U.S. Navy Plans to Fly First Drone Swarm This Summer

The U.S. Navy's LOw-Cost Unmanned aerial vehicle Swarming Technology (LOCUST) is a prototype tube-launched UAV. The LOCUST program will make possible the launch of multiple swarming UAVs to autonomously overwhelm and adversary. (U.S. Navy photo via YouTube)The U.S. Navy's LOw-Cost Unmanned aerial vehicle Swarming Technology (LOCUST) is a prototype tube-launched UAV. The LOCUST program will make possible the launch of multiple swarming UAVs to autonomously overwhelm and adversary. (U.S. Navy photo via YouTube)

What happens when a swarm of slow, low-performance drones attacks a modern warship? With defense systems able to knock down supersonic cruise missiles and fast jets, small drones ought to be a turkey shoot. In fact, the situation plays out very differently.

The U.S. Navy is a leader in the area of swarm warfare, the threat has been analyzed in a number of papers from the Naval Postgraduate School analyze the threat. Some of these are classified, but a 2012 paper by Loc Pham, “UAV Swarm Attack”  is open and makes uncomfortable reading.

The paper posits a simple scenario: a Navy destroyer is attacked by five to ten drones simultaneously from all directions in conditions of good visibility. The drones are assumed to be made of off-the-shelf hobbyist components, controlled covertly from a nearby fishing vessel. Some of them are visually guided, others resemble the Israeli “Harpy” loitering drone which has radar guidance.

The defenders look well-prepared. The Aegis air defense system is one of the best in the world, with an integrated suite of sensors and weapons including jammers, decoys, Standard surface-to-air missiles, a five-inch gun and two Phalanx weapon systems, each with a multi-barreled 20mm canon spitting out seventy-five rounds a second. Aegis was assumed to be supplemented with six heavy machine guns on the deck.

The reason for the extra machine guns is that Aegis is not well suited to dealing with the threat. The small drones have a tiny radar signature, and by the time they are spotted they are too close to be engaged by missiles or the five-inch gun. The Aegis jammers are not designed to affect the drones’ control system and cannot affect them.  All the work has to be done by the Phalanx and the machine guns at close range. With the drones coming it at 155 mph, the defenders have just fifteen seconds between detection (at less than a mile) and impact.  It is vital that defenders pick a different target each, otherwise some drones take fire from several weapons while others slip through unscathed.

The team ran several hundred simulations, and found that on average 2.8 out of eight attackers got through. Even when the defenses were substantially upgraded — better sensors and more machine guns and Phalanx — at least one drone gets through every time. And that’s just with eight drones incoming. With a larger number — ten, twenty, fifty — the defenders would still only get the first seven or so.

This weakness means it makes sense to attack a ship with a large number of cheap drones than one missile costing the same, and that’s exactly what the Navy’s Low-Cost UAV Swarming Technology (LOCUST) program aims to do. The aim is to have thirty drones flying together without having to be individually controlled, maintaining separation safely like a flock of birds. They are different from any other drone in that the operator does not control an individual aircraft, but pilots the whole swarm as a single unit.

Dr. Lee Mastroianni, LOCUST’s project manager, believes the whole swarm can be made cheaper than a missile, and at $1.2 million for a Harpoon anti-ship missile he may be right. Locust is currently based on $15,000 Coyote drones. Of course these carry a much smaller warhead — but accurate targeting may be more important than the size of the warhead that hits. Knock out a ships’ radar, and it is a sitting duck for other weapons.

Mastroianni plans to have the his first swarm of 30 drones flying next summer.

The UAV Swarm Attack study highlighted the weakness of current defenses against swarms of drones. Timothy Chung, a scientist at the Naval Postgraduate School in Monterey, is looking at defensive swarms to take out the attackers. His project’s official name is “A System-of-systems Testbed for Unmanned Systems Swarm versus Swarm Development and Research,” but Chung calls it “Aerial Combat Swarms.”

Chung is staging a contest for swarms of small drones carry out simulated battles as a way of evaluating tactics and technology. His basic scenario is a 50-versus-50 encounter in which the Blue defenders attempt to stop Red attackers from getting through. Nobody knows much about drone-versus-drone combat yet, especially on this scale. How much autonomy do the drones need? How can the swarm commander stay in control in a fast-moving action?  How do quality and quantity balance out in battling swarms?

