Posted: November 02, 2019 | By: Howard Berkof


Unmanned systems are a rapidly expanding warfare segment within the overall Program Executive Office (PEO) Littoral Combat Ships (LCS) portfolio. This segment includes both unmanned surface vehicles (USVs) (shown in Figure 1) and unmanned underwater vehicles (UUVs) (shown in Figure 2), many of which are under the program management of the Unmanned Maritime Systems Program Office, PMS 406. Funding for unmanned systems within the PEO has more than doubled in the last year, as the systems are a key enabler for both LCS and the Undersea Enterprise. These systems are also an important component of the strategic vision outlined by the Chief of Naval Operations (CNO), Admiral John Richardson, in his 2016 document “A Design for Maintaining Maritime Superiority.” In that document, Admiral Richardson lays out four key “lines of effort” that the Navy will seek to implement. “Strengthening naval power at and from the sea” is one of these four lines, and that includes greater experimentation with unmanned systems and their rapid fielding.

Figure 1: Remotely Piloted USV in a Mine Hunting Exercise (Source: U.S. Navy Photo by Ken Rose).


Figure 2: UUV Being Prepared to Search for Mines During Exercise (Source: U.S. Navy Photo by Mass Communication Specialist 1st Class A. Henry).


In addition, the growing expertise and knowledge in USVs and UUVs being established within PEO LCS have become more widely recognized across the larger Department of Defense over the last year. PMS 406 is the acquisition lead for the majority of unmanned maritime systems and has established relationships and agreements with other entities working in the unmanned systems world. These relationships/agreements include science and technology work being performed by the Defense Advanced Research Projects Agency and the Office of Naval Research (ONR), advanced prototyping work being performed by the Pentagon’s Strategic Capabilities Office (SCO), and the Fleet UUV Squadron (UUVRON ONE), located at Keyport, WA. These efforts and relationships are expected to continue to strengthen in coming years.

With the growing interest and investment in unmanned maritime systems, the Navy has focused on maintaining alignment among the many stakeholder communities in the respective UUV and USV segments and establishing agreed-upon strategies and executable program plans going forward. The net result of this strategic effort is the formulation of common visions for the family of UUVs and USVs, their associated technology enablers for the Navy, and the way in which these many diverse program efforts all fit together into a cohesive strategy. From small to extra large, and across multiple warfare domains, the entire family of UUVs and USVs has been mapped into a comprehensive approach. And this stakeholder alignment and development of a common narrative across the unmanned maritime systems portfolio has been a critical program objective and continues to be key to efficient execution going forward.

From small to extra large, and across multiple warfare domains, the entire family of UUVs and USVs has been mapped into a comprehensive approach.

As part of this stakeholder alignment effort, PMS 406 is also spearheading certain enabling efforts that are germane to programs in either the USV or UUV domains. Chief among these efforts is the establishment of an Autonomy Architecture Team. This small team is composed of representatives from the Navy, research laboratories, and technical institutions with the primary objective of developing and promulgating an autonomy standard applicable to both USVs and UUVs. The intent is to develop a fully accredited standard that meets required technical criteria and can be implemented across systems by the summer of 2018.

ONR, PMS 406, and UUVRON ONE are all strengthening relationships while coordinating and developing testing and experimentation schedules to help enable seamless UUV operations with fleet assets in the coming years. For example, as part of the Innovative Naval Prototype effort, ONR is transferring several developmental UUVs to PMS 406 for support and management. PMS 406 is then providing these experimental UUVs to UUVRON to jumpstart its experience and basic handling knowledge of larger UUVs. These relationships are expected to continue to grow as additional UUVs emerge from the developmental procurement pipeline.

The funding increases going to PMS 406 are a reflection of both the technical maturation of unmanned maritime systems and a growing understanding across the Navy that unmanned  systems of all types—air, surface,  and undersea—are critical enablers  to help ensure future combat success. Admiral Richardson reinforced the role of unmanned systems, especially UUVs, following a daylong “deep dive” on UUVs held at the Naval Undersea Warfare Center in Newport, RI, in August.

