Military Drone Swarms and the Options to Combat Them
By Ryan Bridley and Scott Pastor
The tactical use of drones is expanding as demonstrated from the past 100 years. Drones were first created in the U.S. and United Kingdom during World War I, though neither country employed them during the war.1 In World War II, the Nazis created the V-1 to serve as a missile.2 The U.S. employed drones for surveillance missions during the Vietnam War and utilized them frequently for counter-insurgency surveillance and strikes in Iraq and Afghanistan. Drones are now developed in and utilized by over 100 countries and non-state actors.3 Drone capabilities, manufacturers, and customers will likely continue increasing and a tactical shift in utilizing drone swarms is emerging. This article provides a broad overview on the current state of drones for commercial and military use, the impact drone swarms can play in the military environment, and the options available to combat swarms.
The Current State
DJI is a privately-owned Chinese company that manufactures more drones than any other company. In 2021, DJI produced 54% of all commercial drones worldwide and accounted for nearly 80% of commercial drones ordered by the U.S.4 Many American DJI customers are safety-based organizations like police departments and the National Park Service.5 Regardless of whether these organizations understand that China is a global competitor of the U.S., they purchased DJI’s drones due to their affordability and suitability for mission needs.6
If DJI or one of its competitors starts selling inexpensive military drones or commercial drones that can be weaponized by a third party, the global impact could be significant. For example, the Turkish Bayraktar TB2 drone, capable of carrying four MAM missiles, was used for engagements in Libya, Syria, and Azerbaijan, and then sold to Ukraine at $5 million per unit for its conflict with Russia. As of May 2022, the TB2 is responsible for the destruction of 750 land vehicles (including tanks), aerial vehicles, and artillery pieces.7 The TB2 demonstrates there are drones made by companies outside of the U.S., which are fully capable of meeting foreign military demands. In turn there may be a growing global demand for suicide drones.
Suicide drones are unmanned aerial vehicles (UAVs) furnished with explosives, which cause the drone to detonate upon impact with another object. The current Ukraine-Russia conflict is seeing both sides use suicide drones. Russia is employing the ZALA KYB, which can remain in the air for 30 minutes and carries six pounds of explosives, making them dangerous against soft targets.8 Ukraine is utilizing or is in the process of receiving over 500 American Switchblade suicide drones in two variants. The Switchblade 300 can be controlled by an operator six miles away, weighs six pounds (making them easy to transport by ground troops), can stay airborne for 15 minutes, and is effective against dismounted troops and light military vehicles.9 The Switchblade 600 possesses a range of 24 miles, weighs 50 pounds, is able to remain airborne for 40 minutes, and can destroy heavily armored vehicles. Both Switchblade variants can be constructed in minutes and launched like a mortar.10 From this conflict, both sides are demonstrating a strong willingness to employ a high number of drones for tactical advancements.
Impact of Drone Swarms
As developments unfold on the effectiveness of drones in Ukraine, there will likely be a growing interest from countries and militant organizations to adopt drone swarms. A swarm is the utilization of numerous drones at one time, which communicate with each other and inform their operator of battlefield developments. Swarms can employ single or multiple drone types and countries such as South Korea and South Africa are assimilating their own swarms for military use.11 Businesses are also recognizing the commercial value of creating drones which can operate as a swarm. For example, Puerto Rican company, Red Cat Holdings, possesses a drone that can be controlled in conjunction with five other drones by one operator. Of the six drones, up to four can be flown while the other two remain on backup status, ready to replace a mobile drone should it be unable to fly or low on energy. Further, a Red Cat swarm can surround a target while providing video feed from multiple perspectives and they can capture imagery of an area by taking separate photos and piecing them together to create a comprehensive graphic.12
The capabilities of swarm systems directly apply to military reconnaissance and surveillance missions. For surveillance of stationary and moving targets, swarms can be positioned to observe both a target and a target’s periphery for external activity. This includes a simple operation such as watching a suspected enemy compound while looking for vehicular traffic moving to or from the location. For viewing a widespread location, the swarm drones can simultaneously capture photos of various points, thereby reducing the mission time expected of a single drone. This capability lends itself to monitoring a location for activity changes in which the swarm can quickly capture a widespread area image on a periodic basis. This was demonstrated by the Israel Defense Forces’ (IDF) conflict against Hamas in May 2021. During the conflict, Hamas shot thousands of mortars and rockets from the Gaza Strip, while ensuring their launch locations remained largely hidden underground or in civilian establishments. IDF responded by deploying drone swarms to observe suspected launch sites. Through their observation, the drones detected from where and when Hamas was firing, enabling IDF to conduct strikes against those positions.13 Swarms have proven to be useful for reconnaissance and surveillance, and they can also be effective if weaponized.