With manned aircraft, the pilot’s life counts for a lot; but swarming drones are expendable and high “casualties” do not matter. This is a very different world to the dogfights we have seen before.

The battles will be fought with small drones even cheaper than those used in LOCUST, but the tactics they discover may shape the future of warfare.

When a swarm of drones heads for an American carrier some time in the future, they might be intercepted by a defensive swarm. What happens next — whether the aircraft on the carrier’s deck are destroyed, or whether the attackers are beaten off — will depend on which side has the best grasp of an entirely new form of warfare.

About the Author

David Hambling
David Hambling is a freelance journalist, Military.com contributor and author based in South London who writes about science and technology. His most recent book is "Swarm Troopers: How Drones Will Conquer the World."
  • LouSassole

    Awesome, I was waiting for this to finally happen. It will work really well against the S-400

  • Bobby

    Having helped to develop and perfect Aegis and several weapons systems, need we mention my expertise both in Drone and UAV. They are right, the weakness in the system has always been there and we called it back in the 1980’s. My updated career from the old love boat AVN1 took me into UAV and drones and an a area I thrived in both in the USA, Iraq, Afghanistan and now for Saudi. There is only one true simple way to get a 100% every time and I am surprised by the 2.8 number or 28% failure and not 100% success. So I am shocked by their results. Former DCO Afghanistan, US Embassy

  • Tim

    To combat against this scenario is pretty easy. All you need is a missile and/or exploding projector near the center. With the massive explosion of warhead from a missile and/or projectile should get all of them. That or do severe damage so it knocks them out of the sky or path of direction.

  • Tim

    It will be easy to combat 30 mini drones. All you need is a missile and/or projectile with a exploding warhead near center of them all. With a massive explosion, it should kill them all and/or do enough damage to knock them down and/or off their direction.

    • TNT

      That certainly may be an effective way to eliminate some or even most of the drones but one can easily devise some strategies to avoid the missile/projectile explosion. For example, what if the drones followed a returning chopper or aircraft. Close proximity explosion my incur damage to friendlies. What if the drones were delivered via torpedo for most of the distance and pop up at the last instance to swarm. I think the scenario described creates a whole new dimension of surface ship warfare that will be an “arms race” of new tactics and countermeasures. Are we seeing the next evolution much like when surface ships went from big guns to missiles? My humble suggestion/idea would be to create a focused EMP weapon to disrupt electronics, a “ray gun” if you will.

    • TIm Marquart

      Sure but I think you are missing the point where they aren’t all just heading in as a group. Multiple high-number swarms from multiple directions. Its not so much that they are hard to kill, its that there are so many of them to kill. Reading this article made me think of a mosquito swarm. Your hand and OFF can get a lot of them, but you are going to end up itchy no matter what. Also, defending against those swarms distracts those same systems from defending against more coordinated attacks with traditional weaponry.

  • Brian

    Can’t wait until they perfect the laser system to quickly react and take out these type of swarms.

    • blight_

      It’s still a detection problem. Small footprint, long range. Unsure if EMP warheads would be useful, although the prospect of a EFP or a shaped charge is an interesting one. Sure, one drone/one EFP isn’t much, but a swarm of them might be interesting.

      Just as a flock of dive bombers could take out a battleship…

      • Carl

        But a laser only works well in clear weather, and it must focus on a single spot for a couple of seconds. A drone in flight is bouncing around due to turbulence and course corrections. It would be hard for a laser to shoot down a couple of them in that short engagement time, and they draw so much power a ship may have just two systems at best.

    • davidhambling

      The original analysis by Loc Pham looks at the laser option and concludes it does not make much difference. The drones are too close and take too long to kill for the laser to get many of them.

  • toadinhole

    This sounds like “Kill Decision” by Daniel Suarez. It is about swarming drones modeled after ant colony coordination. A scary book.

  • Jack Handy

    knew this was coming. guess u could use some type of directional spin up fragmentation bomb fired from launchers ringing the ship?

    or time for some kind of laser array

  • Jack Handy

    a phased laser array ringing the ship maybe

  • TNT

    just reviewed the Loc Pham paper referenced in the article.
    http://calhoun.nps.edu/bitstream/handle/10945/286

    A lot of interesting ideas discussed in the paper, including EMP as suggested by several readers here.

    • Carl

      But the EMP itself does not stop the missile. It will continue to fly forth and may still hit, especially at close range. Forget the heavy machine guns, I’d go with 7.62mm gatling guns. And get some canister rounds for the 5-inchers for eyeball directed aiming.

