Unmanned naval systems are rapidly reaching the limitations of physics with regard to their endurance. Current internal combustion and electrically powered systems have several drawbacks. In addition to range/weight issues, liquid fuel engines make for noisy UAVs which can compromise missions in some circumstances, such as intelligence, surveillance, and reconnaissance. Electrically-powered UAVs are quiet, but batteries do not approach the energy contained within a similar weight of fossil fuel. This article clearly explains the physical limitations of current battery technologies. Modern lithium-ion batteries are problematic due to their propensity to catch fire and explode. SOCOM’s billion dollar Advanced SEAL Delivery System (ASDS) fire illustrated why navies are not keen on carrying lithium-ion batteries at sea, especially undersea. Clearly, alternative power technologies are in high demand.
Previously, we highlighted the use of ship-based lasers to power future UAS. The video below discusses these tests, along with a propane-powered variant. Planned upcoming flight tests will demonstrate the ability to keep a Stalker Small Tactical UAS aloft using a laser for two to three days.
For long-endurance surface and underwater vehicles where speed is not a mission requirement, wave power and buoyancy-driven gliders are viable alternatives. Another possibility for powering future autonomous sea-floor crawlers or UUVs is the benthic microbial fuel cell. Naval drones will require continued innovations in power to allow performance necessary to meet future operational requirements.
Last winter over at Information Dissemination, I made the observation that swarming robots will irreversibly transform warfare, and I hold to that argument. The discussion and progress in this area is developing quickly. Much of this conversation involves non-military uses for drone technology, but as with many tools, there are also applications for warfare. A host of militarily useful scenarios can be envisioned to employ very small unmanned naval platforms in a non-lethal fashion.
In the videos below, quadrotors are used to perform simple construction tasks. The technology that is today viewed as modern performance art could some day be utilized to build an expeditionary forward operating base remotely. A C-130 would fly over a likely FOB site and deploy hundreds of UAVs, which would quickly go to work filling Hesco Barriers and building fighting positions all night long based on a pre-programmed design, a scoop of sand at a time. Out of power, the drones could then land on the FOB and relay observations to the incoming troops. The site would be defensible as soon as the first Marines arrived, leaving Sea Bees for more valuable construction projects.
Researchers in the UK are developing autonomous vehicles which will replace the tedious role of scuba divers who painstakingly seed damaged coral reefs. The alternative being worked is to allow “multiple small autonomous robots following a simple set of rules and seeking out coral fragments and re-cementing them to the reef. But first the robot needs to be driven by a computer ‘trained’ to recognise coral fragments from other objects such as rocks, litter, sponges and other sea creatures… The swarm of autonomous underwater robots will operate according to a simple set of ‘micro-rules’ to seek out coral fragments and re-cement them to the reef.”
A swarm of nano-UUVs similarly equipped as the “coralbots” could quietly infiltrate an enemy naval port and use sensors and algorithms to recognize seawater intakes on ships. These intakes are indispensable on just about every vessel and are used for heat exchangers cooling engines and various pumps, to make fresh water for the crew, and to propel water-jet equipped ships like the LCS. The UUVs could inject a combination of mud or sand scooped up from the harbor with epoxy into these intakes, effectively rendering the fleet useless and unable to get underway. A similar attack could gunk up the intakes to power plants, refineries, and other coastal infrastructure.
The idea of drones mimicking insects might have other applications. Like bees or fire ants who can subdue a much larger predator, disposable micro-UAVs – too small to defeat with CIWS or other weapons systems – might swarm an Aegis combatant, each spraying a tiny amount of radar absorbent paint on the SPY array, achieving a mission kill of the most powerful air and missile defense system in the world.
Of course, these sorts of aerial swarms might be vulnerable to jamming, EMP, and the like, but here, LT Matt Hipple offers some recommendations to build resiliency into drone swarms. The rapid evolution of drone swarm technology can be expected to continue until concepts like these are deployed operationally; likely sometime in the next decade.
After months of patient progress the drones reached their targets. Over the span of a few weeks they silently arrived at their pre-assigned loiter boxes (lobos) in the many harbors of Orangelandia. Having been launched from inconspicuous commercial vessels in major shipping lanes, the transit time was shortened by a good month. Yet for the few who knew of the operation, the anxious waiting was plenty long enough. The policy makers monitored the gliders’ headway via secure satellite datalinks and assured themselves that the operation, sold as a precautionary measure, was warranted in light of heightened tensions with Orangelandia.
