Within Kill Effect
Why a Falling Drone Does Not Prove the Kill
A falling drone does not reveal whether THOR caused a reboot, radio loss, sensor upset, or permanent electronics damage.
On this page
- What public test footage can and cannot show
- Failure modes that look the same from outside
- What telemetry and teardown evidence would add
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Introduction
When footage shows a drone suddenly dropping from the sky after engagement by the Air Force Research Laboratory’s THOR high-power microwave system, the video alone rarely reveals what actually happened inside the aircraft. That is a central challenge in assessing THOR’s effectiveness. A falling drone demonstrates that something disrupted flight, but it does not distinguish between a temporary software crash, a communications failure, a sensor malfunction, a flight-controller reboot, or permanent electronic damage. Public descriptions of THOR emphasise that it creates a “counter-electronic effect” and disables drone electronics, yet they do not disclose the specific failure pathways produced during tests. [Air Force Research Laboratory]afresearchlab.comAir Force Research LaboratoryTACTICAL HIGH POWER OPERATIONAL RESPONDER…Sep 16, 2019 — The system uses high power microwaves to cause a…
This gap matters because different failure mechanisms imply very different military capabilities. A drone that can be recovered and restarted after landing represents a different outcome from one whose electronics have been irreversibly damaged. From external video footage, however, both outcomes can appear nearly identical.
What Public Test Footage Can and Cannot Show
Most publicly released THOR material focuses on observable outcomes: drones cease controlled flight, drift, descend, or crash. AFRL descriptions consistently state that THOR uses high-power microwaves to disable drone electronics and can engage multiple targets simultaneously. They do not provide the telemetry, component-level diagnostics, or post-test forensic analysis needed to determine exactly what failed. Air Force Research Laboratory+2Air Force Research Laboratory [afrl.af.mil]afrl.af.milarmy partners with air forces thor for base defenseAir Force Research LaboratoryArmy partners with Air Force's THOR for base defenseFeb 23, 2021 — THOR is a prototype directed energy weapo…
A video camera records only the drone’s external behaviour. It cannot directly show:
- Whether the flight computer reset itself.
- Whether the radio link was disrupted.
- Whether GPS reception was corrupted.
- Whether motor controllers stopped responding.
- Whether sensors began reporting invalid data.
- Whether semiconductor components suffered permanent damage.
The limitation is not unique to THOR. Government and industry discussions of high-power microwave counter-drone systems frequently note that electromagnetic effects can range from temporary degradation to lasting hardware damage. The visible result may still be a drone falling from the sky. [GAO]gao.govgao 23 106717Science & Tech Spotlight: Directed Energy Weapons25 May 2023 — These weapons include high energy lasers and other high power electroma…
This contrasts with many kinetic or laser engagements. A missile strike may leave fragmentation damage, while a laser can sometimes leave visible burn marks. Microwave effects occur inside electronic systems, often without obvious external signatures. [GAO]gao.govgao 23 106717Science & Tech Spotlight: Directed Energy Weapons25 May 2023 — These weapons include high energy lasers and other high power electroma…
Why Different Failure Modes Look the Same from Outside
A multicopter stays airborne because several electronic subsystems operate together continuously. If any one of them fails, the aircraft may exhibit nearly identical flight behaviour.
Flight Controller Reboot
Many drones depend on a central flight computer that stabilises the aircraft hundreds of times per second. If electromagnetic energy causes the processor to reset, the drone can immediately lose stabilisation and fall.
From external footage, this can look exactly like catastrophic destruction. Yet a rebooted controller may later function normally once power is restored. High-power microwave effects are known to include temporary electronic upset as well as more severe damage. [Defence Finance Monitor]defencefinancemonitor.comDefence Finance MonitorNon-Kinetic Counter-UAS with High Power Microwave8 Dec 2025 — The effects of an HPM hit on a drone can range from…
Communications Loss
A microwave-induced disruption of radios or data links could trigger a failsafe response. Depending on programming, the drone might attempt to hover, land, return home, or simply descend.
