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By Kris Osborn - Warrior Maven

(Washington, D.C.) A coordinated fleet of Navy drone boats could test and penetrate enemy defenses, launch forward-operating attacks across large areas of ocean, clear mines, attack submarines and use emerging AI to rapidly adjust to changing war circumstances.

Perhaps of utmost significance, a large fleet of integrated surface and undersea drones can network to one another, massively expanding the reach and effectiveness of sensors, weapons and air-sea coordination. This kind of desired tactical advantage forms the basis for the Navy’s Ghost Fleet Overlord project, a multi-year technical initiative to engineer a “fleet” of coordinated unmanned systems, intended to give warzone decision-makers crucial combat sensitive information amid life-threatening, dangerous exchanges of fire.

It is within this war context that the Navy is accelerating as many as seven new prototype Unmanned Surface Vessels (USV) to the fleet over just the next few years.

The now on-the-way drones include two large submarine-hunting Sea Hunter drones, four vessels designed to support Overlord and one new Medium USV, Navy weapons developers said.

“The reason we need these vessels is to demonstrate a number of different autonomy technologies and a variety of different payloads envisioned. We also need to match fleet CONOPs (Concepts of Operations) that employ multiple USVs operating in proximity with each other,” Capt. Pete Small, Unmanned Systems Program Manager, Naval Sea Systems Command, said in a presentation at the 32nd annual Surface Navy Association Symposium, Arlington, Va.

The seven prototypes, slated to arrive over the next few years, are part of a broad Navy effort to add large numbers of surface and undersea drones to the fleet -- quickly.

“We will also need them (the prototypes) to develop the thousands of hours of water time and testing we will need to develop autonomous behavior of these vessels,” Small said.

Development of the new Ghost Fleet Overlord drones has been a multi-year project involving the Office of Naval Research, Naval Sea Systems Command and DARPA, the Pentagon’s research arm. Autonomy and human-led command and control systems form the basis of the evolving technical progress, which is woven into an existing Navy program called Unmanned Maritime Autonomy Architecture (UMAA), Small said. The service is now working on new technically detailed Interface Control Documents, intended to bring this vision to fruition.

“Overlord is command and control that we envision operating on all of our USVs,” Small said.

While preparing to arm the maritime drones with weapons, Small explained that the initial focus for the new, larger surface drones will be autonomy, endurance, precision navigation and command-and-control. Of greatest significance, Small explained, is that the prospect of large numbers of interwoven, armed surface drones introduced an entirely new sphere of Tactics, Techniques and Procedures. These surface drones, operating in tandem with surface ships, undersea drones, aerial drones and submarines, promise to change the character of maritime warfare. USVs could help foster an impactful cross-domain tactical option which linked air, surface and undersea assets into an integrated command and control network. Small said that developmental USV interface documents were focused on continued efforts to engineer a common control system able to connect Naval Sea Systems Command with Naval Air Systems Command.

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Textron Systems photo - Common Unmanned Surface Vessel

A fast growing fleet of USVs, it would appear, could bring the promise of greater forward-deployed command and control, along with an increased ability to integrate a range of otherwise separated functions. For instance, it seems entirely plausible that a new MUSV could combine submarine hunting with mine-countermeasures, command and control and surface attack. As a forward positioned vessel, it could enable deeper draft manned ships to operate at safer standoff ranges. Also, by pushing the limits of technology, larger surface drones could potentially bring unprecedented amounts of endurance. Not only would they not need to constrain mission dwell time by a need to return human crews, but larger drones could potentially carry more fuel, supplies and ammunition.These missions also include things like perimeter security, wherein unmanned armed surface vessels are forward-deployed to identify and attack approaching targets, all while protecting larger ships such as Littoral Combat Ships or even Carrier Strike Groups and Amphibious Ready Groups.

