News from a Distant Galaxy: Modular Systems for Unmanned Ships
USV Ranger and USV Mariner, somewhere in the ocean, 2023
We periodically criticize the idea of modular systems weapons, and in the neighboring galaxy, it seems, they are in no hurry to give up this opportunity. Here is what The War Zone and its author Joseph Trevithick wrote about this on July 31. True, there are links to other materials every now and then, so I had to digress, go wide and deep, and as a result, I got what can be called "based on".
It’s becoming increasingly clear that the Navy’s new plans for its family of USVs (unmanned surface vessels) are more focused on modular payloads in containers than on specific hull designs. The unmanned vessels, acquired under a program now called Modular Surface Attack Craft, or MASC (I’ll call them modular UAS from now on, to avoid anglicisms), can be configured to perform a wide range of missions, including surveillance and deterrence against friendly forces, and long-range strikes.
Earlier this week (article published July 31), the US Naval Sea Systems Command (NAVSEA) posted notice of contract conclusion, which set out requirements for three types of unmanned ships.
The budget request for next year mentions BECs very briefly in the section “Research and Development/Robotics, autonomous systems, surface”:
“The R&D effort includes $203 million in small, medium, and large unmanned surface vehicles. The Small Unmanned Surface Vehicle (SUSV) is a low-cost maritime mobility vehicle that leverages commercial technologies and innovations quickly and at scale. The Medium Unmanned Surface Vehicle (MUSV) is a low-cost, durable, reconfigurable vessel that can accommodate a variety of payloads and augment the manned surface force. The Large Unmanned Surface Vehicle (LUSV) is a high-availability, high-capability, and complementary surface force.”
(Then they ask for 688 million for autonomous underwater vehicles, but that’s another story. story.)
More details about the modular UAVs are included in the Navy's fiscal year 2026 budget request, which was submitted in June (the budget request for the entire Navy is $292 billion locally). And back in January, it was announced that after years of experimenting with two different categories of large and medium-sized unmanned vessels, plans for the UAVs had changed.
Previously, the Navy classified UAVs by size: Large Unmanned Vessels (LUSVs) were defined as being up to 300 feet in length and displacing up to 2000 tons, while Medium Unmanned Vessels (MUSVs) were defined as being under 200 feet in length and displacing under 500 tons. The Navy is also pursuing development of smaller unmanned vessels such as speedboats and jet skis (i.e., a planing craft with a jet drive) and appears to intend to continue to do so separately from the modular UAVs.
Note: 1. The high-speed unmanned boat, or drone boat, produced by L3Harris, was shown on the dvidshub website back in August 2023. The photo shows the general transport vessel USNS Amelia Earhart, the destroyer USS Thomas Hudner, the Coast Guard ship USCGC Charles Moulthrop and the same drone boat with the number 55 and the name Arabian Fox, passing through the Strait of Hormuz.
By this time, the BEF had been in the Gulf for several months, based in Bahrain and carrying out reconnaissance missions along the route of warships. The BEF reportedly operated in a “semi-autonomous” mode, had a collision avoidance system that allowed it to operate in close cooperation with other vessels, and could reach speeds in excess of 40 knots.
Note 2: The jet skis first appeared in the Navy's fiscal 2024 solicitation. No details were provided, but the prototype would be based on Black Sea Technologies' Greenough Advanced Rescue Craft (GARC) design.
The boat is 4,5 m long, 1,8 m wide, has a speed of 35 knots and a payload of 350 kg. The diesel engine and fuel supply allow for a range of 700 miles at 6 knots and 300 miles at 30 knots. The Navy will try to adapt the boat as a platform for light weapons: a .50-caliber machine gun, a 40-mm automatic grenade launcher, a 3-barrel machine gun with a rotating barrel block GAU-19, and also use from the boat missiles Hellfire and AGM-176 Griffin.
The NAVSEA notice for the modular UAV program calls for three design options: a basic version, a heavy-lift vessel, and a single-payload vessel. The vessel requirements are based on payload capacity, range, and speed, but not on size and/or displacement.
