Military turns HAARP into a radar to watch Alaska’s skies

The U.S. military has used HAARP, the giant research antenna field in Alaska long at the center of conspiracy theories, as the transmitter for an experimental radar that detected aircraft beyond the horizon by bouncing signals off the upper atmosphere.

Military personnel, scientists and international partners carried out the live-fly test from Sept. 7 to 11, 2026, in the final event of a three-year Arctic air domain awareness experiment series, Alaskan Command said. The goal was to see whether an existing high-frequency transmitter, paired with a new low-cost receiver array, could spot aircraft beyond the reach of Alaska’s current long-range radar sites.

Initial results show the system made full skywave detections of aircraft, meaning it picked them up beyond line of sight, and matched them with the known positions of test flights, according to Alaskan Command. The team met or exceeded its test objectives, and detailed analysis of the data is still underway.

HAARP, the High Frequency Active Auroral Research Program facility near Gakona in eastern Alaska, covers 33 acres with 180 crossed-dipole antennas that can transmit 3.6 megawatts of radio energy. Originally funded by the U.S. Air Force, U.S. Navy and DARPA to study the ionosphere, it has been run by the University of Alaska Fairbanks since 2015. In the experiment, it served as a high-power illuminator, beaming signals up toward the ionosphere, which reflected them back down over Alaska’s maritime approaches.

A receiver array at Cold Bay, near the tip of the Alaska Peninsula, developed by the nonprofit research organization MITRE, listened for the echoes from aircraft flying over the Gulf of Alaska and the Bering Sea. MITRE designed and ran the field experiment with government, scientific and operational partners.

“Working with operational units allows us to compare the experimental observations with known aircraft positions and assess where this approach could help address gaps in air surveillance,” said Dr. Carolyn Stwertka, chief scientist at Alaskan Command.

To give researchers a reliable reference, several U.S. Air Force aircraft flew as cooperative targets with known positions: an E-3 Sentry airborne warning and control aircraft from the 962nd Airborne Air Control Squadron, HC-130J Combat King II search and rescue planes from the 211th Rescue Squadron, and KC-135 Stratotankers from the 168th Air Refueling Wing.

The effort brought together Alaskan Command, U.S. Northern Command, the Air Force Research Laboratory and Defence Research and Development Canada, along with other scientific and operational partners.

Over-the-horizon radar of this kind could help fill gaps across Alaska, where huge distances, harsh weather and limited infrastructure make it difficult to keep watch over every approach. Russian military aircraft regularly fly near Alaska’s air defense identification zone, prompting intercepts by U.S. and Canadian fighters under NORAD, and in July 2024 Russian and Chinese bombers flew together near Alaska for the first time. Canada, which shares NORAD with the United States, plans to field its own over-the-horizon radars to watch the northern approaches as part of its NORAD modernization.

The September flights concluded the live-fly portion of the experiment series. Alaskan Command did not say whether the military plans to turn the concept into an operational system.