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An essential National Capability called for under the Sea Power 21 constructs of Sea Strike and Sea Shield is the ability of the United States to project and sustain naval forces in anti-access or area-denial environments common to littoral regions around the world. This required capability consistently ranks as a high priority under various requirement assessments such as the Quadrennial Defense Review (QDR), the Defense Planning Guidance (DPG), and the newly established Naval Capabilities Pillar (NCP) of the Naval Capabilities Development Process (NCDP) which identifies capability gaps.

The joint vision is evolving that increases the need for the submarine to perform additional or expanded missions in littoral regions. Of high interest are the capabilities to strike with surprise from close-in, participate in interdiction operations against enemy mobilization efforts, provide Special Operations Forces (SOF) support at short and long ranges, and support battle space preparation operations by providing persistent Intelligence, Surveillance, and Reconnaissance (JSR) for Joint operations under anti-access or area-denial environments. In addition to the traditional threats, the deployed naval forces are now faced with the non-traditional and asymmetric threats of coastal surveillance aircraft and high speed small boats.

The Littoral Warfare Weapon (LWW) system is envisioned as providing the submarine force and Battle Force Commander with the appropriate and sufficient firepower necessary to address the asymmetric littoral target set and, in parallel, improve its ability to accomplish its required missions. By incorporating more decisive Joint capabilities, the Submarine Force can better accomplish the Power Projection and Force Protection elements of Sea Power 21 ‘ s constructs of Sea Strike and Sea Shield.

2.0 THE “NEED”

As noted above, the required capabilities documented for future submarine forces include uninterrupted strike operations from close-in, friendly SOF support, persistent ISR, and interdiction operations against enemy mobilization units. The Submarine Force can currently operate effectively in a littoral, anti-access environment, however, current submarine weapons were not designed for the emerging asynunetric target set. If stealth is compromised against threats, the current tactic is to go deep and reposition to regain a stealthy posture. This tactic has the potential to temporarily interrupt ongoing offensive operations, such as Strike and ISR. The submarine force needs the capability to neutralize the threat while continuing offensive operations. Specifically, the Submarine Force requires a fast reaction weapon of appropriate accuracy, lethality, and range capability to deter or defeat hostile aircraft and small-to-medium sized high speed, shallow draft surface craft. A major consideration is that the weapon system can be employed under the rules of engagement for littoral regions. Any solution should leverage current submarine systems for targeting, weapon preparation, and launching while having compatibility with Los Angeles, Virginia, and Ohio Class SSGN submarines and the potential compatibility with US Surface Naval and Coalition platforms.


The L WW system will provide a revolutionary increase in Force Protection for Joint operation in the littoral regions of the world. Asymmetric threats such as High Speed Patrol Craft (HSPC) and aircraft represent a stressing challenge to the Joint Battle force security. In order to be effective in both a deterrent and wartime environment, the Joint Force must be able to operate with impunity in the face of these asynunetric threats. Recent Joint Capabilities War Games have highlighted the need for enhanced capability in this area. The submarine, which often deploys long before other Joint and Combined assets to operate clandestinely for long periods of time in far forward locations, is ideally suited to detect and engage the Air and HSPC threat early in their operation and prior to Anti-Surface Cruise Missile (ASCM) launch. Typically, the submarine is in theater early in part to deploy and recover SOF. The LWW will provide the submarine with the capability to provide Force Protection for SOF during the most vulnerable periods of their operation. Focusing the submarine’s assets on anti-access and area-denial systems provides maximum benefit to follow-on forces, and contributes greatly to the overall potential for success of the Joint and Combined Force. In addition, clandestine early presence permits neutralization of these systems prior to follow-on Joint force arrival, thereby enabling access.


Naval Undersea Warfare Center(NUWC) employed an analytical model of weapon candidates to measure the attractiveness of Non-Development Item (NDI) solutions to the L WW need. Candidate weapons were evaluated in terms of operational effectiveness, cost of implementation, and system maturity. Overall, approximately sixty-five weapon system candidates were assessed. Types of systems considered included cruise and ballistic land-attack missiles, anti-aircraft missiles, anti-ship missiles, anti-tank missiles, and a variety of man-portable and hull-mounted gun-launched munitions. Results suggested that AIM-9X was among the more attractive options for the demonstration of a L WW concept and potentially as a candidate for use as an effective near term L WW solution that can be readily fielded.