For domestic security operations, swarms can be used by national defense forces to counter threats against extremist organizations. In 2016, the Iraqi Army launched four strikes with Chinese CH-4 drones that killed 10 ISIS combatants. In the same year, the Nigerian military launched its first armed drone attack with Chinese CH-3s against the Boko Haram terrorist group.14 Both attacks were launched within each country’s respective borders. From incidents such as these, foreign governments are showing a willingness to acquire and employ swarms against domestic insurgents.
Drone swarms also have value in supporting security and defense missions. The U.S. Air Force conducted simulations in 2020 to study how inexpensive military swarms can defend Taiwan and U.S. bases in Japan from attacks by China’s People’s Liberation Army. Former Deputy Assistant Secretary of Defense for Force Development, David Ochmanek, offered the following findings from these simulations.
- The U.S. will be challenged not just with gaining air superiority, but even entering an airspace where China is pre-emptively directing missiles and warplanes.
- Swarms with a radar signature like the F-35 can fly ahead of American or allied aerial vehicles. In this capacity, drones can serve as decoys and influence adversaries to expend some of their missiles.
- Swarms flying lead can detect adversarial electronic signatures and thereby air defense locations. This enables the aerial vehicles flying behind the swarms to know where not to fly and where and when to turn off their radar.
- Swarms can theoretically be controlled by artificial intelligence so commanders can focus on other mission developments.
This scenario along with other studies are influencing the U.S. to encourage Taiwan to incorporate more drones into its fleet.15 These findings offer how drones can partially neutralize enemy air superiority, confuse radar detection, and be of interest to a country that wants to protect its security from a global power.
Swarms are also proven to be highly effective in a purely offensive capacity. In the 2020 Nagorno-Karabakh War, Armenian forces were stopped by Azerbaijan despite Armenia possessing more modern equipment and more troops. A major reason for this is that Azeri forces utilized numerous types of weaponized drones including the Turkish Bayraktar TB-2, which terminated nearly 250 armored vehicles and 40 air-defense systems. After the swarms severely damaged Armenia’s land and air defense capabilities, Azeri forces enacted mechanized infantry operations to seize contested territory.16 A military initially thought to be disadvantaged utilized swarms to enable its offensive capabilities. These swarms destroyed hundreds of assets, weakened Armenia’s ability to wage war on the ground and in the air, and provided the Azeris an opportunity to conduct a decisive strike.
Options to Counter Swarms
As more countries and organizations understand how swarms can be employed, there is a need to understand how to defend against them. There are several options that can be partially successful to include the use of microwaves, lasers, jamming systems, building underground, and fighting swarms with other drones.
Two options deemed to be unsuccessful, whether employed individually or together, are the use of machine guns air defense systems. While both provide the firepower needed to destroy drones, machine guns are restricted in the angles from which they can fire and lose accuracy with increased distance and periods of limited visibility such as nighttime and inclement weather.17 Meanwhile, air defense systems suffer in their ability to locate targets at low altitude as they are positioned to stop enemy missiles traveling at high elevations. An adept operator can navigate a swarm to fly close to the ground and under an air defense system’s monitored airspace.18
Unlike machine guns and air defense systems, the transmission of radio frequency (RF) energy in the microwave spectrum offers more promising results for swarm defense. The U.S. Air Force Research Laboratory developed the Tactical High Power Operational Responder (THOR), an electromagnetic weapon that can be moved by a C-130 and assembled by two people within hours. THOR emits widespread RF energy, capable of reaching numerous drones in an instant. When this energy reaches a swarm, it overwhelms the circuitry in the drones, causing them to crash. This concept is proven effective in studies with hundreds of drones.19 Encouraged by THOR’s initial results, the U.S. Air Force is looking to expand the technology with a system called Mjolnir, which employs RF saturation over a longer range and with drone detection capabilities.20 While THOR and Mjolnir efforts are hopeful, they are in their nascent stages of development and may prove cost-prohibitive to poorer countries.
A different option being studied by several countries to combat swarms is the use of laser technology. High-powered lasers can heat their targets to the point of component and circuitry failure. When paired with tracking radar, lasing systems can strike targets with great accuracy and severe impact. However, fog, clouds, or smoke can diffuse laser energy in same way they can with light and reflective surfaces can weaken and redirect laser energy away from a target. The use of lasers will likely be unreliable for militaries in dense weather conditions or low-visibility areas. Further, covering drones in a reflective coating may be effective in protecting them from lasers. If such a coating can be applied, it would provide those with offensive swarm capabilities a straightforward way to shield their fleet.21
A more traditional approach to fight swarms is to use jamming systems to obstruct the radio frequencies that operators use to control drones. This can be especially effective against low-quality drones. When executed correctly, jamming disrupts flight paths, causing drones to stray or crash. Yet, drones can be programmed with inertial navigation to enable them to land or return to their operator if a jamming attempt is identified. Drones with jam-resistant forms of communication are also being manufactured by high-level vendors.22 Jamming is an affordable countermeasure against basic drones, but that effectiveness will decline against drones with sophisticated resistance capabilities.