  • Racindavid

    Simple weapon needs simple defense; throw a net up in front of them. Rocket propelled or on blimps. You get the idea. A small drone will tangle up in them like a spider web….

    • kevthepope

      true, that seemed to bear out a lot in past wars, don’t overthink it, come to the level needed to combat it. even the equivalent of anti-personnel shot in the 5 inch guns to give a shotgun effect on small drones at a decent distance.

    • blight_

      Conversely, each high-value target will probably require a swarm of UAVs to form a perimeter..extend detection range and to ram incoming targets at high speed.

      Perhaps defensive swarm may be the way to go here, rather than offensive swarm.

  • Jack Handy

    or directed emp banks ringing the ship and also coverage above the ship

    for that matter why cant an EMP “bubble” of “shield” be created around the ship? hmmm…

    • TNT

      I think the limitation there is the amount of energy needed to create such a shield/bubble of that size. Now if we developed some DiLithium crystals into a warp core, then maybe we can start talking about a “shield”. That would be definitely prevent any small drones from getting through.

    • The problem is that it is much easier to shield small drones from EMP than ships. The defenders would suffer a lot more than the attackers if EMP were used.

    • Bill Beech

      directional EMP would have too many limitations, if you were in a fleet the pulse would disrupt your other ships or aircraft. Never is a battleship or carrier alone. Using the old basics, a chaff type blast from the ship is simple and could be in continuous blasts and a minimal expense.

  • TNT

    Was anyone else reminded of the final scene in Star Wars episode 4 when Darth Vader was informed the rebel ships are too small for the Death Stars canons? “We have to go after them ship by ship!”

    • blight_

      And that is why the Death Star needed CIWS

  • TNT

    Sorry, it was not my intent to trivialize the conversation. I do think that this is an incredibly fascinating topic that does require unconventional thinking. Sometimes, our current technology does catch up with what a few years ago was only considered science fiction.

    I do agree with your suggested idea of the bank of EMP emitters, as I suggested in my response to Tim’s comment. The paper also looked at that idea.

    Ideally, a shield would be the best so that it could protect against all size of drones and from all directions. I was just imagining how much energy that would require to generate an area that went out far enough in a hemispherical shape to prevent damage from detonation. In addition, how long could that energy source maintain the shields. These are all technical questions that are way beyond my knowledge base but I think those are the trade offs that the guys at DARPA are grappling with. The paper also included costs, feasibility of implementing, etc.

    Again, my apologies to you Jack. Sometimes the kid inside of my comes out. :)

  • JohnB

    Super easy solution to drone swarm, non-guided rocket propelled netting from the sides of the ship. The swarm UAVs have low thrust, lighter warheads meaning simple “webbing” shot in the air would disable the rotors. Look at old video how large lines are shot across gaps and you can get the concept. Even if the web is shot up at a 45 degree angle it would have “x” number of seconds of hang time allowing for a capture of the drones – all at once. You don’t need to send our own drone swarm to attack them. Fiber lines are so strong now those drones wouldn’t stand a chance. Plus the lighter war heads if detonated shouldn’t impact the ship even close in to the netting.

  • JohnB

    Following up on my own comment – think about the simple solution applied to the Bradley fighting vehicle in the face of old RPGs. Add a pre-detonation fence so the shape charge has the wrong focal point. Sometimes the simplest solution is the best. On Russian tanks they gave up on creating armor tough enough to stop an incoming round, instead they created reactive plate that deflect and destroy the incoming round. One system is airburst but the on that really works is within the plate and simple triggered by the velocity of the incoming round.

    • blight_

      Shaped charges are defeated by mesh cages, but EFP’s less so.

      • Carl

        I’ve thought of that too, but armored vehicles are armored, ships are not. They have skin not much thicker than a coffee can. If you try to fire reactive armor on the hull it would knock a hole back in the ship. And to cover the ship would add many thousands of pounds, making the ship slow and unstable.

        • runswithscissors

          I know this doesn’t affect your point but hull plate is typicality between 7/8″ on the bottom of the ship to 1/2″ on the sides…..much thicker than a coffee can.