Using this and other related studies as a basis, the submarine community with support from NUWC and Raytheon, formulated a related L WW system concept commonly referred to as Sea Serpent L WW and have initiated risk reduction activities to mature critical subsystem components. Ongoing Navy and Air Force programs will be leveraged to develop an L WW system that can successfully prosecute the entire spectrum of the challenging littoral target set, including Maritime Patrol Aircraft (MPA), Helicopters, HSPC and other small boat threats. Specifically, the risk reduction activities include live fire test range launches of an L WW based on missile technology from the AIM-9X program, encapsulation technology from the Submarine Payloads & Sensors program, and capsule launcher technology from the Tomahawk program.

At the time of publishing of this paper, a land based test launch of an AIM-9X, including engagement of a QH-50 rotary wing drone, was in the final planning and execution stage. Future efforts are currently being planed to focus on encapsulation technology risk reduction leading to in-water testing in FY07.


The AIM-9X is the latest member of the AIM-9 Sidewinder missile family currently in use by more than 40 nations throughout the world. This next generation Sidewinder Missile is currently in Full Rate Production. AIM-9X is a launch and leave, air combat missile that uses an imaging infrared (IR) seeker for acquisition and tracking. It can be employed in the near beyond visual range and within visual range. AIM-9X provides US and Joint Coalition fighter aircraft full day/night employment, resistance to countenneasures, extremely high off-boresight acquisition and launch envelops, greatly enhanced maneuverability, and improved target acquisition ranges. Additionally, the AIM-9X program is completing a development of a Lock On After Launch (LOAL) capability that is critical to successful employment as an LWW.

A second critical component is an encapsulation device to provide for submerged launch of the AIM-9X missile from vertical submarine launch tubes. This component will consist of a Stealthy Affordable Capsule System (SACS). SACS technology development was initiated under the DARPA/Navy sponsored Submarine Payloads & Sensors Program. This technology is expected to provide a low unit cost, universal packaging approach for integration of future payloads on existing and future submarines.

Lastly, to enable launch of LWW from Submarine vertical launch tubes, a Tomahawk Capsule Launch System (CLS) will be used to accept the encapsulated LWW. This method of vertical launch system integration provides a common interface for launch of the encapsulated L WW from vertical launch tubes on Los Angeles, Virginia, and Ohio Class SSGN Submarines. Modifications to the CLS will be minimized as much as possible, consistent with use of the SACS capsule.

These technologies will be coupled with existing Submarine organic sensors and Combat Systems to complete an end-to-end L WW system capable of detecting, classifying, targeting, and prosecuting the desired target set.


Program Executive Office Submarines (PEO SUB), PMS-415, is the Program Manager for the LWW activities. An industry team led by Raytheon Company, and consisting of Northrop Grumman Marine Systems and General Dynamics Electric Boat are performing the Sea Serpent L WW risk reduction efforts. NUWC is acting as the Technical Direction Agent (TOA) for these activities in support of PMS 415. Independent from its TOA role, NUWC also provides support to the industry team.


The Sea Serpent risk reduction efforts will help define the integration path to a low cost, highly capable L WW. In parallel with these activities, an assessment will be made as to the degree that the Sea Serpent AIM-9X based candidate approach is effective in meeting the requirements identified as part of the L WW Concept of Operations and Military Utility Assessments. Alternative candidates will be considered for transition if necessary.


The L WW capability is considered transformational because it provides for a critical component which will afford the United States the ability to project and sustain forces in anti-access or area-denial environments common to littoral regions around the world. This ability is defined as one of six QDR critical transformational goals. It also satisfies Warfighter capability gaps identified in the NCDP. The proposed L WW system will provide a critical Maritime Interdiction/Force Protection capability to engage asymmetric, anti-access threats.

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