U.S. Navy AEGIS Weapons System

Naval Engineer's Journal Volume 121 Issue 3

Early AEGIS Weapons Deployment Plan

Initial funds were appropriated for the conversion of CGN-9 Long Beach to the AEGIS weapons system in the FY1977 budget, but in it's follow-on budget request in FY1978, the Ford Administration recommended rescinding the proposal.

The succeeding Carter administration not only killed the Long Beach Refit, but also killed CSGN as well. In their place would be a nuclear powered VIRGINIA class follow on – CGN-42. The five year plan in FY1978 was for sixteen DDG-47s and eight CGN-42s. However, the very next year in FY1979, the Carter Administration killed off CGN-42 - leaving only DDG-47 (later redesignated CG-47).

AEGIS Engineering Development Model 1 (EDM-1)

Radar System: AN/SPY-1 (Single Face with 90 deg coverage)
Single tracking/fire control illuminator (only single version ever built)
Single Mk 26 launcher
Radar Control Program:
Installed in two AN/UYK-7 computers
Weapon Control System:
Installed in one AN/UYK-7 computer.

Notes: Installed at RCA's Land Based Test Site (LBTS) at Moorestown. EDM-1 first tracked targets in April 1973, and testing continued for eight months until October 1973 when the system was shut down and dismantled. In December 1973, a single C-5A shipped the dismantled system to the West Coast for installation in USS Norton Sound. By May 1974, installation was complete and at-sea testing began.

(Photograph of EDM-1 at RCA's LBTS)

AEGIS Engineering Development Model 2 (EDM-2)

Notes: Was to have been installed at White Sands Missile Range to support ASMS missile testing and development. Contract had not yet been awarded when ASMS was cancelled and SM-2 substituted.

AEGIS Engineering Development Model 3C (EDM-3C)

Radar System: AN/SPY-1A (Single Face with 90 deg coverage)
Illuminator: Single Slaved Illuminator. Three other Simulated illuminators
Two Simulated Mk 26 Launchers.
Radar Control Program: Installed in a four-bay AN/UYK-7 computer.
Weapon Control System:
Installed in a four-bay AN/UYK-7 computer.

Notes: An un-used USAF Spacetrack facility that was adjacent to RCA's Engineering Factory in Moorestown was taken over by the U.S. Navy and renamed the Combat System Engineering Development Site (CSEDS) in May 1976. The old radome and all other USAF equipment was removed; and a Strike Cruiser (CSGN) superstructure was installed. Where possible, the form factor and equipment layout of the actual equipment in service was followed down to the inch for critical areas - the CIC on the third deck of CSEDS is a exact duplicate of CG-47 Ticonderoga's CIC.

The facility was commissioned as USS Rancocas on 21 May 1977, and EDM-3 equipment continued to be installed during the remainder of 1977. Integration testing began in 1978 leading to the first target track on 30 March 1978.

Later during the program, an additional AN/SPY-1A face from one of the early production systems was temporarily installed, providing 180 degrees of coverage and allowing the ability of the system to hand over targets from one array face to the next to be demonstrated. As a bonus, the very heavy air traffic over the New York City area was also tracked, stressing the maximum tracking capability of the system.

EDM-3 began the implementation of new functionality in the AEGIS Weapons System (AWS) – in which it took over tasks previously assigned to the NTDS system such as being able to remotely assign other ships' weapons to carry out AAW missions. Additionally, due to minaturization efforts, the weight of the topside phased array and illuminators of a full AEGIS system were reduced by 20 tons.

(Photograph of USAF Spacetrack Building before conversion to CSEDS by USN)
(Modern Photograph of CSEDS from Lockheed Martin's Site – 400~ KB JPG)
(Top View of CSEDS from Google Earth – circa 2004)

AEGIS Engineering Development Model 4 (EDM-4)

Notes: Used for land based testing of SPY-1B and SPY-1D components.

AEGIS Engineering Development Model 4B (EDM-4B)

Notes: Used for land based testing of SPY-1D(V) components.

AEGIS Baseline 0

Weight: 610 tons
Software Size: 802,500 words
Computers: AN/UYK-7 and AN/UYK-20

Notes: Installed on CG-47 through 48.

AEGIS Baseline 1

Computers: AN/UYK-7 and AN/UYK-20

Notes: Installed on CG-49 through 51. Added LAMPS III support

AEGIS Baseline 2

Notes: Installed on CG-52 through 58. Added VLS and TLAM support.

AEGIS Baseline 3

Weight: 650 tons
Software Size: 1,010,000 words
Computers: AN/UYK-7 and AN/UYK-20

Notes: Installed on CG-59 through 64. One-third of the code was totally new.