    • BFVmikegolf

      The U.S. also has ERA (Explosive Reactive Armor) add on kits for the Abrams tank and Bradley Fighting Vehicle. The disadvantage of these are the additional weight and increased vehicle width which affect mobility. Another drawback with ERA is that it can only protect within a narrow angle of attack hit. In other words, if the incoming warhead is outside of the protection angle, the ERA is negated. The Stryker was originally planned to have add on armor to allow for RPG protection, but given the weight and the requirement for the vehicle crew, by themselves, to attach within a given time using only vehicle available tools (BII) the requirement could not be met. The original concept involved around 70 individual parts weighing just over 8,000 pounds with a four hour assembly time. This did not include the time involved to remove around two tons of hull attachments to mount the armor kit and then reinstall the removed hull parts. The “cage armor” was used as an alternative solution.

      • blight_

        If the enemy is forced to armor their ships, that’s weight carried that requires more structural reinforcement simply to carry around. And you can’t slap armor onto a destroyer, you’d have to re-engineer your next generation of ships to carry the stuff.

        If it’s cheaper for us to build our drone swarm than it is for adversaries to counter it…and cheaper for us to stay ahead while they simply react to our technological developments, we win.

  • BoutteBob

    What are the ranges of the drones, can’t be that far, they are small carrying a warhead, this all limits the range.. The mother ship, or whatever, can’t be far away, just SINK IT…LOL..LOL.. End of problem..

    • Even small drones can have a range of thousands of miles – check out Swarm-Troopers.com

  • JohnB

    Drones should not require a “mother ship”. Once pattern recognition is done of the ship it just follows it in using a simple vision system. Hell, you could use a raspberry pi to create one. Ships travel slow – easy targets to acquire using vision versus radar (eliminating the false radar signatures are current ships can create) Can also combine a simple flair system as backup but these things should be autonomous in nature. Still doesn’t defeat the polymer netting system I mentioned earlier. That’s a foul proof way to stop everything flying near your ship the instant you need it to.

  • steve

    A few men on deck armed with shot guns

  • freedom

    Its a bird. Its a plane. No! Its a drone and it will give you freedom!

  • Joe

    This won’t be a problem. We will use “sharks with freakin lazers on their heads”.

  • jdev17427

    “controlled covertly from a nearby fishing vessel” and so how does that vessel and the drones defend against electronic jamming? Now if those drones are autonomous one day….carrying explosives, electronic jammer weapons themselves or other weapons (like biological / chemical /micro-nuclear weapons)…. now then you have something.

  • stupid

    Give marines a baseball bat and a jet pack.

  • pyrios

    Why couldn’t you use a small missile loaded with a type of silly foam, like the kids get in a small can. And detonate a few of them, from the center of the swarm covering the drones in the foam and watch them fall out of the sky.

  • alia

    i’m alia conte conakry guinea i like usa of america navy game very great navy round the world very good and very style navy so good and very power.(i’m alia conte)

  • oakitoki

    Just need a big fan and a big fly swatter. kekeke.

  • casra4@yahoo.com

    Our military has become to dependent on technology. These drones are nothing more than a waste of taxpayer money. Why does everyone involved in the drone program in this country not see the millions or billions being wasted on a technology that might have worked in the second world war but is totally useless on the modern battlefield. They’re slow and easily shot down so why waste the money on the idea of swarm attacks?

  • Chris

    Everyone needs to read the news. Shot guns work very well against drones and cost very little. It would be very easy to place a watch to guard venerable systems to small drone attacks. could even place mounted automatic shotguns in the same areas that simply send a constant volley protected the area during the small attack window while watch standers take out the threat or the phalanx gains time to take out all threats either way low tech will prevent this attack which can only hit low armored areas.

    • blight_

      Indeed. If the drones are too slow they’ll be amenable to being picked off with small arms, a fifty-cal or a 20mm or other weapon of choice. If they are evasive sea-skimmers with low radar cross section, modest/non-existent IR and are launched at night they will be interesting. If they are low speed, have the radar cross section to be picked up by CIWS they are toast.

      Since you and steve seem to think shotguns will work, the possibility of a mixed force of drones is a legitimate one. Have some drones with 20mm cannon (or a .50) hose down the deck, targeting unarmored deck guns, CIWS, VLS, the bridge, radar systems, with other drones carrying suicide payloads either targeting the above the waterline goodies or going at the waterline to cause flooding.

  • Woody

    Seems a directional EMP emitter would fry the drone circuits and render them useless and would drop like flies…

  • jorex

    Intercept them with high speed helicopters with a big net hanging out from its belly just like a fishing boat would do.