As the weeks passed tensions only increase. Orangelandia declared its claimed EEZ closed to all foreign military vessels and threatened to sink any violators. After making good on its promise in a naval skirmish against a neighbor with rival claims to an island chain, Orangelandia was given an ultimatum by the U.N. Security Council* to stand down. With no sign of the occurring, the policy makers decide it’s time to act.
Darkness falls in Orangelandia. Satellites command the gliders forward. They drift further into the harbors, their targets are naval vessels they’ve monitored for days. The sailors on watch see and hear nothing more than what they attribute to the usual debris floating by on a moonless night. The gliders release their payloads – smaller drones that specialize in climbing the hulls of ships. After clamoring aboard the weatherdecks, the small machines avoid the sealed doors of the ships’ airlocks and feel out the superstructures, their goals the exhaust stacks for the ships’ engines and generators.
On a few ships at anchor the drones encounter humming engines and generators, beckoning the heat-seeking drones. Burrowing past the louvers the drones drop down through ducts and move towards the ships’ mechanical hearts. As the heat of the exhaust on the active vessels melts the drones’ exterior sheathing, thermal-triggered explosives carried in the drone cores detonate, delivering mission kills and rendering the ships immobile for weeks-to-months of critical repair. On the inactive ships it takes longer for the drones’ schematics-recognition features to determine the stacks’ location but the outcome is more devastating. The drones are able to move further into the exhaust system’s interior, detonating once progress is blocked, and increasing the likelihood of destroying the engines or generators themselves. Within the span of a night the majority of Orangelandia’s in-port fleet is crippled.
The above passage is of course a piece of fiction, and not very good fiction at that. But it doesn’t have to be. The technology to enable the scenario exists and will become more sophisticated and cheaper in the coming years. This is also far from the only way to imagine a “Drone Pearl Harbor,” as slightly different capabilities hold the potential to impact the way an attack could play out.
In developing a concept of operations for a stealth drone attack the ability to give the execute order is a sticking point. The technologically easiest course of action would be to simultaneously make both the decisions to set up for and to execute the strike at the beginning of the decision cycle, launching the drone operation as a “fire and forget” (or rather “fire and wait patiently”) strike. Yet few policy makers will want to make an irreversible decision far in advance of the impact of the effects. The decision to attack Orangelandia may be correct in the context of the 7th of the month, but not the 21st. One needs only remember the desperate attempts to recall the nuclear-armed bombers of Dr. Strangelove to grasp the concept.
However, any attempt to move the “execute” decision point later than the “set up” order, as I did in my example, faces technical hurdles. A direct transmission signal requirement would make the drones vulnerable to detection and possible hijacking or jamming. Using broadcast signals to transmit orders and obscure their location means leaving the drones even more susceptible to hijacking and jamming as Orangelandia could constantly emit signals to that end. Similar vulnerabilities exist when the drones are given reporting requirements, so an informed balancing of the need for one- or two-way communication and concerns over the exposures those needs create is necessary.
Variations on a Theme
The above scenario was played out against a generic surface ship. Other types of naval vessels have more accessible points of entry; and the job of penetration is made easier at less-stringent damage control settings that leave hatches and air locks open. Additionally the ways, means, and follow-on considerations of a drone sneak attack are also variable, but can be roughly broken down into fouling attacks, as in the scenario above; direct attacks; and cyber-attacks.
In a fouling attack, the drone payload would be used to achieve a mission kill against a critical piece of shipboard equipment. The drone would need the ability to locate that piece of equipment through some type of sensor – visual, thermal, chemical, etc. External targets, such as a ship’s propellers, would be the easiest to target. The benefit of a fouling attack is that the payload could be a small explosive, limiting drone’s size, likelihood of detection, and propulsion requirements for a trans-oceanic voyage. It could even be the drone itself, outfitted with special equipment or configuration options to inflict the maximum damage on the piece of critical gear. As an example imagine a piece of corrosive wire wrapping itself around the same hypothetical propeller. Again, the execute order in this type of attack could be withheld until very late in the decision-making process while the glider drones do “circles of death” in their lobos.
