simultaneous operation against a multi-mission threat: anti-air, anti-surface and anti-submarine warfare.

The first AEGIS ships were based on the hull and machinery designs of 'Spruance' class destroyers. Originally identified as a guided missile destroyer, DDG-47 class, the class was re-designated a guided missile cruiser. The first ship of the class, USS Ticonderoga (CG 47), was commissioned in January 1983. 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) introduced the AN/UYK-43/44 computers, which provide increased processing capabilities.

In 1980, the preliminary plans for a smaller ship with AEGIS capabilities were studied. Advances in technology allowed the building of an AEGIS system compatible with a smaller ship while maintaining multi-mission capabilities. A smaller ship was designed using an improved sea-keeping hull form, reduced infra-red and radar cross section and upgrades to the AEGIS Combat System. The first ship of the DDG 51 class, Arleigh Burke, was commissioned in 1991. DDG 51s were constructed in flights, allowing technological advances during construction. Flight II, introduced in 1992, incorporates improvements to the SPY radar and the Standard missile, active electronic countermeasures and communications. Flight IIA, introduced in 1994, added a helicopter hangar with one anti-submarine helicopter and one armed attack helicopter. The Aegis program has also projected reducing the cost of each Flight IIA ship by at least US$30 million.

AEGIS Combat Systems are upgraded in baselines as follows:

Baseline 2 (CG 52-58) consists of the Vertical Launching System, TOMAHAWK Weapon System and Anti-Submarine Warfare upgrades

Baseline 3 (CG 59-64) includes the AN/SPY-1B radar and AN/UYQ-21 consoles