Ohio Subs Would Be Best Basing Mode for New Interceptor Missile

Sea Power, Nov 2004 by Pavlos, John, Hasslinger, Karl

The U.S. ballistic-missile defense system will be significantly enhanced with the deployment of the new Kinetic Energy Interceptor (KEI) being developed to intercept hostile missiles in the boost and midcourse phases of attack. The KEI is a large missile, which is necessary for it to develop the acceleration and speed needed by the missile defense system.

Studies are under way to evaluate the most effective way to deploy this capability at sea. Work by General Dynamics Electric Boat indicates that basing interceptors aboard nuclear-powered ballistic-missile submarines would provide significant benefits in terms of operations, system reliability and survivability.

Among potential launch platforms at sea, nuclear submarines have unequaled mobility, stealth and endurance. The ability to quickly reposition submarines around the world with almost no logistic support provides significant operational and political flexibility. Together, these attributes could provide a persistent and credible deterrent. Moreover, the subs' stealth allows them to operate in close proximity to enemy shores without risk of political provocation or military action.

This proximity is critical for a successful intercept during the attacking missile's boost phase, which lasts only several minutes. To be effective, the defender has to be close to the target prior to launch. Even then, speed is another essential ingredient of success.

The defending KEI missile, designed to operate at more than twice the speed of the existing SM-3 defensive missile, has to launch quickly and streak to its target even before the attacker's final trajectory is known. Continuous in-flight updates are provided to the interceptor by terrestrial communication systems that can be located at considerable distance outside the threat's reach.

Technical assessments conducted by Electric Boat indicate that interceptor launch cycle times from a submarine provide attractive capabilities for Missile Defense Agency (MDA) planners. Also, submarine basing for defensive missiles would be far more efficient than other sea base options, which involve surface platforms that would require logistical support or defensive escorts.

Finally, while operating submerged, submarines provide very stable, all-weather launch platforms and are immune to cruise missiles, ballistic missiles, small boat attacks and chemical, biological and radiological weapons.

There are two submarine platforms the MDA could leverage for a sea-based missile-defense capability. The better known of these is the Ohio-class nuclear-powered ballistic-missile submarine, the SSBN. These boats represent the most survivable leg of the country's strategic triad. They routinely patrol in open ocean areas carrying up to 24 Trident ballistic missiles capable of reaching any area in the world.

The second platform is the Ohio-class nuclear-powered guided-missile submarine, the SSGN. It will operate close to potential trouble spots and carry 154 conventional cruise missiles along with Special Operations forces.

Given their current missions, the two types of Ohio-class boats could operate in tandem as they take on missile defense as an ancillary role. Prowling close to shore, the SSGN would provide boost-phase defense. Patrolling at greater distances and in deeper waters, the SSBN would strike hostile missiles that ascend to midcourse flight.

Armed with the KEI and the largest tactical cruise missile arsenal of any warship, the SSGN would provide a dual defensive capability against attacking ballistic missiles. Its cruise missiles could be used for a variety of missions, including pre-emptive strikes on enemy missile sites.

Using some missile tubes for the KEI, the SSGN also would strike hostile missiles in the boost phase, making the SSGN a key part of the nation's multilayered missile defense system.

The SSBNs, prowling mid-ocean areas where they are virtually impossible to locate, would carry a mix of strategic and KEI missiles, enabling them to continue deterrent patrols while providing a defensive capability against hostile missiles in the midcourse phase of flight.

This approach would not add deployment requirements to our naval forces. The subs' additional role would not conflict with any current payload options since all submarine missile tubes, including the SSGN and SSBN, carry only offensive weapons. Submarines defend themselves by virtue of their stealth - adversaries can't find them.

Electric Boat built 18 Ohio-class submarines between 1979 and 1996. They were designed from the keel up to launch large ICBMs as part of the Trident missile system, comprising the submarines, missiles, bases, crews, communications and logistics. By grouping all these functions and managing them as one system, it has provided extreme readiness and reliability.

The Ohio class comprises large submarines each displacing 18,750 tons and housing 24 independent launch tubes, each more than 7 feet in diameter and 44 feet tall. The boats have retained large stability and weight margin reserves even after more than 20 years of service. They would fire their KEI missiles while fully submerged, providing a very stable launch platform that is virtually insensitive to the sea state. Because Ohio-class submarines were designed with large missiles in mind, KEI would require only minimal modifications to the missile tubes.