skip to Main Content

What is it?
The Active Denial System (ADS) is a counter-personnel,
non-lethal, directed energy weapon. The ADS projects a
focused beam of millimeter waves to induce an intolerable
heating sensation on an adversary’s skin, repelling the
individual without causing injury. This capability will add
to the ability to stop, deter and turn back an advancing
adversary providing an option to lethal force. The ADS’
non-lethal capabilities are designed to protect the innocent,
minimize fatalities, and limit collateral damage.
The technology was originally developed by the Air Force
Research Laboratory and matured under the sponsorship
of the Department of Defense’s Joint Non-Lethal Weapons
Directorate (JNLWD). The ADS will provide our
warfighters an extraordinary new capability – a non-lethal
weapon with a range greater than traditional small arms.
How Does It Work?
Active Denial Technology produces millimeter waves at a
frequency of 95Ghz and uses an antenna to direct a
focused, invisible beam toward a designated subject.
Traveling at the speed of light, the energy strikes the
subject and only reaches a skin depth of about 1/64th of an
inch or the equivalent of three sheets of paper. It produces
a heat sensation that within seconds becomes intolerable
and forces the targeted individual to instinctively flee. The
sensation immediately ceases when the individual moves
out of the beam or when the operator turns off the system.
There is minimal risk of injury from the beam because of
the shallow penetration depth of energy at this short
wavelength, the safety features designed into the system,
and normal human instinctive reactions. These features
include a bore sighted sensor suite that allows the operator
to see the entire beam path and target area, and requires no
adjustments for ballistics or windage. In addition, ADS
incorporates computer systems (hardware and software)
that limit shot duration and beam power to achieve a safe
and effective non-lethal repel effect.
Scientific Research
A large portion of the investment has been devoted to
understanding the effects of this technology on the human
body. This effort was made to ensure the effects of
millimeter waves are well understood, and to ensure a
wide safety margin exists between operationally useful
levels of effects and those that may cause injury. The ADS
has been the subject of an extensive test program that has
been conducted in strict compliance with the procedures,
laws and regulations governing animal and human
research. The tests have been reviewed and approved by a
formal Institutional Review Board with oversight from
the Air Force Surgeon General’s Office.
An independent panel of non-governmental science and
medical experts also periodically reviewed and advised on
the planning aspects and results of the research and test
activities. In a 2004 review of the program, this
independent panel concluded there is low risk of serious
injury from exposure to the ADS beam. Additionally, the
panel concluded that the risk of thermal eye injury is low,
and that there was no evidence that millimeter wave
energy promotes or co-promotes cancer. A detailed report
of the study appears in the peer review journal,
Carcinogenesis (2001) 22:1701-1708.

The Air Force Research Laboratory’s Human
Effectiveness Directorate at Brooks City-Base, Texas,
conducted many years of successful and safe laboratory
testing. In 2000, testing began at Kirtland Air Force Base,
south of Albuquerque, New Mexico, using a full-scale
Active Denial Technology Hardware Demonstrator. It
enabled assessment of the potential military utility of the
System Evolution
The Active Denial Technology Hardware Demonstrator
(ADS System 0) represented the first integration of the key
technology elements such as the millimeter wave source,
cooling system, and antenna, among others. In 2001, ADS
System 0 successfully demonstrated that the technology
could achieve desired effects at distances beyond small
arms range, and set the stage for the next evolution of the
system, ADS System 1. This next step involved the
integration and packaging of all the system’s components
into a mobile, nearly militarized system. The configuration
chosen was the High Mobility Multi-purpose Wheeled
Vehicle (HMMWV). In 2002, the ADS System 1 was
placed under an Advanced Concept Technology
Demonstration (ACTD) program, a DoD process to
rapidly move mature technologies into the hands of the
war fighter for military evaluation.
Under the ACTD Program, the Air Force Research
Laboratory produced a HMMWV-mounted prototype,
which was used in a series of three Military Utility
Assessments (MUA) – Creech AFB in August 2005, Ft.
Benning in September 2005, and Eglin AFB in April 2006.
These MUAs tested the performance of the prototype in a
variety of simulated operational scenarios.
The prototype ADS System 1 is now in the Extended User
Evaluation phase, which will run throughout FY07. At the
same time, a modular version (ADS System 2) was
developed and is scheduled to be complete in Spring
2007. The ADS System 2 is designed to operate in higher
temperature environments and is able to operate at either a
fixed site or on the back of a tactically mobile truck. The
System 2 millimeter wave energy beam is identical to that
of System 1.
Organizations Involved
The ADS ACTD Program is being sponsored by the
Office of the Deputy Under Secretary of Defense for
Advanced Systems and Concepts, the Department of
Defense Joint Non-Lethal Weapons Directorate, and
the U.S. Joint Forces Command. The Air Force Research
Laboratory’s Directed Energy Directorate at
Kirtland Air Force Base, New Mexico, is the technical
manager and responsible for the ADS
prototype development. The Laboratory’s Human
Effectiveness Directorate at Brooks City-Base, Texas,
manages the human effects characterization research
and test program. The Air Combat Command at
Langley Air Force Base, Virginia, is the operational
manager and is leading the military services in
developing the concepts of operation and managing
the formal military utility assessment. The role of
transition manager is shared by Air Force’s
Electronic Systems Center at Hanscom Air Force
Base, Massachusetts and the Army’s Program
Manager for Directed Energy Applications at
Huntsville, Alabama.


Back To Top