What Are Drones?

Introduction

We are living, increasingly, in a drone-saturated world. In recent years, drones, or unmanned aerial vehicles (UAVs), have proliferated rapidly around the globe in both military and civilian spheres.¹ Today, at least 90 nations and non-state groups are known to operate drones, including over 10 countries with armed drones.² An additional 20 countries have armed drone programs in development.³ As this technology continues to proliferate, simple weaponized drones will be increasingly within the reach of virtually any state and many non-state actors. Already, non-state actors such as Hamas, Hezbollah, the Islamic State of Iraq and Syria (ISIS), and Libyan rebel groups have used drones to conduct tactical surveillance.⁴ Individuals also have access to increasingly sophisticated commercial off-the-shelf drones and components that can either be used for surveillance or weaponized. Indeed, even without missiles or releasable bombs, drones can be used as cheap precision-guided weapons to disperse chemical or biological payloads or simply to strike targets with explosives. If used in large numbers, these systems could potentially enable states, non-state groups, and individuals to achieve overmatch against a significantly more capable adversary.

As drones continue to proliferate, it will be vital for policymakers to understand the underlying technologies and the capabilities these technologies will provide to various actors. Current drones vary widely in affordability, accessibility, and capability – from inexpensive, commercially available systems flown by short-range joystick controls to multimillion-dollar, high-end military-grade systems that require substantial training and infrastructure to operate. This paper will therefore examine and categorize UAVs based on two characteristics: (1) the degree to which they are accessible to any given actor; and (2) the technology base and infrastructure required to produce and/or operate them. Using this taxonomy, the paper identifies four categories of systems.⁵

Nor are these systems confined to nation-states alone. Both Hamas and Hezbollah are known to operate midsize military-grade systems, believed to be variants of the Iranian-supplied Ababil-1 and Mohajer 4, respectively. They have repeatedly flown these systems into Israeli airspace, penetrating as far as 225 kilometers into Israel.³² Indeed, Hezbollah’s Mohajer 4, which it calls the Mirsar, was able to elude Israeli radar on several occasions due to its small size.

Similarly, Libyan rebels employed a tactical, night vision-equipped commercial surveillance drone – the Aeryon Scout Micro UAV – in their fight against Moammar Gadhafi’s forces. Weighing in at just over a kilogram and capable of being transported in a backpack, the Scout Micro provided the rebels with a portable ISR option that enabled them to identify and collect information on government artillery positions. Additionally contributing to the Scout’s utility to the rebels, the drone was controlled via a map-based touchscreen console and required less than a day of training to operate.

While these midsize commercial and military systems were originally intended as reconnaissance platforms, like hobbyist systems, they can be – and have been – weaponized. Though these systems may not be large or sophisticated enough to carry a releasable bomb or missile at present, they can carry explosives or other hazardous materials and can thus function as precision-guided kamikaze weapons, blurring the line between UAVs and small missiles.³³

For example, in 2013, Palestinian security forces detected a Hamas plot to launch armed UAVs into Israel.³⁴ Hezbollah met with greater success during the 2006 Lebanon War, when it managed to fly drones laden with a total of 27 kilograms of explosives and projectiles near major cities in Israel and Lebanon.³⁵ Though the drones were ultimately shot down, they held the potential to inflict significant damage on civilian populations. While both Hamas and Hezbollah have large quantities of unguided rockets that they have launched into Israel on numerous occasions, UAVs could increase the precision of an attack, resulting in a greater ability to inflict casualties or strike specific high-profile targets. In addition, drones can be more challenging to shoot down than rockets since they do not follow a high, ballistic trajectory – a factor that complicates detection and interception. This threat will only increase as such organizations gain access to systems that are capable of launching missiles, or as miniaturized missiles such as Raytheon’s Pyros (small tactical monition) or Textron’s Fury become more accessible.³⁶

These capabilities hold substantial destructive potential that terrorist organizations and other disruptive actors are likely to exploit. Indeed, as Yochi Dreazen has written the world is fast approaching “the next evolution of warfare-by-remote-control, when weaponized robotic planes give terrorist groups de facto air forces.”³⁷

Summary

Midsize commercial and military drones, ranging in cost from tens of thousands of dollars to no more than a couple million dollars, are widely available for purchase by states and industry. They may also be procured and operated by more established or well-organized non-state actors with limited supporting infrastructure.