To an observer watching a distant engagement video, that descent can appear indistinguishable from a permanent kill. The aircraft may be responding to software instructions rather than suffering irreversible damage.
Sensor Failure
Modern drones depend on GPS receivers, inertial measurement units, compasses, altimeters, and other sensors. If sensor data becomes unreliable, the aircraft may lose orientation or navigation capability.
Again, the visible result may simply be erratic flight followed by a crash. Without access to onboard data logs, it is difficult to identify which sensor failed first.
Motor or Power-System Disruption
Electronic speed controllers and power-management circuits are also vulnerable to electromagnetic disturbances. A motor stopping unexpectedly can produce a rapid descent similar to that caused by a failed flight computer.
From a ground-based camera, both scenarios often produce the same observable sequence: stable flight, sudden instability, then impact.
The Problem of “Upset” Versus “Burnout”
One of the most important distinctions in high-power microwave effects is the difference between electronic upset and electronic burnout.
An upset refers to temporary malfunction. Electronics may freeze, reset, generate incorrect outputs, or stop responding before later recovering. Burnout refers to permanent physical damage to components or circuits. Analysts of microwave counter-UAS systems frequently describe both outcomes as plausible results of electromagnetic attack. [Defence Finance Monitor]defencefinancemonitor.comDefence Finance MonitorNon-Kinetic Counter-UAS with High Power Microwave8 Dec 2025 — The effects of an HPM hit on a drone can range from…
The challenge is that both outcomes can generate the same visible evidence during a test. Consider two drones:
- Drone A experiences a processor reset and falls.
- Drone B suffers irreversible semiconductor damage and falls.
The crash video is nearly identical. The operational significance is not.
Drone A might be repairable within minutes. Drone B may require replacement electronics. Without internal examination, observers cannot tell which occurred.
This is one reason public THOR demonstrations do not fully resolve debates about kill mechanisms. They demonstrate operational effect, but not necessarily the underlying failure pathway.
Swarm Tests Make Attribution Even Harder
THOR’s main attraction is its ability to affect multiple drones simultaneously rather than engaging one target at a time. AFRL repeatedly highlights this counter-swarm role. U.S. Air Force+2Air & Space Forces Magazine [af.mil]af.milrls thor hammers drones in new video animationAir ForceAFRL's THOR hammers drones in new video animationJun 16, 2021 — High energy lasers kill one target at a time, and high powered m…
In swarm footage, multiple aircraft may begin descending within seconds of one another. That visual pattern confirms that the engagement had an effect across the group, but it complicates diagnosis.
Different drones within the same swarm may experience different internal failures because electromagnetic coupling depends on numerous factors, including orientation, wiring layout, shielding, antenna placement, and component design. A drone facing the emitter may respond differently from another flying nearby. Research and technical analyses of high-power microwave effects consistently emphasise that coupling into electronics is highly dependent on target characteristics. [arXiv]arxiv.orgA Multi-physics Simulation Framework for High-power Microwave Counter-unmanned Aerial System Design and Performance EvaluationFebrua…
As a result, a swarm video may show a common outcome—multiple falling drones—even if the underlying causes vary from aircraft to aircraft.
What Telemetry and Teardown Evidence Would Add
To move beyond visual impressions, investigators would need evidence from inside the drone.
Useful telemetry could include:
- Flight-controller error logs.
- Processor reset records.
- Sensor health reports.
- Radio-link status information.
- Power-system diagnostics. [arxiv.org]arxiv.orgA Multi-physics Simulation Framework for High-power Microwave Counter-unmanned Aerial System Design and Performance EvaluationFebrua…
- GPS reception history.
- Motor-controller fault messages.
Such data could reveal whether the aircraft experienced a software upset, communications loss, navigation failure, or hardware fault before impact.
Physical teardown analysis would add another layer of evidence. Engineers could inspect:
- Burned semiconductor devices.
- Damaged power regulators.
