Navy's Sea Hunter Drone Ship Has Sailed Autonomously To Hawaii And Back Amid Talk Of New Roles

The service is now looking at using the unmanned ships as electronic warfare platforms to blind and distract opponents.

DARPA

The U.S. Navy’s Sea Hunter unmanned surface vessel has become the first ship of any description to ever sail from San Diego, California to Pearl Harbor, Hawaii and back without the need of a crew for navigation and steering. It’s a significant milestone for this particular vessel and its future cousins, which the service has primarily been developing as anti-submarine warfare platforms, but could also provide electronic warfare support and acting as decoys to help shield friendly forces.

Defense contractor Leidos, which is leading the Sea Hunter project for the Navy, announced the achievement in a press release on Jan. 31, 2019. The notice did not say when the trimaran craft, formally known as the Medium Displacement Unmanned Surface Vehicle (MDUSV), had left from or returned to San Diego, a round trip of more than 5,200 miles. Previous reports noted that the vessel had first arrived at Pearl Harbor on Oct. 31, 2018.

“The Sea Hunter program is leading the world in unmanned, fully autonomous naval ship design and production,” Gerry Fasano, Leidos Defense Group President, said in the press release. “The recent long-range mission is the first of its kind and demonstrates to the U.S. Navy that autonomy technology is ready to move from the developmental and experimental stages to advanced mission testing.”

The MDUSV did have a manned escort throughout the voyages. Personnel did board Sea Hunter at times to check the ship’s electronics and propulsion system, but Leidos did not say whether or not any repairs were necessary during any of the transits.

USN

Sea Hunter in Hawaii in October 2018.

In 2016, Oregon Iron Works, now called Vigor Works, built Sea Hunter for the Defense Advanced Research Projects Agency (DARPA), which initially called it the Anti-submarine warfare Continuous Trail Unmanned Vessel (ACTUV). In January 2018, DARPA turned the vessel over to the Office of Naval Research.

Leidos originally built the navigation system for the vessel, but has now taken over responsibility for the entire program. The Virginia-headquartered firm is now on contract to build a second MDUSV, known tentatively as Sea Hunter II.

The Navy is still developing its plans for how might employ these unmanned vessels in the future. In an interview with Breaking Defense on the sidelines of the annual Surface Navy Association’s main annual conference in January 2019, U.S. Navy Rear Admiral John Neagley, the service’s Program Executive Officer for Unmanned & Small Combatants, offered some new details about the roles and missions for the future MDUSVs.

“Part of the value of having unmanned surface vehicles is you can get capacity at a lower cost,” he explained to Breaking Defense. As it stands now, the Navy is primarily looking to use the Sea Hunters, or similarly sized unmanned vessels, as scouts and decoys, packed with sensors and electronic warfare systems as part of a concept the service is calling “Electromagnetic Maneuver Warfare.”

DARPA

Sea Hunter prior to its formal transfer from DARPA to the Navy.

A group of MDUSVs, networked together with each other and manned ship, and operating autonomously, could cover a much broader area looking for all sorts of potential threats, including enemy surface ships and submarines, mines, or shore-based defenses. The unmanned vessels could use electronic warfare systems to blind enemy radars and other sensors or employ electronic support measures to geolocate and classify those targets, helping commanders get a better sense of an opponent’s “electronic order of battle.”

This, in turn, would provide important situational awareness and give manned ships additional options to avoid threats or launch strikes from the most optimum direction. A screen of Sea Hunters could make it more difficult for hostile submarines or other pop-up threats to get the drop on high-value vessels, such as aircraft carriers and amphibious assault ships.

MDUSVs would also be to act as decoys, generating electronic signals similar to larger ships and giving the appearance of a large, distributed attack, confusing an enemy or otherwise forcing them to spread their forces thin across a wide area. All of this could be particularly valuable in the open expanses of the Pacific region.

All of these concepts of operation benefit from Sea Hunter’s range and endurance capabilities, as well as plans for it to be able to operate completely autonomously. That the ship was able to navigate from California, out into the Eastern Pacific, and safely make it to Hawaii, as well as perform the return trip, all point to the increasing maturity of the vessel and its critical systems.

Those same attributes mean that Sea Hunter, or follow-on designs, will remain capable of wide-area, persistent missions more independent of manned ships, as well. DARPA has originally explored using the unmanned ships for anti-submarine and mine-sweeping missions.

In the anti-submarine role, Sea Hunter and its future cousins would offer cost-effective options for monitoring submarine activity across a wide area and be able to persistently track those threats. With that information, commanders would have better situational awareness and could then direct manned aircraft or surface vessels to engage those targets or look to avoid them altogether during a crisis.

The unmanned vessels would provide a valuable, lower-risk alternative for mine-hunting and clearing operations. The smaller MDUSVs would have the ability to more readily maneuver, especially in narrow waterways, to find and neutralize underwater hazards and do so without putting sailors at risk.

Sea Hunters, or similar unmanned ships in this size class, might eventually take on other roles, too. You can read more in detail about how the MDUSVs might operate in the future, here.

The Navy is also developing requirements for even larger unmanned surface vessels, which will leverage the lessons learned from Sea Hunter, but will be able to take on another new set of missions. So far, the service is primarily envisioning these Large Displacement Unmanned Surface Vessels (LDUSV) as "arsenal ships," linked together with various manned and unmanned platforms through the Cooperative Engagement Capability (CEC) network concept. 

Other ships, including the Navy's future guided missile frigate, or FFG(X), as well as manned and unmanned aircraft, could provide targeting information for those crewless arsenal ships. As such, they may not even need to carry their own sensors, allowing for more space to be devoted to stand-off weapons. 

When it comes to Sea Hunter, more specifically, it “is a ship that you just sit down over the horizon and it might be able to do an awful lot of things that you don’t want a manned platform to do, especially in an area where there’s a lot of anti-access, area-denial threats,” then-Deputy Defense Secretary Bob Work said in 2016 at the vessel’s christening ceremony. “The U.S. military has talked about the strategic importance of replacing ‘king’ and ‘queen’ pieces on the maritime chessboard with lots of ‘pawns,’ and [this] is a first step toward doing exactly that.”

Medium, as well as large unmanned surface vessels,  are also becoming increasingly important to the Navy's future plans to increase the total number of hulls available for combat missions. Sea Hunters and other future designs could potentially provide a cost-effective way for the service to finally reach its long-held goal of a surface force with 355 ships.

But whatever roles unmanned surface vessels, takes on in the end, Sea Hunter's recent long-distance trips are significant achievements and are major steps for the Navy toward adding larger and more capable unmanned vessels into routine operations.  

Contact the author: jtrevithickpr@gmail.com