"The basic configuration of the vessel must carry at least two forty-foot equivalent containers, each with a payload of 36,3 metric tons and consuming up to 75 kilowatts (kW) of power. With 25 tons of cargo on deck, the vessel must have a minimum cruising range of 2500 nautical miles, maintaining a sustained speed of at least 25 knots in accordance with NATO Sea State 4."
According to NATO standards, Sea State 4 is characterized by wind speeds of 17 to 21 knots and wave heights of 1,2 to 2,5 meters.
Naval fleet also aims to meet the need for a high-performance platform for handling payloads that are integrated into ISO standard containers. The desired vessel should be capable of carrying at least four 40-foot FEU containers with a payload of 36,3 tons each and a power consumption of up to 50 kW each. The technological solution should provide the maximum cruising range as far as is practicable.”
USV Ranger with containers on board. What's in there?
The following describes another type of modular UAV with a single payload unit, which must be able to carry at least one 20-foot container (TEU) with a payload of 24,0 tons and a power consumption of up to 75 kW. The container must have no obstructions on the way from its installation to the transom (i.e. the stern). And again: "The technological solution must maximize the speed and the cruising area as far as is practically possible."
Notably, there is a specific reference to power generation requirements in all three cases. Even when it comes to traditional manned warships, onboard power capacity is often a key limiting factor in the adoption of new technologies. For the modular UAV program, this should be especially true when it comes to any future plans to equip unmanned ships with laser or high-power microwave directed energy weapons, as well as electronic warfare suites.
The notice also lists additional "highly desirable," "strongly desirable," and "other desirable" characteristics that apply more broadly.
The “highly desirable” category, for example, includes “the ability to autonomously and safely avoid hazards at sea and collisions with vessels, including in low visibility conditions and in situations where radio frequency emissions are prohibited.” “The vessel must be able to safely continue the mission if contact with the control station is lost. These manoeuvres must comply with COLREGS (International Regulations for Preventing Collisions at Sea) requirements, and the vessel must autonomously classify contacts in accordance with COLREGS.”
NAVSEA also says it is highly desirable for contractors to be able to quickly build modular UAVs of any design, preferably in less than 18 months from the initial contract award.
For unmanned modular UAVs with performance exceeding threshold requirements, the list of “strongly desired” capabilities includes the ability to operate in sea state level 5 conditions (winds between 22 and 27 knots and waves between 2,5 and 4 meters). This category also includes the ability to “automatically adjust the radio frequency emission depending on the mission requirements transmitted to the platform via the onboard control station.”
According to NAVSEA, it is best to build ships to commercial standards that can be easily repaired and maintained. The Navy is also interested in ships that can “operate for extended periods without preventive maintenance, corrective maintenance, emergency repairs, or any other form of repair or maintenance.”
The list of “other desirable” features includes designs that could be offered for export to allies and partners, as well as basic vessel types with accommodations for up to eight people for up to 14 days. It’s worth noting that to date, all of the medium and large UAVs the Navy is experimenting with have additional crew, and it’s unclear whether the service is interested in fully unmanned versions of the modular UAVs.
The contract award notice does not outline any requirements for specific payload types. Navy officials have previously said that initial plans for the new UAV concept include weapons payloads originally envisioned for use on future large UAVs, as well as intelligence, surveillance, and reconnaissance (ISR) systems developed under previous medium UAV designs.
Note 3: The payload in question is almost certainly the Mk 70 Expeditionary Launcher, which does not yet seem to have a specific name and is known as the Payload Delivery System or Container Launch System.
Mk-70 on the deck of USS Tulsa, exercise RIMPAC-2022
Mk-70 on exercise in Denmark, 2023
Mk-70s being unloaded from a cargo plane, Bornholm airfield, 2023
These are four Mk 41 Vertical Launch System cells housed in a 40-foot container. From there, they are capable of launching a variety of missiles, including the Standard Missile-6 (SM-6) and Tomahawks. Back in 2021, the Navy announced that it had test-fired an SM-6 from a Mk 70 mounted on the experimental Ranger unmanned combat ship. The Navy also plans to use the Mk 70 as a firepower enhancement for its two classes of Littoral Combat Ships (LCS), as well as in a land-based configuration.
The ability to accommodate other types of payloads will likely carry over to future U.S. Navy unmanned ships. The War Zone previously described the possibility of adding containerized launchers to deploy swarms of UAVs to manned surface ships, and these capabilities will also be relevant to future modular UAVs.