This growing awareness at all levels of the special role unmanned systems will play in the Navy’s future operations was amply demonstrated in the recommendations and conclusions of three independent Fleet Architecture Studies directed by Congress and publicly released in February. Each of these studies—separately executed by the Navy’s own N81 assessment office, the federally funded MITRE Corporation, and the Center for Strategic and Budgetary Assessments (CSRA) think tank—envisions an expansive role for unmanned systems in the future fleet.

The MITRE study recommended the Navy determine how to boost production of larger UUVs, which it deemed a critical element of a growing undersea network of submarines, communications nodes, and ocean-bottom systems. Likewise, CSRA envisions the formation of unmanned squadrons composed of USVs and UUVs operating from a “mother ship.” The Navy’s N81 assessment, an independently conducted effort, was even more bold, advocating the development of USVs armed with weapons and larger numbers of UUVs.

Within PEO LCS, three essential UUV efforts are managed and coordinated by PMS 406: (1) the Knifefish UUV minehunting system, (2) the Snakehead Large Displacement Unmanned Underwater Vehicle (LDUUV), and (3) the Orca Extra Large Unmanned Underwater Vehicle (XLUUV). However, PMS 406’s efforts are not limited to these three programs alone. The office’s expansive portfolio also extends to managing the following:

  • The Navy’s new developmental Mining Expendable Delivery Unmanned Submarine Asset (MEDUSA)
  • The Unmanned Influence Sweep System (UISS) USV
  • The Mine Countermeasures (MCM) USV, which can conduct both influence minesweeping
    and minehunting operations
  • The delivery of improved production AN/AQS-20 towed minehunting sonars
  • The continued evolution of the rigid-hulled inflatable boat (RHIB)-based Minehunting USVs (MHUs) supporting 5th Fleet urgent operational requirements
  • Evolving discussions with the Office of the CNO and the Fleet on the Future Surface Combatant family of USVs
  • Collaboration with SCO’s Ghost Fleet initiative, which includes both larger USVs and an XLUUV-class system. PMS 406 is the Execution Agent for the Ghost Fleet efforts funded by the SCO

The following sections provide a program update on the current status and significant events expected to take  place across PMS 406’s unmanned portfolio over the next year.



Knifefish (shown in Figure 3) is a self-propelled UUV that operates untethered from the ship or platform from which it deploys. Operating independently in shallow ocean waters, the UUV uses a low-frequency broadband sonar to search for volume, proud (secured to ocean floor), and buried mines. The program represents a true leap ahead in technology for MCM operations. Knifefish is a critical element in the Navy’s evolving MCM efforts and its overall vision for removing ships and crews from the dangers of operating within a minefield. The 21-ft-long UUV can also be launched from other Vessels of Opportunity (VOOs), including the LCS or other surface platforms. The system is being built by General Dynamics’ Mission Systems unit.

Figure 3: Knifefish UUV (Source: U.S. Navy Photo).


Knifefish recently completed a robust series of contractor trials in Boston Harbor, MA. As part of the testing, eight mine-representative targets were scattered across an underwater range, and Knifefish successfully found and categorized all eight “mines” in a key test of the vehicle’s performance. Developmental testing will continue through the remainder of 2017, with the system expected to transition to a more robust Navy operational testing phase in 2018. Knifefish fully supported by senior Navy leaders in current budget deliberations.

Knifefish represents a true leap ahead in technology for MCM operations.

While Knifefish is well along on its development path, opportunities still exist for additional industry involvement in the program. A Pre-Planned Product Improvement effort is already envisioned for Knifefish, with PMS 406 interested in new ideas, concepts, and technologies that can improve the vehicle in the areas of launch and recovery, power and endurance, sensors and reliability, navigation precision, communications and data exchange, mission data download, and transmission.