A passive way to withstand a swarm is to build potentially targeted facilities and weapon systems underground. Traditionally, key facilities and weapons have been placed in secluded areas where they cannot be observed or accessed. With more organizations gaining aerial viewing and imagery capabilities, it is less likely for a site to be identified if it is below ground than remote and above ground.23 However, building underground requires considerable time and financing, which may be undesirable for an organization that is under a present drone or surveillance threat or lacks funding.
An additional method to fight invading swarms is to employ defending drones. Using defending drones can be helpful as they do not have to be synchronized to still be somewhat effective. Defending drones can destroy some of the invading swarm and they offer the invading swarm more targets which can disrupt the swarm’s mission and blunt its attack. Defending drones can be at risk of receiving friendly fire from other defending drones, but if they are inexpensive, the risk is not as impactful. Still, while potentially effective, using defending drones requires operators to be on standby and is unlikely to defeat an entire swarm without the support of other swarm defense systems.24
There are numerous options to combat drone swarms, but all of them possess notable shortcomings. Countries and organizations under a swarm threat will need to decide which option or combination of options they are willing to accept. In turn, there will be a growing demand for a more decisive and reliable system to defeat offensive swarms.
As drone capabilities continue evolving so too will drone swarms. More foreign governments and non-state actors will likely consider adding swarms to their military arsenal, which will prompt a response of understanding of how to enact swarm defenses. It is in the U.S.’ interest to continue monitoring and studying swarms so we understand the changing role they play in the tactical setting and how they can affect our security concerns.
1 “A Brief History of Drones.” Imperial War Museum, accessed June 11, 2022. https://www.iwm.org.uk/history/a-brief-history-of-drones
2 “V-1 Cruise Missile.” National Air and Space Museum, accessed June 11, 2022. https://airandspace.si.edu/collection-objects/v-1-cruise-missile/nasm_A19600341000
3 “Timeline of UAVs.” Public Broadcasting Station NOVA Science Programming on Air and Online, November, 2002. https://www.pbs.org/wgbh/nova/spiesfly/uavs.html“Combat Drones: We Are in a New Era of Warfare – Here’s Why.” British Broadcasting Company, February 4, 2022. https://www.bbc.com/news/world-60047328
4 Gina Chon. “DJI Is a More Elusive U.S. Target Than Huawei.” Reuters. December 16, 2021. https://www.reuters.com/market/asia/dji-is-more-elusive-us-target-than-huawei-2021-12-17/
5 Gina Chon. “DJI Is a More Elusive U.S. Target Than Huawei.” Reuters. December 16, 2021. https://www.reuters.com/markets/asia/dji-is-more-elusive-us-target-than-huawei-2021-12-17/
6 “DJI Statement on Military Use of Drones.” DJI. April 21, 2022. https://www.dji.com/mobile/newsroom/news/dji-statement-on-military-use-of-drones/
7 “Bayraktar TB2.” Military-Today. 2022. http://www.military-today.com/aircraft/bayraktar_tb2.htm; Paul Iddon. “Iranian, Turkish, and Israeli Drones Will Be Built in Other Countries.” Forbes, May 24, 2022. https://www.forbes.com/sites/pauliddon/2022/05/24/iranian-turkish-and-israeli-drones-will-be-built-in-other-countries/?sh=4e4bd8dc1e5c
8 Ameya Paleja. “Russia and Ukraine to Use Suicide Drones in Armed Conflict.” Interesting Engineering, March 29, 2022. https://amp.interestingengineering.com/drones-russia-ukraine-conflict/“Russian ‘Suicide Drones’ Blasting Ukrainian Positions Appear Online; Experts Say Moscow Could Use Them As ‘Aerial Minefield.’” Eurasian Times, March 13, 2022. https://eurasiantimes.com/russian-suicide-drones-blasting-ukrainian-positions-appear-online/
