Why This Issues

There’s a surge in curiosity in directed power weapons from a number of nations—together with the U.S.—primarily for counter drone missions. These weapons use electromagnetic power to trigger results starting from deterrence to destruction. They provide capabilities that standard weapons might not, however challenges have to this point prevented widespread operational use.

The Expertise

What’s it? Directed power weapons (DEW) use concentrated electromagnetic power to fight enemy forces and property. These weapons embrace excessive power lasers and different excessive energy electromagnetics—akin to millimeter wave and excessive energy microwave weapons. Not like weapons that fireplace bullets or missiles, DEWs can reply to a menace in several methods. For instance, they will briefly degrade electronics on a drone or bodily destroy it. See our 2022 Highlight for extra data on counter-drone know-how.

How does it work? Every kind of DEW makes use of a distinct area of the electromagnetic spectrum (see fig. 1). This spectrum describes all the sorts of sunshine—together with these the human eye can not see—and classifies them in line with wavelength. Various kinds of electromagnetic power have completely different properties. For instance, the wavelength impacts what the directed power can penetrate—akin to metallic or human pores and skin.

Determine 1. Location of directed power weapons on the electromagnetic spectrum.

All DEWs emit power on the pace of sunshine, and are sometimes mentioned when it comes to their energy output—the quantity of electromagnetic power transferred over time. Whereas DEWs use electromagnetic power much like on a regular basis gadgets, akin to family microwaves, their energy output is vastly larger, as described beneath.

Excessive power lasers produce a really slim beam of sunshine, normally within the infrared to seen area, and are sometimes used on one goal at a time. The beam could be pulsed or steady, producing an influence output of at the least 1 kilowatt. This output is 200,000 instances larger than a typical laser pointer and is able to melting metal.

Millimeter wave weapons have wavelengths between 1 and 10 millimeters and generate greater than 1 kilowatt of energy. Millimeter wave weapons have a bigger beam dimension than excessive power lasers and due to this fact can have an effect on a number of targets without delay.

Excessive energy microwave weapons produce microwaves, which have longer wavelengths than excessive power lasers and millimeter wave weapons. These weapons can produce greater than 100 megawatts of energy, which is sort of 150,000 instances extra highly effective than the common family microwave. Like millimeter wave weapons, they will additionally have an effect on a number of targets due to their bigger beam dimension.

Every DEW can produce a spread of results from nonlethal to deadly, relying on elements such because the time on track, the space to the goal, and even the a part of the goal on which the DEW is targeted. DEWs can use this vary of results to graduate responses to a menace. A graduated response may begin with briefly stopping use of an asset or its entry to an space and enhance to destruction of the asset if essential (see fig. 2).

Determine 2. Examples of graduated responses utilizing directed power weapons.

DEWs can deny entrance to an space or forestall enemy forces or property from functioning inside an space. DEWs used for denial don’t trigger long-term injury to targets, and when enemy forces or property depart the realm, they sometimes regain perform or the impact is mitigated. For instance, the Division of Protection’s (DOD) Energetic Denial System makes use of millimeter waves that work together with the water and fats molecules in an individual’s pores and skin to create a heating sensation. Throughout testing, the discomfort persuaded people to maneuver away from the realm.

DEWs also can degrade the efficacy of an enemy’s property. For instance, excessive power lasers can briefly overwhelm an individual or a sensor’s capacity to see or sense by emitting a glare—known as dazzling. Dazzling can act as a non-verbal warning earlier than resorting to elevated power.

If a larger quantity of power is required, DEWs also can injury or destroy enemy property. To do that, a excessive power laser can emit electromagnetic power with a wavelength the goal materials absorbs most successfully, melting the fabric. The laser may give attention to a sensor and injury a drone, or give attention to a gasoline tank or battery and destroy it.

How mature is it? DEWs vary in maturity from analysis initiatives to prototypes examined within the subject. DOD named DEWs as a know-how vital to enabling the 2018 Nationwide Protection Technique and reported spending about $1 billion yearly for the final 3 years on analysis and improvement. The U.S. army has examined a wide range of DEW prototypes since 2014, primarily for counter-drone missions. For instance, the Air Pressure’s prototype Tactical Excessive Energy Microwave Operational Responder (THOR) not too long ago accomplished 2 years of testing. DOD is researching methods to extend the facility output of DEWs to have interaction extra highly effective targets—like missiles. Nevertheless, as GAO not too long ago reported, the U.S. army faces challenges bridging the hole between DEW improvement and acquisition, probably limiting widespread operational use.

Why now? DEW analysis and improvement has been ongoing for many years in lots of international locations—together with the U.S.—and is at the moment experiencing a surge worldwide. This surge stems partially from advances in know-how and a need to keep up competitiveness on the battlefield. Technological improvements, akin to the event of smaller lasers which can be safer to function, allow trendy DEWs to be far more transportable and sensible. For instance, a four-wheel all-terrain automobile can now maintain a excessive power laser highly effective sufficient to wreck drones. The U.S. and 30 different nations are growing DEWs, most for counter-drone missions, in line with a 2021 Air Pressure report.

Alternatives

• Complement to standard weapons. DEWs use power fired on the pace of sunshine, making them sooner and probably more cost effective per shot than missiles. Some DEWs have just about limitless ammunition and might fireplace so long as they’ve energy.
• Ease of graduated response. DOD can tailor DEWs to satisfy mission wants from nonlethal to deadly responses. For instance, the longer a laser is targeted on track, the extra injury or destruction will happen.
• Advancing different makes use of. Analysis and improvement for DEWs may additionally profit civilian makes use of. For instance, the event of upper power lasers may assist initiatives that use directed power to move or “beam” energy to distant and deprived places.

Challenges

• Technological limitations. DEWs are typically much less efficient the farther they’re from the goal, and atmospheric situations and cooling necessities can restrict their effectiveness. For instance, fog and storms can cut back laser beam vary and high quality.
• Battlefield use. Choices about how and when to make use of DEWs or standard weapons could also be difficult. For instance, wider beam DEWs, akin to excessive energy microwave or millimeter wave weapons, have an effect on all property in an space, whether or not pal or foe. 
• Moral and well being issues. Though there are probably related worldwide legal guidelines and pointers, their applicability to DEWs just isn’t at all times effectively outlined. Uncertainty round long-term well being results of DEWs on folks both deliberately or unintentionally uncovered to directed power has led to issues relating to the ethics of utilizing DEWs.

Coverage Context and Questions

• Because the know-how matures, what actions may policymakers take to assist bridge the hole between DEW improvement and acquisition?
• What actions may policymakers take to make sure there may be applicable steerage for utilizing DEWs because the know-how matures?
• What are the trade-offs of utilizing nonlethal DEW applied sciences earlier than potential well being results are totally understood?

For extra data, contact: Brian Bothwell at (202) 512-6888 or bothwellb@gao.gov.