Snakehead LDUUV

The Snakehead program has swiftly pivoted to a new acquisition strategy over the last year that seeks to speed this innovative capability to the Fleet, including starting in-water system testing by 2020, pending required funding in the budget. In January, the Snakehead LDUUV was approved as an accelerated acquisition effort, specifically as a Maritime Advanced Capabilities Office program. This approach enables the Snakehead program to use a modified, more rapid procurement approach to reduce design and development time and expedite the initial fielding of this capability. The Fleet can then conduct experimentation and assessment of the vehicle much sooner in the acquisition process and offer informed operational feedback to spur design changes and capability improvements to the Snakehead system.

Under this new, streamlined acquisition approach, initial Snakehead LDUUV vehicles will be ready for in-water testing and experimentation as early as 2020. Limited procurement of initial vehicles affords the Navy the opportunity to quickly switch to new payloads as Fleet demands or experimentation results warrant. Admiral Richardson and other acquisition leaders have repeatedly  said that now is the time for the Navy  to take calculated risks, and while some developments may work and others may fail, the Navy needs that knowledge to move ahead. The Snakehead effort is attempting to push innovation at the speed the Fleet is demanding.

PMS 406 is also leveraging the standard request for information process in new ways to assess the technical and manufacturing base, gauge its experience level and capabilities, and gain insights from industry. Phase I LDUUV efforts will procure subsystems, sensors, and materiel from numerous vendors across multiple states. The Government is leveraging various contract mechanisms to reach dozens of industry partners for follow-on LDUUV phases and its family of UUVs, including the National Armaments Consortium Other Transaction Authority and a Naval Undersea Warfare Center Newport multi-award, indefinite delivery indefinite quantity contract.

The current operational focus for  Phase I will be on Intelligence Preparation of the Operational Environment (IPOE). Extensive use of the set-based design approach has proven valuable in determining  the relevance of this early mission set for Snakehead LDUUV. Set-based design brings the Fleet, requirements, and acquisition officials together at the onset of a program to speed up the process, and it allows the right decision to be made up front rather than having each of the entities making decisions in a traditional stove-piped process. This approach will also be used to help determine mission priorities for follow-on phases of the Snakehead program.


In September 2017, the Navy awarded two contracts for the Orca XLUUV for Phase 1 design efforts. Lockheed Martin was awarded a $43 million contract, while Boeing, teamed with Huntington Ingalls, was awarded a
$42 million contract. This significant milestone achievement provides a vivid demonstration of the fast-track acquisition strategy being employed by PMS 406 to accelerate this capability to the Fleet. These contract awards were preceded by a request for proposal (RFP) built off of a draft RFP released in November 2016 and an industry day that the Navy conducted in January 2017, where more than 50 potential industry partners attended. The final RFP for Orca was released in March 2017, with proposal responses received from industry at the end of May. The PMS 406 team worked hard to partner with industry to ensure the rapid contract documents were reviewed  and industry feedback incorporated.

The Orca program is a Navy accelerated acquisition effort serving as the Navy’s XLUUV class effort and is in response to a Joint Emergent Operational Need. This vehicle will help extend the range of current platforms to undertake specific maritime missions and can be launched from pier side or platforms at sea. Orca’s modular design will enable the UUV to deploy multiple types of payloads. Key performance attributes include extended vehicle range and persistence, a reconfigurable payload bay, modular construction, autonomy, and pier-launch capability.

With the awarding of the Phase 1 contracts, the two contractors will conduct detailed design efforts over the the next 15 months. (Both the Lockheed Martin and Boeing design concepts are pictured in Figure 4.) Once the design phase is completed, a single contractor’s design will be selected to build up to five vehicles, with the first XLUUV delivered in 2020, followed by two additional vehicles in 2021 and two in 2022.

Figure 4: Orca XLUUV Phase 1 Concept Renderings (Source: PEO LCS).




