Strategic Underpinnings of Aegis BMD at Sea
The most recent U.S. national level strategic guidance is the January 2012 Department of Defense document entitled Sustaining U.S. Global Leadership: Priorities for 21st Century Defense. Otherwise known as the Defense Strategic Guidance this publication deals with the ballistic missile threat and ties these missiles more closely with weapons of mass destruction. Thus, it provides much of the strategic underpinnings for ship-based Aegis ballistic missile defense (BMD).
Sustaining U.S. Global Leadership: Priorities for 21st Century Defense notes, “Of particular concern are the proliferation of ballistic missiles and weapons of mass destruction (WMD),” marking a clear increase in concern regarding this threat on the part of the Obama administration. In many ways, the 2012 Defense Strategic Guidance was prescient regarding what the United States is dealing with off the coast of North Korea today.
In the coming decade, BMD capabilities will be incorporated into a growing number of U.S. warships. The Aegis Weapon System in early 2012 is operational on board 23 Ticonderoga (CG 47)-class cruisers and 62 Arleigh Burke (DDG 51)-class destroyers. The Navy, in conjunction with MDA, has established a plan to increase the number of BMD-capable Aegis ships from the current 24 to 35 in 2017 to meet the demand for these assets from U.S. combatant commanders. Moreover, contemplating the global proliferation of ballistic missiles and the anticipated spread of anti-ship ballistic missiles such as the DF-21D, Navy force planners ultimately foresee a requirement that every Aegis surface combatant be BMD-capable, ultimately reaching 94 BMD-capable ships by 2024.
Then-Secretary of Defense Leon Panetta gave additional emphasis to the ballistic missile/WMD threat and the and the crucial role of Aegis BMD in a press briefing in January 2012 following the release of Defense Strategic Guidance and its companion budget document, Defense Budget Priorities and Choices. The Secretary’s detailed statement, noted, in part: “The Navy is protecting our highest priority and most flexible ships, such as Arleigh Burke destroyers. It will retire lower priority cruisers that have not been upgraded with ballistic missile defense capability [emphasis added] or that require significant maintenance, as well as combat logistics and fleet support ships.”
Aegis BMD at Sea Today
In 2013, Aegis BMD is deployed at sea in the 3.6.1 configuration, providing exo-atmospheric engagement capability with the SM-3 Block IA missile. The Navy also has 87 SM-3 missiles in its operational inventory, as well as 72 SM-3 Block IVA missiles for limited terminal BMD as well as fleet anti-air warfare defense. Significantly, an April 2011 flight test, FTM-15, demonstrated that Aegis BMD 3.6.1 and the SM-3 Block IA have a launch-on-remote (LoR) capability, which allows an Aegis warship to launch its missile based upon target data provided by off-board sensors, and thus employ the SM-3 at its maximum range. In addition, the target engaged in FTM-15 simulated an IRBM, showcasing an inherent BMD capability originally scheduled for introduction later in the decade.
Looking forward, Aegis BMD will continue the process of step-wise improvements in software, hardware, and the SM-3 missile. The Aegis BMD 4.0.1 configuration enables Aegis warships to engage increasingly longer-range, more complex ballistic missile threats using the SM-3 Block IB missile. On the ship side, the upgrade introduces new radar waveforms; improved signal processing, target tracking, and radio-frequency discrimination; and an enhanced LoR ability. Those improvements will boost the system’s ability to deal with both unitary and separating targets, the latter of which split into multiple objects that include warheads, decoys, and debris. Version 4.0.1 also facilitates better engagement coordination and furthers the system’s ability to counter multiple-missile raids. For its part, the SM-3 Block IB features an improved seeker, signal processor, and propulsion system, and like the Block IA can be employed in launch-on-remote engagements.
