How THOR hammers enemy drones
Two summers ago, amateur video captured this eye-popping explosion at a Ukrainian armory. The blast caused at least one death and destroyed roughly $1 billion of ammunition, damage on a remarkable scale considering it was caused by a single grenade-carrying drone. As the incident demonstrates, weaponized drones are a major emerging threat. Small drones can now carry surveillance technology and destructive cargo. They're difficult to bring down using kinetic weapons, posing a threat to military bases and civilian targets alike. Notably they're dangerous and cause confusion in the same airspace as commercial planes; consider the disruption at London’s Heathrow airport earlier this year when a drone sighting grounded departures for at least an hour.
As far as the military is concerned, drones pose at least two major threats. First, reconnoitering. “Drones can be used to spy on warfighting activities and assess our capabilities,” said Leidos expert Billy Schaefer. Second, attacking. “Even small drones can have armaments mounted to them,” Schaefer said, “…and they’re extremely difficult to detect, target, and attack.” One major emerging threat is drone behavior coordination, he said. “A worst-case scenario is a swarm attack…a large number of carefully orchestrated drones armed to attack a U.S. base, battalion, or any other target. If each of them had a grenade or C4 package on it, that’s a real threat. All of these threats are in play against U.S. forces.”
Traditional kinetic weapons like nets, bullets, and missiles have limitations against single-drone and swarm attacks, simply put, because it’s hard to hit a small moving target. Small drones are hard to see even at moderate distances and move quickly in all directions. Given the limitations of kinetic weapons, the Pentagon is looking to more effective technology, including directed energy. Over the summer, the Air Force Research Laboratory (AFRL) unveiled a new drone defense system called the Tactical High-power Operational Responder (THOR), a platform that brings down drones using microwave beams. These powerful waves, which travel at the speed of light, are an effective method against drones because they disrupt electronic components.
THOR is housed inside a unit roughly the size of a 20-foot shipping container, can be deployed quickly, and is designed to take out a large number of drones at once. It casts a wide net with invisible, inaudible electromagnetic wave pulses, dramatically simplifying drone targeting methodology. Think of the broad field of light from a flashlight with a much farther range. “As soon as you pull the trigger, it’s on,” Schaefer said. “If you lock onto your target, you’ve got it. You’re going to hit it. With the speed-of-light approach that you get with directed energy it’s a huge advantage.”
This solution is the first of its kind, and there were some significant scientific breakthroughs required for this to actually function.
Billy Schaeffer
Directed Energy Manager
Leidos and other contractors supported AFRL to develop THOR. Leidos provided scientific, engineering and technical support to develop its microwave emitter, or firing mechanism. “It’s a new approach to high-power microwave source design,” Schaefer said. “This particular approach has never been tried before. It’s more than an engineering exercise. The problems weren’t engineering problems. They were physics problems. This solution is the first of its kind, and there were some significant scientific breakthroughs required for this to actually function.”
Leidos has supported AFRL through R&D programs in directed energy for more than 30 years. THOR is a prototype that will be reviewed by the DoD before being deployed in the field. It was developed at Kirtland Air Force Base in Albuquerque, New Mexico, and was unveiled in a live demonstration to local reporters in June. Here are several press clippings from the event:
- The U.S. Air Force has a new weapon called THOR that can take out swarms of drones (The Verge)
- USAF directed-energy weapon ‘THOR’ can down swarms of drones simultaneously (TechSpot)
- Air Force Research Lab Unveils New HPM System (Los Alamos Daily Post)
- Kirtland AFB’s ‘THOR’ is dropping the hammer on drones (KRQE-13)