UISS is a 38.5-ft USV that will provide stand-off, long-endurance, semi-autonomous, minesweeping capability to counter acoustic and/or magnetic influence mine threats in the water column. UISS comprises a modular USV and an Influence Sweep payload, consisting of a magnetic sweep cable and a modified Mk-104 acoustic generator. The craft’s payload bay provides an opportunity to use different payloads in the future as missions and technologies evolve. UISS can be operated from VOOs, including LCS ships, or from shore. The system is being developed by Textron Systems Unmanned Systems Division.

A UISS Engineering Development Model craft initiated contractor testing in January 2017 and has accumulated more than 350 hr of progressively more strenuous in-water testing at Navy ranges in Florida. The test vehicle has achieved impressive in-water speeds at sustained levels of endurance. The USV has been controlled/operated from a land-based control station built as a surrogate of the LCS Command Center during these tests. Contractor testing will continue through the remainder of this year, with the system expected to transition to Navy developmental and operational testing in 2018.

MCM USV + Minehunting

The same UISS craft, the MCM USV, is a 38.5-ft craft with a 20-ft-long modular payload bay capable of employing multiple payloads. In addition to the influence sweep payload, the Navy is integrating both the AN/AQS-20 and AN/AQS-24 towed minehunting sonars with the MCM USV. The MCM USV + Minehunting payloads will provide the Navy with rapid, wide-area minehunting capability. Textron is currently building two MCM USVs to support the minehunting mission, Raytheon is developing and building a deploy-and-retrieve rig for the AN/AQS-20 sonar, and Northrop Grumman is developing and building a launch-and-recovery system for the AN/AQS-24 sonar. System testing will commence in late 2018 and will lead into a User Operational Evaluation System assessment period in 2019.


Starting in 2014, four MHUs have  been built and delivered to the 5th  Fleet Operating Environment in response to a Fleet Urgent Operational Need. The MHUs consist of an unmanned 11-m RHIB deploying an AN/AQS-24 towed minehunting sonar to conduct volume and bottom mine searches. The MHUs are maintained and sustained in the Arabian Gulf  area and continue to support numerous 5th Fleet exercises. Most recently, the MHUs were deployed aboard USS Lewis B. Puller (ESB-3), the first of the Navy’s new class of Expeditionary Mobile Base ships. These systems provide much needed additional minehunting capacity, augmenting the MH-53E helicopter capability.

Ghost Fleet

Funded by the Pentagon’s SCO, Ghost Fleet is an FY18 initiative that seeks to push the current technical limitations on USVs and UUVs to determine how these vehicles can boost the operational effectiveness of the Navy’s manned  fleet of warships.

The demonstration program consists of two distinct elements. First is the undersea component, called Undertaker. This element of Ghost Fleet was awarded to Boeing for analysis and testing of the Echo Voyager system
to inform a prototype build (a design concept of which is pictured in Figure 5) in the future.

Figure 5: Design Concept of the Undertaker (Source: PEO LCS).


The second element is called Overlord and seeks to develop and demonstrate the capability for larger USVs to independently deploy. A draft RFP was issued to industry for Overlord in September, and an industry day was held in October to solicit industry interest in the effort. What sets the Overlord effort apart from other USVs is the intent to convert larger, existing, manned ships into USVs over the next  3 years so that they can conduct existing missions now undertaken by manned warships. The operational goals for Overlord are USVs capable of conducting 90-day missions at sea with zero crew. The USVs will be outfitted for optional manning and constructed to conduct testing of a variety of payloads, including electronic warfare, surface warfare, and strike warfare.


By all accounts, the role of unmanned systems in military operations — as well  as in the Navy’s strategic vision — is one that is only expected to increase as these systems become smarter, more accessible, and more effective. Thus, it will be increasingly important for all stakeholders involved in the planning, research, development, and acquisition of these systems to maintain awareness, alignment, and communication in this important field.

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