Pentagon authorizes DHS to test heat ray weapon for US-Mexico border

The Pentagon has authorized the Department of Homeland Security (DHS) to test the Active Denial System (ADS), a military-grade heat ray, for potential use along the US-Mexico border. A memorandum signed by Defense Secretary Pete Hegseth in September 2026 permits the testing and development of procedures for the device, which the Department of Defense will provide on a seven-month loan.

The ADS is a nonlethal directed-energy weapon that utilizes millimeter waves to interact with water and fat molecules in human skin. This creates an intense, burning sensation described by military officials as similar to opening a hot oven, designed to trigger an instinctive urge to flee the area. While the beam can reach targets nearly a kilometer away, the resulting tingling sensation typically lasts between 10 and 15 minutes depending on exposure.

While the DHS request did not specify exact testing locations or deployment methods, officials have previously discussed using the technology for crowd dispersal at the southern border.