AEGIS Baseline 3A

Notes: Modernization of older AEGIS systems to be compatible/equivalent with Baseline 3.

AEGIS Baseline 4

Weight: 656 tons
Software Size: 3,420,500 words (about 4~ million lines of code)
Computers: AN/UYK-43 and AN/UYK-44

Notes: Installed on CG-63 through 73 and DDG 51 through 67. Program size growth was caused by conversion of many older programs to run on newer computers, and additional integration of sub-system modules which previously were contained on separate disk modules into the core program, allowing faster execution. Additionally, new provisions for increased battle-group management capability via preset doctrines and rules were added. With this version, duplicate copies of the system program were also carried to guard against partial system failure. Cost of this was 28% as much as the original AEGIS program.

AEGIS Baseline J1

Notes: Japanese version of Baseline 4.

AEGIS Baseline 5

Notes: FY92 buy, installed on DDG-68 through 78. Originally for Flight III Burkes, transferred to Flight II.

AEGIS Baseline 5 Phase 1

Notes: Adds support for SM-2ER.

AEGIS Baseline 5 Phase 2

Notes: Integration of all previously planned improvements except for JTIDS/Link 16, for backfitting to Baseline 4 ships. Among the improvements was TIP (Track Initiation Processor), which screened transistents to reduce processor load and allowing for better detection of small targets in sea clutter.

AEGIS Baseline 5 Phase 3

Software Size: In excess of 6.5 million lines

Notes: Adds ATWCS for Tomahawk and SLAM control. Color displays and JTIDS/Link 16 are installed.

AEGIS Baseline 6

Notes: Integrates SPY-1 updates with the overall combat system. Provisions for embarked helicopters are added. A new fiber-optic bus system for data multiplexing and interior voice communications is integrated.

AEGIS Baseline 6 Phase 1:

Notes: Deletes the missile loading crane in VLS; adds the Kingfisher mine detection system to the SQS-53C.

AEGIS Baseline 6 Phase 2 (6.1)

Notes: Begins with DDG 80. Begins movement of AEGIS system over to open architecture, using increasingly more COTS equipment.

AEGIS Baseline 6.3

Notes: Begins with DDG 85. Intended to add SM-2 Block IVA support, but program was canceled. Additional signal processors give the SPY-1D better discrimination against decoys launched by ballistic missiles. ESSM support is added.

AEGIS Baseline 7.1

Notes: Begins with DDG 91. Eliminates UYK-43, and replaces it with a COTS computer running an emulated UYK-43. Support for Tactical Tomahawk and SM Block IIIB is added. LAMPS Block II support is added, and the system is integrated with the remote minehunting system.

AEGIS Baseline 7.1C

Notes: Cruiser conversion for all the Ticonderogas; but the Rail Launcher ships were retired instead of being modernized.

AEGIS Baseline 7.2

Notes: Refresh program for DDG-103 to 114, with a fully open architecture to be implemented in DDG-107.

AEGIS BMD Development Line

AN/SPY-2 High Power Discriminator (HPD) Radar

Notes: Later upgrades to support BMD will add SPY-2. It is a single face X-Band AESA radar based on THAAD hardware and software, and mechanically trained like Mk 99. After cueing from the SPY-1, it will perform long range discrimination against exo-atmospheric missile threats. Due to it's extreme power, detection and tracking of targets will be limited by the radar horizon only: 1,350 km for missiles with an apogee of 100 km, and 1,800 km for missiles that have an apogee of 180 km. The Land-based THAAD radar has 25,344 X-Band T/R modules on a 9.2 square meter face. It is unknown specifically how many differences are between land-based THAAD and SPY-2.

AEGIS Long Range Surveillance & Tracking (LRS&T) 3.0

Notes: Extends radar range to 300~ miles, enabling them to support BMD “Shooters”. Has limited support for SM-3 Block I, allowing emergency use if necessary.


Notes: Fully operational track and engagement capability with support for SM-3 Block I and IA. Certified for tactical deployment by USN and MDA in September 2006.


Notes: Adds support for SM-2 Block IV, for engagement of SRBMs.


Notes: Adds an extra signal processor system devoted to BMD, for additional target discrimination capability. Adds support for SM-3 Block IA. Emergency Capability.


Notes: Same as BMD 4.0, but adds support for SM-3 Block IB, and is operationally certified. Certification is expected in 2011.


Notes: Will transition from MIL-STD computers to COTS, enabling both the AAW and BMD modes of AEGIS to be run on the same computer system, instead of on separate components as in earlier blocks.