Additionally, many military-specific systems have the capacity for a weapons payload. Indeed, over 10 countries currently possess armed drones, with around 20 more openly reported to have active developmental programs.⁴⁶ It should be noted, however, that there is a range in the sophistication of armed drones – from Israel’s and the United States’ highly advanced systems to Nigeria’s less-sophisticated Chinese-origin models. For example, General Atomics’ MQ-9 Reaper carries “up to 14 [AGM-114] Hellfire missiles … or various combinations of the GBU-12 Paveway II laser-guided bomb, the AIM-9 Sidewinder, or the GBU-38 JDAM.”⁴⁷ Systems such as the armed Reapers, currently operated by only the United States and the United Kingdom, thus provide a flexible menu of options for precision-guided air-to-air, anti-personnel, and armor-piercing capabilities that can be delivered at a range of approximately 9 kilometers, from altitudes of up to 50,000 feet.⁴⁸ This range, in turn, increases the difficulty of detection and neutralization from a counter-air perspective, falling outside the range of, for example, many widely operated MANPADS. This stands in contrast to Nigeria’s CH-3, which reportedly carries only two air-to-ground missiles and can reach altitudes of no more than 20,000 feet.⁴⁹ In addition, while large military-specific drones offer a relatively high level of sophistication, without stealth or electronic attack capabilities they will remain vulnerable to advanced air defenses as well as to enemy fighter aircraft.

Furthermore, the proliferation of armed systems – either through indigenous production or transfer – shows no signs of slowing. Pakistan recently announced that it successfully fired a laser-guided missile from its Burraq UAV.⁵⁰ And with the State Department’s recent amendment of U.S. export control policy, long-standing requests for armed Reapers by Italy and Turkey will now be reviewed.⁵¹ There are additional reports that Australia, already training with armed Reapers, is interested in purchasing the system as well.⁵² While armed drones accounted for just 2.6 percent of all global UAV transfers from 2010 to 2014 (or 11 of 428), the number is steadily increasing – up from 1.5 percent from 2005 to 2009 (5 of 317 systems transferred) and 0 percent from 1985 to 2004 (of 813 systems transferred).⁵³ In the years to come, the number of countries with armed drones can be expected to increase further.

Summary

Highly sophisticated military-specific drones, costing in the millions of dollars, currently require substantial training and infrastructure to operate. Because of that, they are neither accessible to nor affordable for non-state actors and many state militaries. Nonetheless, the increasing number of indigenous producers and growing international market suggest that an increasing number of countries will possess armed drones in the next 5 to 10 years.

Stealth Combat Drones

Stealth combat systems, including ISR and armed UAVs, represent the highest levels of technological sophistication – akin to the most advanced, fifth-generation fighter aircraft. While a number of countries have developmental programs for such systems, only the United States is known to operate them. Furthermore, due to the sensitivity of stealth combat drones, the United States does not export them and rarely discusses their existence or capabilities in public.

Capability Overview

Although many stealth combat systems are classified, defense officials have confirmed the existence of two: Lockheed Martin’s RQ-170 Sentinel and Northrop Grumman’s RQ-180 – short- and medium-range stealthy ISR UAVs, respectively.⁵⁵ Both systems are reportedly designed to minimize their radar cross-section via low-observable features such as stealth coatings that absorb the radio waves of adversary radar and shaping measures that minimize radar reflection. Indeed, neither system has the radar-reflective vertical stabilizers found on most manned aircraft; the systems are instead shaped like tailless flying wings with, according to open-source reporting, specially designed inlets and exhaust – features that improve broadband, all-aspect stealth.⁵⁶

Like fifth-generation aircraft, these and other stealth combat drones are also likely to feature low-probability-of-intercept/low-probability-of-detection communications that can transmit data while in stealth mode, as well as an array of passive sensors. This suite of technologies, in turn, enables stealth combat systems to operate in contested and denied environments that contain advanced, integrated air defense systems – a capability not resident in less sophisticated UAVs.

