The program is part of the Aegis Ballistic Missile Defense System and permits the integration of the SM-3 missile with the Aegis Weapon System deployed on US Navy destroyers and cruisers. The Missile Defense Agency is relying on the Aegis Ballistic Missile Defense System with its Standard Missile 3 to intercept short and medium range ballistic missile threats in mid course flight. Under this setup, the Missile Defense Agency’s is provided with a mobile sea-based component for the Ballistic Missile Defense System (BMDS). The Block IIA designation for the missile variant not only identifies the evolutionary ‘spiral’ development model of gradually incrementing newer capabilities to system, but also differentiates the Block IIA from the previous Block IA. The Block IIA is the largest, most powerful variant yet of the SM-3 family. It is equipped with 21-inch diameter 2nd and 3rd stage rocket motors allowing it to intercept longer range ballistic missile LRBM. Alike the older SM-2 and SM-3 and even the RGM109 Tomahawk ship-launched missiles, the Block IIA is also launched from the ubiquitous Mk 41 Vertical Launching System. The system’s versatility has attracted foreign interest, with Japan joining the development team in an effort to deploy the system on its 4 KONGO Class Destroyers.
The Boost Phase
The SM-3 family uses in-flight radio-communication with the ship radar via the Aegis fire control system to plan the point of intercept with a ballistic threat in real time. The flight sequence first employs the 21-inch diameter first stage Mk 72 booster followed by the Mk 104 second stage dual thrust rocket motor. The Mk 136 Third Stage Rocket Motor (TSRM) provides enough thrust for the SM-3 to reach the Earth atmosphere where the SM-3 Kinetic Warhead will deploy from the rocket nose cone housing it. At this point the Kinetic Warhead will initiate its interception phase towards the ballistic threat. On SM-3 Block IIA, the Mk 104 and Mk 136, respectively second and third stage rocket motors which are 13.5 inches in diameter are replaced by larger 21-inch diameter second and third stage rocket motors, giving that variant a uniform look as well as 45-60% more velocity at each stage burnout.
The Intercept Phase
Upon arrival in the atmosphere, the nose cone carrying the SM-3 Kinetic Warhead will separate from the third stage rocket motor booster. Freed from the nose cone, the KW uses its long wavelength imaging infrared seeker to acquire the target. The Divert and Attitude Control System DACS is said to provide extreme maneuverability allowing the KW to lock in and engage the incoming ballistic missile threat at an extremely high velocity, disintegrating it on impact. According to Raytheon Missile Systems Co, by the time the kinetic warhead impacts with the threat, it has already selected the most lethal point of impact along the threat’s body as well as reached a level of kinetic energy similar to a “10-ton truck traveling at 600 mph”. With the Aegis Ballistic Missile defense System, the MDA has claimed 22 out of 25 successful test interceptions, one of which involved two interceptors destroying two targets simultaneously.
US Navy Readiness
The MDA identifies the following US Navy Aegis-capable forces: 22 Aegis Ballistic Missile Defense capable ships comprised by 5 Ticonderoga CG-47 Class Aegis Cruisers and 17 Arleigh Burgh DDG-51 Aegis Class Destroyers. The U.S. Navy currently maintains 16 such ships assigned to the Pacific Fleet and 6 with the Atlantic Fleet. An additional 6 destroyers from the Atlantic Fleet will convert to the Ballistic Missile Defense mission before the end of the year as planned by the Secretary of Defense and a few more soon after until 32 battle ships are ready by the end of 2013. The Congressional Research Service sees 23 ships ready by the end of this year but 41 by Fiscal Year 2016, along with 111 SM-3 interceptors delivered at the end of Fiscal Year 2011 to 341 at the end of Fiscal Year 2016.
The SM-3 IIA cost is estimated at $20 to 24 million per round by Congressional Research Service and Congress Budget Office analysts. Missile Defense Agency’s proposed budget of $2.38 billion in procurement and development funding for Aegis BMD efforts projects $318.8 million for FY 2011, $424.5 million for FY 2012, $357.2 million FY 2013, $279.4 million for FY 2014, $203.6 million for FY 2015 and $25.2 million for FY 2016. From our analysis of the 2011 Defense Budget legislation passed by the House of Representatives on May 26th 2011 (HR1540), the appropriation funds allocated for FY2012 are $615 million in procurement and $965 million for the Aegis Ballistic Missile defense research, development, test and evaluation.
Awaiting the SM-3 Block IB
The SM-3 Block IIA which will undergo testing until 2014 is already set to be replaced by a still more powerful variant again relying on the continuous ‘evolutionary’ process to add capabilities to an existing system. The Missile Defense Agency recently awarded Raytheon with a $312 Million contract for procurement of the new SM-3 Block IB using an improved signal processor and two-colors all reflective infrared seeker , a throttleable divert and attitude control system TDACS for improving target discrimination and therefore range.