Low‑Cost Counter‑Drone Net

A hostile drone can be stopped without firing a missile if another drone gets close enough to foul its flight. Naval Postgraduate School researchers say they built that kind of counter-drone tool around a low-cost payload and an AquaQuad aircraft. (nps.edu) The Naval Postgraduate School story, published April 20, 2026, says the team tested the concept at Camp Roberts in California in May 2022 against two small drones: a Parrot Bebop 2 and a Skydio 2+. In that demonstration, an AquaQuad launched from the far end of McMillan Airfield and engaged the targets from 1,000 meters and 1,824 meters away. (nps.edu) The school says the payload is called the Detachable Drone Hijacker, or DDH, and that it weighs 457 grams, draws up to 492 milliamps, and costs about $250. Instead of blasting a wide area, it uses a de-authentication attack aimed at drones using the IEEE 802.11 Wi‑Fi standard, cutting the link between the aircraft and its controller. (dvidshub.net) AquaQuad is the carrier in this setup: a Naval Postgraduate School quad-rotor aircraft designed to launch from water or land and stay out for long surveillance missions. A 2020 Naval Postgraduate School thesis described it as a small unmanned aerial system that pairs solar power with a quadrotor design for persistent, autonomous intelligence, surveillance, and reconnaissance work. (apps.dtic.mil) The pitch is cost math as much as engineering. A 2024 U.S. Naval Institute essay on drone swarms said commercial camera drones can cost a few hundred dollars and put defenders in a bind when the alternative is spending hundreds of thousands of dollars on a short-range surface-to-air missile. (usni.org) That mismatch has pushed militaries toward cheaper countermeasures, including electronic warfare, guns, lasers, microwaves, and interceptor drones. The same U.S. Naval Institute essay argued that defenders need economical answers because large numbers of small drones can exhaust missile stocks quickly. (usni.org) The Naval Postgraduate School says U.S. Marine Corps Maj. Christian Thiessen and computer scientist Britta Hale developed DDH over about five years, from early research to field tests and patenting. The school says the patent was awarded on May 13, 2025, and federal patent records list it as “Detachable drone hijacker and/or jammer method, apparatus and system.” (nps.edu) (patentsgazette.uspto.gov) The project has moved past the lab. Naval Postgraduate School says Thiessen presented DDH at the school’s Reverse Pitch event in July 2025, and the technology has since been licensed to a U.S. defense company for further development. (nps.edu) (fleetwerx.org) The closing argument from the researchers is simple: if cheap drones are becoming routine threats, the interceptors cannot all be exquisite. Their answer is a small payload on a reusable drone, built to break an attacker’s control link before the defender burns through far costlier weapons. (nps.edu)