It is also worth noting here that the Navy's current experimental medium unmanned submarines, the Sea Hunter and Seahawk, were created as part of a program aimed at finding and tracking enemy submarines using fixed and towed sonars. The ISR systems installed on the unmanned submarines, as well as the means to help counter enemy ISR capabilities, may include a variety of other sensors, as well as electronic warfare.
In addition to previous efforts regarding average BECs:
“MASC will support the Navy’s ability to generate, field, and employ ISR&T/C-ISR&T/IO (the military loves acronyms, so this would stand for Intelligence, Surveillance, Reconnaissance/Targeting and Countermeasures; IO stands for Information Operations) capabilities in sufficient numbers and provide/enhance distributed situational awareness across maritime areas of responsibility,” the budget request says. “These UACs will be capable of multi-week deployments and transoceanic transits and will be able to operate as part of carrier strike groups, surface strike groups, or independently. These UACs will be a key element of the Distributed Maritime Operations concept.”
The large UAV line item in the proposed FY 2026 budget does not provide similarly clear guidance on the transition to modular UAVs. In the past, the Navy has considered large UAVs for long-range strike missions.
The FY 2026 budget proposal outlines plans to continue to use existing experimental designs as the primary source for a new modular UAC program. An experimental medium UAC-class ship named Defiant, developed under the Defense Advanced Research Projects Agency’s (DARPA) “Unmanned Ship” program, would be delivered to the Navy in the next fiscal cycle. Defiant largely meets both the Navy’s currently stated baseline requirement for a medium UAC and the requirements for the company that will design and build the ship, Secro, and it is already working on a scaled-up version of the unmanned ship.
Defiant in the outfitting shed
Defiant at the shipyard berth
And in this form, the ship was spotted in March 2025 near Seattle, where the Whidbey Island air base is located, which nevertheless belongs to the Navy.
Note 4: USX-1 Defiant was designed from the outset as a medium-sized unmanned vessel suitable for mass production. Launched in March 2025, it is 55 meters long and displaces 240 tons. The Defense Advanced Research Projects Agency (DARPA) wanted a vessel like this to be able to operate in the ocean for a year without any human intervention, be easy and cheap to maintain, and be able to reach speeds of up to 20 knots in sea state category 3 (see above).
The ship is being built by Serco, which Wiki says is a “British multinational in the fields of defence, healthcare, space, justice, migration, customer service and transport” – well, apparently it also builds ships. According to the company’s managers, the cost of the Defiant without additional systems and equipment will be 25 million dollars. They also say that to build the ship, it is quite sufficient to have something like a railcar repair plant on hand, and not necessarily a traditional shipyard. The ship has a flat deck behind and in front of the wheelhouse, where standard containers can be conveniently placed. Serco also showed that it can also accommodate what BAE Systems calls an Adaptable Deck Launching System (ADL) – this is a thing like this.
There are four tubes hidden from the VLS-41 vertical launch system, so any combination of weapons suitable for this system can be used. But the initial intention is to use the Defiant to demonstrate the ability to remain at sea for long periods without maintenance.
It is unclear at this time when the modular UAVs might begin to enter service and in what configurations. “In FY 2026, the modular UAV program will work with industry to identify prototypes, refine technologies, and demonstrate UAV capabilities,” Navy budget documents say.
It appears that UAVs have long been viewed by navies as a key way to bolster their surface fleet. Distributed groups of UAVs, capable of attack and reconnaissance operations, capable of operating independently or in groups, as well as in conjunction with manned combat ships, offer new operational opportunities. UAVs can also help reduce risks to manned vessels. Modular designs that can be easily configured and reconfigured for different missions using containerized payloads will also pose challenges to adversaries.
"What's in that box, weapons or other cargo? We've got to keep them guessing," said Rear Adm. William Daly, chief of the Surface Warfare Division, while discussing the new U.S. Navy vessel at the Surface Navy Association's annual symposium. It's unclear how.
