US Non-Lethal Weapon Work Revealed

US Non-Lethal Weapon Work Revealed: Freedom-of-information research project Public Intelligence has published the Pentagon's 2011 Non-Lethal Weapons Reference Book, which includes in its listing details of several prototype, developmental and conceptual versions of Raytheon's Active Denial System "heat ray" (hat-tip to The Register).

The document also lists several other high-tech methods of targeting personnel and material non-lethally, the most inventive of which has to be "laser-based flow modification".

All graphics: DoD

Intended to divert aircraft from restricted areas, this uses a pulsed laser aimed at the leading edge of the target aircraft's wing to modify airflow over the control surfaces to adjust drag and lift. This would externally apply steering forces to divert the aircraft from its flightpath. The document says the technique is at the conceptual stage (defined as TRL 4 or less), with the work led by the DoD's Joint Non-Lethal Weapons Directorate (JNLWD).

Also at the conceptual stage within the JNLWD is a high-power microwave (HPM) payload for an unmanned aircraft, designed to stop or disable small boats by interfering with the electrics to stop their engines. The HPM payload would have a long-range capability to protect naval forces and ports against swarming boat attacks.

Non-lethal systems in development (defined as TRL 5 or higher) include a Humvee-mounted RF vehicle stopper, which would use a high-power microwave beam to enforce a keep-out zone by knocking out vehicle engines. More sinister sounding is a conceptual technique called "nano-second electrical impulses", which would disable individuals for extended periods using an electrical waveform that causes "electro-muscular incapacitation" - described as "loss of voluntary muscle control by electrical stimulation".

In addition to two prototype Active Denial Systems (ADS) that have been produced, the document lists a conceptual next-generation system that is smaller, lighter and cheaper and capable of being integrated on to armored vehicles for force protection and crowd control.


ADS is a directed-energy weapon that fires a high-power millimeter-wave beam to heat up water and fat molecules in the body, causing intense pain but without damaging flesh. According to the document, the US Army is working on a solid-state version that would replace the current gyrotron transmitter and bulky antenna with an active array that would generate multiple beams to target several people simultaneously. The document also says the US Air Force continues conceptual work on an airborne version of ADS.