9 “Watch the Switchblade Suicide Drone in Action Against a Russian Tank.” Special Operations Forces Report, June 4, 2022. https://sofrep.com/amp/news/watch-the-switchblade-suicide-drone-in-action-against-a-russian-tank/; Jennifer Hassan, Dan Lamothe, and Annabelle Timsit. “What Are Switchblade Drones, the Kamikaze ‘Killer’ Drones Biden is Sending to Ukraine?” The Washington Post, March 17, 2022. https://www.washingtonpost.com/world/2022/03/17/switchblade-drones-ukraine-russia-biden-war/; David Hambling. “Failure or Savior? Busting Myths About Switchblade Loitering Munitions in Ukraine.” Forbes. June 8, 2022. https://www.forbes.com/sites/davidhambling/2022/06/08/failure-or-savior-busting-myths-about-switchblade-loitering-munitions-in-ukraine/amp/
10 Jen Judson. “AeroVironment Debuts Bigger, Anti-Armor Loitering Missile.” Defense News, October 1, 2020. https://www.defensenews.com/land/2020/10/01/aerovironment-debuts-bigger-anti-armor-loitering-missile/Jennifer Hassan, Dan Lamothe, and Annabelle Timsit. “What Are Switchblade Drones, the Kamikaze ‘Killer’ Drones Biden is Sending to Ukraine?” The Washington Post, March 17, 2022. https://www.washingtonpost.com/world/2022/03/17/switchblade-drones-ukraine-russia-biden-war/
11 Zachary Kallenborn. “Swarm Talk: Understanding Drone Typology.” Modern War Institute at West Point, December 10, 2021. https://mwi.usma.edu/swarm-talk-understanding-drone-typology
12 Loz Blain. “You Can Now Buy a Coordinated Multi-Drone Swarm in a Box.” New Atlas, June 2, 2022. https://newatlas.com/drones/red-cat-drone-swarm-product/
13 Judah Ari Gross. “In Apparent World First, IDF Deployed Drone Swarms in Gaza Fighting.” The Times of Israel, July 10, 2021. https://www.timesofisrael.com/in-apparent-world-first-idf-deployed-drone-swarms-in-gaza-fighting/
14 Peter Bergen, Melissa Salyk-Virk, and David Sterman. “World of Drones.” New America, July 30, 2020. https://www.newamerica.org/international-security/reports/world-drones/
15 Joseph Trevithick. “Massive Drone Swarm Over Strait Decisive in Taiwan Conflict Wargames.” The War Zone, May 19, 2022. https://www.thedrive.com/the-war-zone/massive-drone-swarm-over-strait-decisive-in-taiwan-conflict-wargames
16 David Hambling. “The ‘Magic Bullet’ Drones Behind Azerbaijan’s Victory Over Armenia.” Forbes, November 10, 2020. https://www.forbes.com/sites/davidhambling/2020/11/10/the-magic-bullet-drones-behind--azerbaijans-victory-over-armenia/?sh=37cd9cf35e57Steve Balestrieri. “Countering Small Drone Swarms Has Pentagon Worried.” Special Operations Forces Report, April 22, 2021. https://sofrep.com/news/countering-small-drone-swarms-has-pentagon-worried/
17 Matthieu J. Guitton. “Fighting the Locusts: Implementing Military Countermeasures Against Drones and Drone Swarms.” Scandinavian Journal of Military Studies, January 13, 2021. https://sjms.nu/articles/10.31374/sjms.53/
18 Seth J. Frantzman. “Are Air Defense Systems Ready to Confront Drone Swarms?” Defense News, September 26, 2019. https://www.defensenews.com/global/mideast-africa/2019/09/26/are-air-defense-systems-ready-to-confront-drone-swarms/
19 David Roza. “A New Air Force Weapon Will Wipe Out Drone Swarms with the Push of a Button.” Task & Purpose. August 5, 2021. https://taskandpurpose.com/military-tech/air-force-drone-swarm-defense-mjolnir/
20 Stephen Losey. “Killing Drones with Thor’s Hammer: Air Force Eyes Counter-UAS ‘Mjolnir’ Weapon.” Defense News, February 28, 2022. https://www.defensenews.com/air/2022/02/28/killing-drones-with-thors-hammer-air-force-eyes-counter-uas-mjolnir-weapon/
21 Matthieu J. Guitton. “Fighting the Locusts: Implementing Military Countermeasures Against Drones and Drone Swarms.” Scandinavian Journal of Military Studies, January 13, 2021. https://sjms.nu/articles/10.31374/sjms.53/
22 Martti Lehto and Bill Hutchinson. “Small Drones’ Swarms and Military Paradigm Change.” Proceedings of the 16th International Conference on Cyber Warfare and Security (163), February 25-26, 2021. https://books.google.com/books?hl=en&lr=&id=BpgjEAAAQBAJ&oi=fnd&pg=PA159&dq=jamming+drone+swarms&ots=tI920hFGlG&sig=xHMqqp5-afHcOvV8tHYmxjP3pRQ#v=onepage&q=jamming%20drone%20swarms&f=false
23 Matthieu J. Guitton. “Fighting the Locusts: Implementing Military Countermeasures Against Drones and Drone Swarms.” Scandinavian Journal of Military Studies, January 13, 2021. https://sjms.nu/articles/10.31374/sjms.53/