The troubling and widening gap in shipbuilding capacity between the United States and its main global rival, China, has also put a new spin on BECs. The U.S. government has been trying to reverse that trend in recent years, including exploring the potential of bringing in foreign shipyards to build more crewed combat ships. At the same time, the Navy’s traditional shipbuilding programs continue to be plagued by delays and rising costs, and are generally expensive and require long build times.
NAVSEA’s stated interest in rapidly-producible UAV designs built to commercial standards could provide additional benefits. The contract award notice also leaves the door open for foreign participation in the construction of modular UAVs or related projects, which could further accelerate development and reduce costs. Collaboration on unmanned capabilities, including in the naval domain, is already a key aspect of the Trilateral Defence Cooperation Agreement between Australia, the United Kingdom and the United States. Last year, Australia announced plans for significant new investment in larger UAVs.
Overall, it is clear that the Navy is now looking at modular UAVs as a way to finally begin using larger Drones after many years of seemingly endless experiments.
This article ends.
A little history
In 2018, the US Defense Strategic Research Office initiated the Ghost Fleet Overlord program, which was carried out in close cooperation with the Navy. The most famous vessels participating in the program were Ranger, Nomad, and Mariner, which were later joined by Vanguard. All four “served” in a specially created unit USVDIV-1 and bore tactical numbers OUSV-1,2,3,4, and so on. These four served as a test platform and technology demonstrator. In addition, there are two smaller and lesser-known vessels, Seahawk and Sea Hunter. All four were different in some way: different hulls, different electromechanical equipment, and were tested for different tasks with different equipment. All of them participated in exercises, repeatedly crossed the ocean independently or in a group of ships, and some even passed through the Panama Canal - albeit with “limited intervention” of the crew.
The very first one was
Ranger, IMO 9842231
Originally built as a platform supply vessel, it was later purchased by the Navy and converted to the needs of the military program - that is, everything was done on the principle of "use commercial designs". Most likely, the change of hands occurred at the slipway, and the new vessel was immediately named Ranger. According to the IMO number, you can find out that at the moment the ship is at the berth in the port of Hueneme - this is between Los Angeles and Santa Barbara. The US Navy has about a mile of berths and related facilities in this port, and, apparently, it is a base for experimental BECs. At least, marinetraffic often shows that one of them is in this port.
The USV Ranger is known for launching the SM-6 multi-purpose missile using a "container-type launch pad." In 2020, it transited the Panama Canal with a skeleton crew "for safety," but was controlled from Surface Development Squadron 1.
Nomad, IMO 9759379
The second vessel to join the Ghost Fleet program, built in 2014 by Swiftships as an offshore patrol vessel and originally named Riley Claire.
The Navy acquired it in the late 2010s. In 2020, it sailed from the Gulf of Mexico to the West Coast and also through the Panama Canal, covering a total of 4400 miles. The Navy said the ship was in “unmanned mode” 98 percent of the time.
It should be said that all these ships had cabins and all the necessary rooms for 5-8 people from the moment of construction, and the Navy did not remove them during the remodeling. The press periodically mentions that the crew was present during the voyages, but did not interfere with the management.
Mariner, IMO 9916068
It was purchased at 50% completion directly from the Gulf Craft shipyard in the small town of Franklin, Louisiana, where it was again built as an oil platform supply vessel, and joined the Ghost Fleet program in 2022. Its dimensions are 49 x 10 meters. The draft is 2 meters. The power plant consists of five diesel engines with a capacity of 2000 hp, each supposedly working on its own water jet. There is a bow thruster.
The Navy added another diesel generator, outfitted the ship with a state-of-the-art control system that allows it to act as a mother ship for other UBCs, and installed some of the Aegis hardware that allows it to interface with other ships with the same system. The cargo deck can accommodate eight 20-foot containers or four 40-foot containers (are those boxes weapons or something else?).
In late 2023, a pair of UAVs demonstrated an unmanned fueling system at sea, with Mariner (pictured right) fueling Ranger. The CFAS (Crewless Fueling at Sea) program was initiated by the DARPA Advanced Research Projects Agency.
Both ships had a small crew on board, just in case. Information provided by DARPA says that personnel from the "receiving vessel" were not involved in the process.
In September 2023, during joint exercises with the Japanese Navy, in which the US Navy also included Mariner and Ranger.
