In recent years, small drones have made their way onto battlefields where they’ve been used to surveil US forces or drop bombs on them, prompting the US military to develop new ways to take them down. This week, the US Air Force unveiled a new tool that can be stationed at bases around the world: a high-powered microwave system called Tactical High Power Microwave Operational Responder (THOR), which is designed to protect bases against swarms of drones.

The Air Force Research Laboratory at the Kirtland Air Force Base in Albuquerque, New Mexico, developed the system, which uses short bursts of high-powered microwaves to disable unmanned aerial vehicles (UAVs). According to local TV station KRQE, the system was developed quickly (18 months) for about $15 million. It runs off of a generator and is stored in a shipping container, meaning it can be transported almost anywhere and set up within a couple of hours.

The Air Force began testing THOR against short-range targets earlier this spring, while another system, the Counter-Electronic High-Power Microwave Extended-Range Air Base Air Defense (CHIMERA) is designed to hit things at medium to long ranges. That system is expected to be delivered sometime next year.

The military predicts that a major problem will be swarms of drones operating in concert when it wouldn’t matter if one or two are taken down. This system is effectively designed to take out a large number of drones all at once and has a further range than bullets or nets. THOR program manager Amber Anderson says that the system “operates like a flashlight,” and that anything caught in the beam “will be taken down ... in the blink of an eye.”

Taking out a drone is a difficult proposition: they’re small and difficult to hit with a gun, and if they’re flying over people, there’s a risk that they could be injured by falling debris or pieces of drone. That hasn’t stopped people from trying a variety of methods for taking them down, from conventional defensive systems to nets, eagles, and even shotgun-wielding drones. The US Army has begun looking for similar systems. It invested in a microwave weapon built by Lockheed Martin back in August 2018, while other parts of the Department of Defense have been testing other defensive systems, like lasers, which could be used against drones or missiles.