In a direct attack the glider drone would carry a weapon payload designed to inflict maximum kinetic damage. Such an attack would require less sophisticated targeting internal to the drone and could be used to attempt to disable a large portion of the ship’s crew and/or sink the ship. As with fouling attacks, direct attacks would be easier to conduct once the glider was on station and could incur the same delayed-decision benefits, the increased explosives requirement would increase the drone’s size and detectability.
In the last type of attack, a payload drone would find a way to penetrate the ship and access the ship’s industrial control systems (ICS), which operate things such as the ship’s main engines, to introduce a Stuxnet-like virus. Such drone would need to be small enough to fit through minuscule spaces or blend in during the process of crew traffic opening and shutting airlocks. The drone would also have to be the most advanced to successfully navigate around the ship unseen and interface with ICS through diagnostic, patching, or external monitoring ports. Such a drone could delay the policy-maker’s execute order until well after infection, potentially expanding the decision timeline until well after the drone has achieved its mission and the vessel has gotten underway. This delay would come at the cost of the very difficult task of being able to transmit the final execute order to the newly infected ICS, so the decision to infect the systems would more realistically have to be paired with the decision to execute virus’s programming. On the plus side, a cyber/drone sneak attack could potentially disguise the source of the attack, or even that an attack has occurred, unlike the other two types of attack, providing policy makers with further options than simply a kinetic attack.
That these courses of action are possible says nothing of whether executing any of them would be wise. The risk and potential repercussions of each course of action is as varied as the ways in which such an attack may occur. This is one reason I have attempted to draw out the effects different technologies have on moving the decision points. But possible they are, so it would be wise to both think of ways to take advantage of the options as new tools for policy makers, and think of ways to defend against them that don’t rely on weary roving deck watches. A few defensive options that come to mind include more stringent damage control settings in port, a thorough examination of the vulnerability of vessels and shipboard access points to drone penetrations, detection systems for drone penetrations, drone SIGINT detection and jamming, and possible external hardening of berths. But this is probably a good jumping off point for another post and your thoughts.
Scott Cheney-Peters is a surface warfare officer in the U.S. Navy Reserve and the former editor of Surface Warfare magazine. He is the founding director of the Center for International Maritime Security and holds a master’s degree in National Security and Strategic Studies from the U.S. Naval War College.
The opinions and views expressed in this post are his alone and are presented in his personal capacity. They do not necessarily represent the views of U.S. Department of Defense or the U.S. Navy.
*So no, Orangelandia is clearly not China, a veto-wielding member.
What do kids do when they get new set of Legos? Immediately start construction. Maybe in the beginning they will follow the assembly instructions, but soon discipline breaks and creativity wins. LCS, thanks its modularity, resembles a Lego set in some respects. AsChristopher Cavas noted on Information Dissemination:
Will some of the mission equipment not work well? Probably. Have something better? No problem. Change it. Bring stuff in and install it, ship stuff out, bring in different stuff.
While awaiting finalization of already defined mission modules, why not think about additional ones? For example, the SuW module has been designed to counter swarm attacks, based on experiences from Middle East operations. It would probably work well in Strait of Hormuz or even inFar Seas as defined by Dr. Andrew Erickson. But would it be as effective in China’s Near Seas? Later at Information Dissemination, Wayne P. Hughes summarizes his arguments in favor of distributed offensive power and risk. LCS is not conceptual like SeaLance, but installing Harpoons as a part of next SuW module could be a step in line with his reasoning.
ASW is another example. Although it stands for anti submarine warfare, is the conventional submarine the only underwater enemy of the future? If US Navy is pursuing autonomous robot projects, we should assume that our opponents are doing the same. The question arise what will be the best defense against future armed Bluefins or underwater gliders turned into intelligent mobile mines? Even if not armed, underwater robots are dangerous as scouts providing enemies with essential information. Will we need anti scouting module as well?
Recognizing all the challenges related to their development, inventing new modules seems to be unrealistic. Here our analogy could again be helpful. The inspiration for the whole concept of modularity came from Denmark, as did Legos. What Danes did with their StanFlex modules to minimize complexity and risk, was to take EXISTING systems and packed them into standardized container, a true Lego approach. So let us allow our creativity to wander, under subtle supervision of reason.