    • blight_

      If you can detect them already you just wait for CIWS to kill them.

      Although CIWS ammunition supplies are not inexhaustible…using drones to exhaust anti-missile guns and missiles is a use we have not discussed yet.

  • JCR

    The Israelis have the Trophy for protection system for their tanks. Use the same or modified defense system for tanks against RPG’s and missiles.

  • JCR

    That is, the Trophy protection system for tanks could be modified for protection against drones.

  • thexfile

    Hack the GPS system.

  • blight_
  • Fred

    I disagree that our systems are EMP protected. However, what about other frequency jamming techniques to disable control in an effected area. I am also surprised that this is published and not at least confidential limited distribution.

  • Fred

    Oh, and one from old gaming techniques against invisible opponents, a paint bomb, big explosion of opaque liquid that sticks to the drones, to mask the camera controls. Variations to increase detect-ability of first defense survivors, radioactive paint, corrosive or glue bombs.

  • Carl

    And remember the torpedo bombers of WW II? Some drones will drop a small torpedo into the water once they’ve locked on the ship from the air. Good luck with that. Or just launch an attack during a rainstorm and the ship will not see anything that small incoming. Some will argue that ships will be safe if they stay 1000 miles offshore, avoiding offshore islands, shore fire, and small local boats and aircraft. Fine, but then a Navy can do little hiding at sea.

    • TonyS

      This discussion needs intelligent input regarding the anticipated size of the drones by people in the know – where are they? What is the lift capability and range of various types of drones?
      If the drone has got a 1lb warhead it’s relatively small and could be taken out by heavy automatic shotguns.
      The WWII torpedo bombers were BIG aircraft – if the drone was big enough to drop a torp – even a small one – it would be extremely large and therefore cannon fodder for the Phalanx.
      Perhaps we should be talking about rapid-fire lasers?

      • davidhambling

        The Harpy (aka Harop) drone in Loc Pham’s orginal study has a range of 300 miles and carries a 70 lb warhead. It would not need to be much bigger to carry a modern lightweight torpedo like the Compact Rapid Attack Weapon.
        In practice, attack drones in a swarm could be all shapes and sizes from Coyote-size to huge, with plenty of decoys in the mix.

  • Just Me

    I can see where drones and drone swarms are the new tool / countermeasure to ratchet up spending among all the capable adversaries, including China, Russia, Israel, Iran, India and more. Especially after reading about some of the other’s drone developments.

  • Erik

    big fan or drop a big net over them? blast them with water cannons?

  • Alex

    I think the key to a decent laser-based (or microwave) defense is agile non-mechanical beam steering. Laser AA good if can resolve and track, microwave good for frying clusters of objects & comm.

    Ref. comment above about rain/weather obscuring the drones: a real issue … but it would seem to work both ways – though a ship
    is a lot fatter target up close.

  • Kevin

    A drone of that size would have a very limited range. Payload or propulsion , pick one, you can’t have both. So your starting point is already within range of the enemy ship.

  • Nick

    People are dreaming if they think that “swarm” will be a tightly-grouped pod that can be taken out with one well-placed shot. The swarm will intelligently analyze the target, classify it, determine it’s likely weapons capabilities, and then execute an attack plan that is optimized for that target. The Chinese are already on this. The swarm will also expand/contract dynamically and alter their attack vectors as units within the swarm stop communicating with the other swarm units (e.g. they get destroyed). The swarm will also intelligently attack the highest-value hardware first and then work it’s way down. There is NO PRACTICAL WAY to stop an intelligent, dynamic swarm using conventional weapons. Until lasers progress substantially in tracking speed and time-to-kill, your only practical option is to launch a counter-swarm (e.g. a swarm-killing-swarm).

  • aegisk

    social swarming patterns and whole colony insect , social flora fauna etc. fractal pattern association of eco, set into hæl for company, relationships and associations patterns. defense is a natural cog of god and man, ver man.
    ay’ya
    shrink the navy !!!

  • chuckiechan

    I can just see little missiles about the size of a cigarette mounted on their little wings, ready to take the fight to the rebel forces!

    I wonder what kind of “payload” and enemy drone will be carrying? 25 lbs just “splat” on the side of an aircraft carrier?

  • davidhambling

    25 pounds is more than enough to take out a plane on the deck – a pretty good exchange.

  • Eric austin

    What about a swarm of underwater drones?? How does a ship protect itself from that???