Aegis BMD 4.0.1 was installed in the cruiser Lake Erie for testing in 2009 and underwent extensive evaluation in 2009 and 2010. The warship also participated in the September 2011 flight test FTM-16, successfully tracking and guiding the target missile. (Ultimately, however, this test resulted in a miss.) Aegis BMD 4.0.1 will see initial fleet operational use in 2012 in two cruisers (including the Lake Erie) and two destroyers.
Future Upgrades to Aegis BMD At-Sea
The next successive upgrade is the in-development Aegis BMD 5.0, which migrates Aegis BMD capability into the commercial off-the-shelf/open-architecture computing environment and adds a multimission signal processor. This package is a key to potentially expanding Aegis BMD capability to 84 destroyers and selected cruisers in the Aegis fleet. Once Aegis BMD 5.0 is available, warships fitted with version 3.6.1 can be upgraded directly to 5.0 – instead of undergoing an interim installation of version 4.0.1 4 – at significantly lower cost. Aegis BMD 5.0 likewise provides a foundation for implementing Aegis BMD in allied warships, and will be incorporated into Aegis Ashore systems deployed to Europe.
Later in this decade, Aegis BMD 5.1 will integrate the SM-3 Block IIA missile into the combat system. Aegis warships equipped with the 5.1 configuration will be able to conduct “engage-on-remote” (EoR) intercepts that rely solely on target data provided by off-board sensors. This will increase the volume of an area that can be defended by the SM-3 missile. The SM-3 Block IIA missile itself will have a higher burnout velocity, expanding the system’s capability again faster missile targets. The Block IIA also will have a more advanced seeker that is better able to discriminate between warheads and decoys. The kinetic warhead and second and third stages of the SM-3 Block IIA will be larger than those of the Block IB, which will make the Block IIA missile the largest variant compatible with the current Mk 41 VLS. Currently in co-development with Japan, flight-testing of the Block IIA is scheduled for 2014 and initial-use certification will occur in 2018.
The next step in this progression of the Standard Missile will be the SM-3 Block IIB – still in the concept and planning stage – which will have an even higher burnout velocity and greater divert capability. This will give the SM-3 variant a boost-phase intercept capability against long-range missiles, including some ICBMs, and again enable it to defend a larger volume of area than its predecessors. An even larger missile, the SM-3 Block IIB will require modifications to the vertical launch systems onboard BMD-equipped Aegis warships. This missile is scheduled to enter service around 2020.
In the coming decade, BMD capabilities will be incorporated into a growing number of U.S. warships. The Aegis Weapon System in early 2012 is operational on board 23 Ticonderoga (CG 47)-class cruisers and 62 Arleigh Burke (DDG 51)-class destroyers. The Navy, in conjunction with MDA, has established a plan to increase the number of BMD-capable Aegis ships from the current 24 to 35 in 2017 to meet the demand for these assets from U.S. combatant commanders. Moreover, contemplating the global proliferation of ballistic missiles and the anticipated spread of anti-ship ballistic missiles such as the DF-21D, Navy force planners ultimately foresee a requirement that every Aegis surface combatant be BMD-capable, ultimately reaching 94 BMD-capable ships by 2024.
Congress Is Engaged
There is intense Congressional scrutiny on the Navy regarding the adequacy of its sea-based missile defense force structure. The Jan. 5, 2010 Fiscal Year 2011 (FY11) Ike Skelton National Defense Authorization Act (NDAA) (H.R. 6523) directed the Navy to submit a force structure review regarding the Navy’s capacity to meet the most critical demands for multimission surface combatants. Reflecting the surging demand for Aegis BMD-capable ships, this year’s report noted: “The Navy does not have the capacity to meet all Geographic Combatant Commander (GCC) demands for BMD-capable surface combatants without breaking established Chief of Naval Operations Personnel Tempo limits.”
Supporting this Congressional Interest is an ongoing series of updates on Aegis BMD written by Congressional Research Analyst Ron O’Rourke. His most recent report, dated March 14, 2013, Navy Aegis Ballistic Missile Defense (BMD): Program: Background and Issues for Congress, is essential reading for a deeper understanding of Aegis BMD.