USVs Ranger and Mariner alongside Japanese Mogami-class frigate
Two “drones” visited the port of Yokosuka – although it is not known whether they were in “manned” or “unmanned” mode. Local amateur observers caught them entering the American sector of the port. They noted that both vessels appeared to be “heavily loaded” with containers, the Mariner had an extra mast and a second radar on its stern, and the Ranger had a crew of at least three people.
Mariner is currently in the same port as Ranger.
Vanguard
This is the first ship that was built specifically for the Navy as a fully autonomous vessel.
It is reported that it was built by Austal USA in cooperation with L3Harris at the shipyard in Mobile, Alabama, and was built to commercial standards. After completing the tests, it should autonomously move to San Diego, that is, go through the Panama Canal. Well, of course, if the route around South America is not chosen. =)) Based on its length of 205 feet, it belongs to the "large BEC" class. Although it is unknown whether its displacement corresponds to this class. Launched in 2024, but apparently not yet delivered to the customer. Judging by the photo, the shape of its hull is very different from the previous four. No News There is no news about it yet, marinetraffic does not track it, and it looks like this is the only image of it available.
Sea Hunter and Seahawk
Two identical ships (well, almost), built by Leidos for the Naval Research Department.
The first was built in 2016 for 22 million, the second in 2021 for 35 million. The Seahawk design, according to statements, has about 300 changes made as a result of the operation of the Sea Hunter. They are distinguished by a long narrow hull made of composite and two outriggers on the sides - that is, this is what is called a "trimaran". They are 40 m long, have a displacement of 145 tons, have two diesel engines of unknown power and two propellers.
The maximum speed obtained during testing is 27 knots. The estimated duration of continuous stay at sea in autonomous mode is 90 days, the cruising range is 10000 miles at a speed of 12 knots. They must function normally in sea state 5 according to NATO standards and "survive" in sea state 7 - this is already a wave of 6 meters and a wind of 35 knots.
The vessel has facilities for necessary maintenance, but no facilities for "permanent occupancy." Program manager Scott Littlefield said in an interview at the launch that "the ship is computer-controlled, but a human is constantly watching and can intervene if necessary" - whatever that means. The vessel will have a removable deckhouse for the duration of the tests, and there will be someone on board at all times.
It has no weapons of its own. The daily operating cost varies from 15 to 20 thousand money, compared to 700 thousand for a destroyer. Both unmanned submarines are participating in the "anti-submarine warfare long-term test for unmanned vessels", or ASW ACTUV, but have already performed other tasks. For example, Sea Hunter, immediately after its construction in 2016, tested the idea of a paraglider equipped with a set of reconnaissance sensors (the TALONS program).
In 2017, during exercise Warrior 2017, this UAC, along with the aircraft carrier Theodore Roosevelt, the cruiser Bunker Hill, three Arleigh Burke-class destroyers and the submarine Pasadena, had on board an experimental long-range laser communications station, with the help of which it transmitted more than 10 GB of digital data, video and voice messages in a single session.
Sea Hunter or its sister ship enters port:
And when zoomed in, you can see the figure of a man in the center of the wheelhouse, clearly participating in the process:
In 2022, the Ghost Fleet program was closed, apparently the military found out everything they wanted. The ships were handed over to the Navy, where they entered the specially created USV Division 1, where they continue to be used. As for Nomad, all secrets were removed from it and unexpectedly put up for auction, without giving a reason. For 2,2 million, it was bought by Curtin Maritime and turned into a fast crew boat - that is, a vessel for delivering personnel to offshore platforms.
Now it is called Blair C. From the brochure you can see that it has an aluminum hull measuring 52 x 9 m, a draft of 1,8 m, a speed of 30 knots in maximum mode and 18 in economy mode, a crew of 4-6 people, and it can take 70 passengers. There are three diesel generators of 200 kW and four main engines Cummins with a capacity of 1800 hp each, and the propulsion is a water jet. Naturally, all the necessary radio navigation equipment is available and even a dynamic positioning system of class 2. With the help of the auction sheet, you can admire some of the premises:
That's it now. As we can see, the gloomy extragalactic genius does not sleep and generates ideas. And these ideas work, float, shoot - in general, are tested in hardware.
Information