- Failed radio-frequency components. [reddit.com]reddit.comRadio Frequency Directed Energy Weapon successfully…RFDEWs are a type of directed energy weapon that neutralises threats by emitting h…
- Corrupted memory devices.
- Intact systems that simply rebooted.
This type of forensic evidence is routinely more informative than crash footage alone when assessing electromagnetic effects.
Why the Visual Evidence Remains Ambiguous
The core difficulty is that THOR is designed to affect electronics rather than produce visible structural damage. Public information confirms the intended counter-electronic nature of the weapon and demonstrates that drones can be disabled rapidly, including in swarm scenarios. Air Force Research Laboratory+2Air Force Research Laboratory [afresearchlab.com]afresearchlab.comAir Force Research LaboratoryTACTICAL HIGH POWER OPERATIONAL RESPONDER…Sep 16, 2019 — The system uses high power microwaves to cause a…
What public footage generally proves is that a drone lost effective flight capability after engagement. What it does not prove is whether THOR caused a reboot, radio failure, sensor upset, software crash, temporary electronic disruption, or permanent component damage.
For that reason, a falling drone is compelling evidence that an engagement occurred, but it is not, by itself, evidence of a specific kill mechanism. The most important clues lie in telemetry, diagnostics, and post-flight forensic examination—information that is rarely released alongside public demonstration videos. [GAO+2Air Force Research Laboratory]gao.govgao 23 106717Science & Tech Spotlight: Directed Energy Weapons25 May 2023 — These weapons include high energy lasers and other high power electroma…
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First published 1990. Subjects: Microwave devices, Microwaves, Microwave circuits, open_syllabus_project, Dispositif à micro-ondes.
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Endnotes
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Source: gao.gov
Title: gao 23 106717
Link: https://www.gao.gov/products/gao-23-106717Source snippet
Science & Tech Spotlight: Directed Energy Weapons25 May 2023 — These weapons include high energy [lasers]({{ 'lasers/' | relative_url }}) and other high power electroma...
Published: May 2023
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Source: gao.gov
Link: https://www.gao.gov/assets/830/825926.pdfSource snippet
Directed Energy WeaponsHigh power microwave weapons produce microwaves, which have longer [wavelengths]({{ 'wavelengths/' | relative_url }}) than high energy lasers and millime...
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Title: rls thor hammers drones in new video animation
Link: https://www.af.mil/News/Article-Display/Article/2658386/afrls-thor-hammers-drones-in-new-video-animation/Source snippet
Air ForceAFRL's THOR hammers drones in new video animationJun 16, 2021 — High energy lasers kill one target at a time, and high powered m...
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Source: arxiv.org
Link: https://arxiv.org/abs/2602.08477Source snippet
A Multi-physics Simulation Framework for High-power Microwave Counter-unmanned Aerial System Design and Performance EvaluationFebrua...
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Directed Energy Weapons: DOD Should Focus on...Apr 17, 2023 — The Department of Defense (DOD) is currently developing directed energy we...
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Title: Epirus Leonidas: High-Power Microwave for Counter-Electronics
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US Air Force Shuts Down Drone with Unbelievable New Technology! | Microwave Weapon...
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Source: youtube.com
Link: http://www.youtube.com/watch?v=XRnbuSaBR1ISource snippet
AFRL THOR [drone swarm]({{ 'swarm-limits/' | relative_url }}) demonstration footage THOR (Tactical High-power Operational Responder) Destroys [Swarms]({{ 'swarms/' | relative_url }}) of Enemy Drone...
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Source: afresearchlab.com
Link: https://afresearchlab.com/counter-swarm-high-power-weapon/Source snippet
Air Force Research LaboratoryTACTICAL HIGH POWER OPERATIONAL RESPONDER...Sep 16, 2019 — The system uses high power microwaves to cause a...