Although no other currently operating, publicly acknowledged drones feature such technologies, reports indicate that BAE Systems’ Taranis and Dassault Aviation’s nEUROn – jointly developed by France, Italy, Sweden, Spain, Greece, and Switzerland – will have similar stealth features when they eventually become operational, as will systems being developed by Russia, Israel, China, India, and South Korea.⁵⁷ Furthermore, while the RQ-170 and RQ-180 are being used for ISR purposes, according to open-source reporting,⁵⁸ many international development programs such as the Taranis and nEUROn are intended to produce strike platforms.⁵⁹ Similarly, the Defense Advanced Research Projects Agency (DARPA) Joint Unmanned Combat Air System (J-UCAS) – genesis of the X-47B carrier-capable technology demonstrator – and some concepts for the U.S. Navy’s Unmanned Carrier-Launched Airborne Surveillance and Strike (UCLASS) system include a penetrating strike capability in addition to ISR and electronic warfare capabilities.⁶⁰

In the years to come, UAVs may feature a number of even more sophisticated technologies. For example, DARPA’s Collaborative Operations in Denied Environment (CODE) program is designed to enable multivehicle control, both by expanding the number of systems that can be supervised by a single operator and by allowing those systems to “collaborate to find, track, identify, and engage targets” in a denied environment.⁶¹ This technology would additionally allow operators to employ swarming tactics to overwhelm adversary defense systems.⁶² DARPA is also exploring Distributed Battle Management (DBM) to ensure coordinated operations, guided by automated decision tools, in a communications-denied environment, as well as High Assurance Cyber Military Systems (HACMS), a program intended to protect systems from cyberhacking and hijacking.⁶³ Similarly, DARPA is exploring high-resolution, GPS-independent positioning, navigation, and timing systems that will allow for continued operations in a GPS-jammed environment.⁶⁴ Finally, stealthy combat drones may soon have the ability to conduct autonomous aerial refueling, further extending their operational reach and enabling deep strikes within an adversary’s territory.⁶⁵

Summary

While the United States is the only country known to operate stealth combat systems, a number of others – including Russia, Israel, China, India, France, Italy, Sweden, Spain, Greece, Switzerland, South Korea, and the United Kingdom – have active development programs. These systems represent the highest level of technological sophistication and, as such, are tightly controlled by indigenous producers. While current stealth combat systems may or may not have the range, endurance, or payload capacity of large, military-specific systems, they feature a number of low-observable characteristics that enable them to operate in environments with advanced integrated air defense systems.

Potential for Overmatch

While much research to date has focused on military UAVs,⁶⁷ hobbyist drones are often less discussed within a security context, though they perhaps hold the greatest potential for achieving technology overmatch against the United States in the near term. Indeed, hobbyist drones are growing increasingly sophisticated – offering autonomous flight, high-end ISR capabilities, and ever-expanding payload capacity, range, and endurance. They are also widely accessible to potentially disruptive actors and, because drones assembled from component parts generally do not have identifiable markings, could increase the difficulty of attribution if used in an attack. In addition, due to their size, construction material, and flight altitude, hobbyist drones are difficult to defend against if their presence in a particular area is unknown or unexpected.⁶⁸ These factors could in turn increase the likelihood that hobbyist drones – particularly those assembled by the operator, and thus not subject to manufacturer-installed geofencing – could be weaponized and autonomously deployed in a terrorist attack against civilians or in an IED-like capacity against patrolling military personnel.

While such systems may not appear sophisticated in a traditional military sense, ground-emplaced IEDs have caused thousands of American deaths in Iraq and Afghanistan and proved profoundly hard to defeat.⁶⁹ Drones will enable airborne IEDs that can actively seek out U.S. forces, rather than passively lying in wait. Indeed, low-cost drones may lead to a paradigm shift in ground warfare for the United States, ending more than a half-century of air dominance in which U.S. ground forces have not had to fear attacks from the air.⁷⁰ Airborne IEDs could similarly be used in a terrorist attack against civilians or in precision strikes against high-profile individuals or landmarks.

As autonomy and multivehicle control become more mature, it is also possible that an adversary could deploy swarming attacks of inexpensive, expendable drones against U.S. ships and bases.⁷¹ While this approach would produce a large, easily detectable radar cross-section, it would additionally complicate U.S. targeting. In this way, swarms of UAVs could be used to temporarily deny the United States access to airspace within a given area of operations or to overwhelm U.S. air defense systems for ships and bases.⁷² These approaches could enable an individual, non-state actor, or state to achieve capability overmatch against the United States.