The Aegis cruiser USS Cape St. George (CG 71) returns to Pear Harbor, Hi., Jan. 25, 2014.

The Aegis cruiser USS Cape St. George (CG 71) returns to Pear Harbor, Hi., Jan. 25, 2014. U.S. Navy photo by Mass Communication Specialist 1st Class Daniel Barker/Released

Navy's Aegis Missile Defense Is Ready for Prime Time

Say what you will about ground-based interceptors, but Navy’s Aegis ballistic missile defense system is already on patrol and ready. By Scott C. Truver

While a key element of the United States ballistic missile defense strategy – ground based interceptors -- might not be ready for “prime time,” clearly that’s not the case for the U.S. Navy’s Aegis weapon system. Aegis is at sea, today, aboard 30 guided-missile cruisers and destroyers. And if the Navy and Missile Defense Agency budgets can survive near-term defense cuts, this sea-based force could increase to more than 40 ships by 2018.  

In combination with two Army systems -- the Patriot Advanced Capability-3, or PAC-3, and Terminal High Altitude Area Defense, or THAAD -- Aegis is the third “leg” of the nation’s regional ballistic missile defense system. Although it’s focused on defeating regional threats from the likes of North Korea and Iran, the Aegis system has the potential to counter longer-range weapons that threaten the U.S.

In 2002, the Navy launched a program to integrate new ballistic missile defense capabilities in existing Aegis anti-air (against aircraft and cruise missiles) warships. This important mission objective has been achieved primarily through a series of changes to the ships’ SPY-1 phased-array radars and their combat systems. The Navy and MDA produced two variants of the combined combat system and surface-to-space missiles: Aegis BMD 3.6 with SM-3 Block IA missile and Aegis BMD 4.0 with the SM-3 Block IB missile. The former system is already deployed on 30 warships, while the “second-gen” Aegis capability is installed and operating on five Aegis BMD ships in early 2014 -- with work to upgrade three more underway.

Stressed by a series of increasingly demanding tests, in 2008 Aegis was the first element of the national ballistic missile defense system to be declared operationally suitable and effective by the Defense Department’s director of operational test and evaluation. OT&E’s latest report highlights Aegis testing, noting the system has successfully demonstrated the capability to conduct “end-to-end engagements” of short-range and medium-range ballistic missiles.

The improved Aegis system represents a significant increase in capabilities. The second generation Aegis system is designed to take on increasingly long range, more sophisticated and larger numbers of ballistic missiles, simultaneously. On Sept. 18, the Aegis cruiser Lake Erie succeeded on the first attempt to engage a sophisticated, separating short-range ballistic missile target with two SM-3 Block IB missiles that were launched and guided almost simultaneously to a successful intercept. Two weeks later, the Lake Erie launched a single missile that shot down a short-range ballistic missile target outside of the Earth’s atmosphere. This was the 28th successful intercept in 34 flight test attempts since 2002 for the Navy’s Aegis/SPY-1 BMD system. Of course, even unsuccessful intercepts still provided valuable test data.

In real-world tests of the in-service SM-3 Block IA missile, Aegis has demonstrated the longest-range target intercept of any system. In addition, Aegis was the first system to demonstrate ascent-phase intercepts, the salvo launching of interceptor missiles and the simultaneous conduct of missile defense and anti-air warfare operations.

Because of its adaptability, flexibility and effectiveness, the land-based, “Aegis Ashore,” installation is being constructed in Romania and in Poland as part of the European Phased Adaptive Approach strategy. The Standard SM-3 missile sites and Aegis fire control complex will be linked to a radar site in Turkey and a command and control center in Germany to defend Western Europe against possible missile attacks from Iran or others.

And, several members of Congress have speculated that “Aegis Ashore” facilities on the U.S. Atlantic and Pacific coasts might also contribute to the defense of America and its territories. More advanced versions of the missiles are in development, in particular the SM-6, an improved terminal-phase interceptor.

Several countries concerned with ballistic missile threats have recognized Aegis effectiveness have chosen the Aegis weapon system for their warships. Australia, Japan, South Korea, Norway and Spain have constructed Aegis warships, with six of the Japanese Aegis destroyers having been upgraded to the new capability. Others are interested in acquiring the system in the near future.

Although there might be doubts about the current effectiveness of the U.S. ground-based interceptor capabilities in Alaska and California, Aegis ballistic missile defenese is at sea, on patrol and ready.

Scott Truver is director of the TeamBlue National Security Programs group at Gryphon Technologies, an Aegis program contractor. He has supported Aegis programs since 1977.