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Title: army partners with air forces thor for base defense
Link: https://www.afrl.af.mil/News/Article/2512426/army-partners-with-air-forces-thor-for-base-defense/Source snippet
Air Force Research LaboratoryArmy partners with Air Force's THOR for base defenseFeb 23, 2021 — THOR is a prototype directed energy weapo...
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Title: Air Force Research Laboratory AFRL’s THOR hammers drones in new video animation
Link: https://www.afrl.af.mil/News/Article-Display/Article/2649787/afrls-thor-hammers-drones-in-new-video-animation/Source snippet
Air Force Research LaboratoryAFRL's THOR hammers drones in new video animation - USAFJun 8, 2021 — High energy lasers kill one target at...
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Source: defencefinancemonitor.com
Link: https://www.defencefinancemonitor.com/p/non-kinetic-counter-uas-with-highSource snippet
Defence Finance MonitorNon-Kinetic Counter-UAS with High Power Microwave8 Dec 2025 — The effects of an HPM hit on a drone can range from...
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Title: Air & Space Forces Magazine THOR Hammers Drone Swarm with High-Power Microwaves
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Air & Space Forces MagazineTHOR Hammers Drone Swarm with High-Power MicrowavesMay 19, 2023 — The Air Force Research Laboratory's directed...
Published: May 19, 2023
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Source: afrl.af.mil
Title: enemy drone operators may soon face the power of thor
Link: https://www.afrl.af.mil/News/Article-Display/Article/2339175/enemy-drone-operators-may-soon-face-the-power-of-thor/Source snippet
“THOR is essentially a high-powered electromagnetic source that we put together...Read more...
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Source: afresearchlab.com
Link: https://afresearchlab.com/wp-content/uploads/2019/09/AFRL_THOR_FS_0122.pdfSource snippet
COUNTER-SWARM HIGH POWER WEAPONThe system uses high power microwaves to cause a counter electronic effect. A target is identified, the si...
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Source: af.mil
Title: Empowered Airmen
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Accelerate Change: Empowered AirmenNov 16, 2023 — Tactical, High-power, Operational, Responder, known as THOR, is a high power microwave...
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High-power Operational ResponderA high-powered microwave counter drone weapon, stands ready to demonstrate its effectiveness against a sw...
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Link: https://www.usfk.mil/What-We-Do/Exercises/Freedom-Shield/?dvpTag=Thor&videoid=904340Source snippet
Tactical High-power Operational ResponderTactical, High-power, Operational, Responder, known as THOR, is a high power microwave counter-d...
Additional References
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(PDF) Research on high power microwave weaponsThis structured narrative review analyses how High-Power Microwave (HPM) Directed Energy We...
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Link: https://www.researchgate.net/publication/401596360_Shaping_Modern_Warfare_The_Strategic_Role_of_High-Power_Microwave_Directed_Energy_Weapons_in_Multi-Domain_OperationsSource snippet
The Strategic Role of High-Power Microwave Directed...8 Mar 2026 — The paper compares HPM DEWs with high-energy laser (HEL) systems alon...
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AFRL's THOR Tracks and Disables Drone Swarm"Numerous drones were flown to simulate a swarm attack, and using its wide beam, high peak pow...
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Meet THOR: AFRL's Counter-Drone that Tracks and...THOR is a high-power microwave counter-drone weapon that the Air Force Research Lab ha...
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Phaser High-Power Microwave System | RaytheonDefending at the speed of light. The Phaser high-power microwave system uses directed energy...
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Radio Frequency Directed Energy Weapon successfully...RFDEWs are a type of directed energy weapon that neutralises threats by emitting h...
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THOR: AFRL Electromagnetic counter-swarm drone weaponTHOR is a portable counter-UAS system, capable of destroying swarms of drones at spe...
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Epirus' Leonidas Demonstrates Successful Use of High-...13 Jan 2026 — Leonidas is the first EW-based counter-UAS technology to demonstra...
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Disruption to Destruction Assessing theby K Karcz · Cited by 2 — High-Power Microwave (HPM) sources in remotely interacting with aerial v...
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