While the initial priorities for Ghost Fleet involve coordinated ISR, targeting and AI-enabled autonomous operations, the Navy is also now exploring the possibility of adding weapons to the USVs. Naturally weapons specifics regarding ongoing testing might not be available for security reasons, there are a number of potential weapons combinations which might seem suitable for USVs. The nearest-term applications might likely involve smaller, mobile attack weapons such as .50-cal machine guns, 57mm guns or other standard deck-fired weapons or even MANPAD types of heat-seeking anti-air and surface warfare attack weapons. While an unmanned ship is certainly less likely to have Vertical Launch Systems for large interceptor missiles, it seems possible that smaller weapons and various deck-mounted systems could easily integrate onto a medium- or large-sized surface drone. However, configuring a large surface drone to fire torpedoes might fall within the realm of the possible. This kind of weapons range, to include the possibility of interceptors, various gun systems and some small remotely-fired missiles, could target enemy drones, lower-flying aircraft, attacking small boats and enemy ships at ranges otherwise more difficult to reach with ship-board sensors and weapons.

Some key elements of the value added by the Navy’s fast move to add more USVs seems to have been anticipated by a 2013 RAND study called “US Navy Employment Options for Unmanned Surface Vehicles.” As part of a detailed analysis of surface drone warfare, the RAND report seems to foreshadow what has emerged over the last five years. Among other things, the report sites Navy UVSs as having an autonomous ability to “counter fast attack craft.” The RAND study also specifies a number of specific combat advantages potentially provided by USVs, when compared to Unmanned Undersea Vehicles (UUVs) and aerial drones.

--USVs have greater potential payload capacity and endurance than comparably sized unmanned systems in other domains. They are able to use higher-density energy sources than UUVs (hydrocarbons instead of batteries), and, unlike UAVs, they do not need to burn fuel merely to maintain their vertical position; if desired, they can move relatively slowly for days or weeks without refueling. -- from the RAND study.

USVs could also potentially bring unprecedented electronic warfare possibilities; one of the key drawbacks when it comes to electronic attack is the risk of an attacker giving their location away by virtue of emitting a broad, detectable signal. For this reason, the military services have been working with industry to engineer more narrowly configured electronic attack signals. Given this challenge, having an unmanned system conduct EW missions lowers risks to sailors who might be endangered should a signal be located by an enemy.

In order to capitalize upon a built-in ability to house larger, more complex payloads, the Navy’s new USVs are, by design, being engineered with a set of common standards and defined interfaces to accommodate new weapons, software and technologies as they emerge. The strategy, using interoperable protocol and hardware architecture, can not only reduce the hardware footprint but help create the technical infrastructure necessary for continued modernization. In fact, within the context of this technical strategy, Small said the ICD is specifically oriented toward software modernization for Overlord. Small said UMAA will help upgrade autonomy, payloads command and control systems “without having to re-architect.”

Sea Hunter

Two of the seven drones on the way are large submarine-hunting Sea Hunter drones, platforms which have been developing for the last several years. More recently, the Navy has been expanding the mission scope of its submarine-hunting drone ship so that it can conduct surface warfare missions, fire weapons and launch electronic attacks.

The Defense Advanced Research Project Agency’s “Sea Hunter” began in 2010 as an anti-submarine ship called “Anti-Submarine Warfare Continuous Trail Unmanned Vessel,” or ACTUV.

The ship is built to travel up to 10,000 miles while using sonar and other sensors to locate mines and even the quietest enemy submarines. The Sea Hunter’s high-frequency sonar can send acoustic “pings” into the ocean before analyzing the return signal to determine the shape, size, speed and characteristics of any undersea enemy activity.

The 135-ton ship is engineered to withstand rough seas up to Sea State 5 – or waves up to 6.5 feet. The 132-foot drone uses advanced hydro-acoustics, pattern recognition and algorithms for unmanned navigation to locate and shadow diesel-electric enemy submarines.The idea is to track them, if necessary, over a period of months so they are compelled to stay away from strategically vital areas.The Pentagon’s research arm has also, in recent years, been extending testing of its sub-hunting drone able to travel autonomously for up to 90 days using sensors and sonar technology to search for enemy submarines and other airborne and undersea threats such as mines.Progress with the Sea Hunter has involved replacing a turret on top of the drone with a range of sensors for ISR, surface-oriented technologies, weapons and electronic warfare systems, Navy developers have said.

As technology has evolved in recent years, the Navy has been migrating the Sea Hunter’s operational scope from something that is tele-operated to something that can increasingly perform a wider range of functions without needing human intervention.


Osborn previously served at the Pentagon as a Highly Qualified Expert with the Office of the Assistant Secretary of the Army - Acquisition, Logistics& Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University.

--- Kris Osborn, Managing Editor ofWARRIORMAVEN (CLICK HERE) can be reached