The High Energy Laser Systems Test Facility (HELSTF) is located at White Sands Missile Range, New Mexico. HELSTF became operational on September 6, 1985 when the Air Force conducted the first Lethality and Target Hardening (LTH-l) program test for the Strategic Defense Initiative Organization (SDIO). HELSTF has been managed by the U.S. Army Space and Strategic Defense Command (USASSDC) since October 1990. Prior to that, the facility was under the command of Commander, White Sands Missile Range. Primary support for operation and maintenance of the SDC-managed facility is currently provided by Lockheed Engineering and Science Company (LESC). The Navy is responsible for the operation and maintenance of the MIRACL and the SEALITE Beam Director through its contractors, TRW and Hughes Aircraft.
HELSTF is designated as the Department of Defense (DoD) National Test Facility for high energy laser test and evaluation. HELSTF is the home of the Mid Infrared Advanced Chemical Laser (MIRACL), the United States' most powerful laser, which is a CW, megawatt class deuterium-fluoride laser operating in a band from 3.6 to 4.2 microns. In the more than ten years since operations began, HELSTF has supported a broad range of both laser and non-laser related test activities. High energy laser tests have included damage and vulnerability testing for all three uniformed services as well as materials and chemical research for industry and academia. HELSTF represents an approximate $800 million investment, with about $80 million of that in military construction funds.The Mid-Infrared Advanced Chemical Laser (MIRACL) was the first megawatt-class, continuous wave, chemical laser built in the free world. It is a deuterium fluoride (DF) chemical laser with energy spectra distributed among about 10 lasing lines between 3.6 and 4.2 microns wavelength. Since it first lased in 1980, it has accumulated well over 3000 seconds of total lasing time. It remains the highest average power laser in the US.
MIRACL operation is similar to a rocket engine in which a fuel (ethylene, C2H4) is burned with an oxidizer (nitrogen trifluoride, NF3). Free, excited fluorine atoms are one of the combustion products. Just downstream from the combustor, deuterium and helium are injected into the exhaust. Deuterium combines with the excited fluorine to give excited deuterium fluoride (DF) molecules, while the helium stabilizes the reaction and controls the temperature. The laser's resonator mirrors are wrapped around the excited exhaust gas and optical energy is extracted. The cavity is actively cooled and can be run until the fuel supply is exhausted. The laser's output power can be varied over a wide range by altering the fuel flow rates and mixture.
The laser beam in the resonator is approximately 21 cm high and 3 cm wide. Beam shaping optics are used to produce a 14 cm square beam shape which is propagated through the rest of the beam train. Diagnostics for evaluating the beam shape, absolute power and intensity profile are used on each firing of the laser. The beam can be directed to a number of different test areas or to the SLBD.
Congress canceled the Navy SEALITE program, a self-defense lethality demonstration using the Mid-Infrared Advanced Chemical Laser (MIRACL), in the fall of 1983 and directed the MIRACL be installed at HELSTF to support a variety of tests for DoD. The SEALITE Beam Director (SLBD) is mounted on top of Test Cell 1. It consists of a large aperture (1.8 meter) gimbaled telescope and optics to point the MIRACL or other laser beam onto a target. The high power clear aperture is 1.5 meters. The remaining 0.3 meters is normally reserved for a tracker using the outer annulus of the primary mirror. The system is extremely agile and capable of high rotation and acceleration rates. The SLBD weighs 28,000 pounds, of which 18,000 are on the movable portion. The SLBD can also be used as a sensor platform.
The telescope is capable of focusing from a minimum range of 400 meters to infinity. A suite of infrared and visible sensors on the top of the gimbal (off axis from the HEL aperture) is used to acquire and track the target. These sensors look through a 40 cm telescope that can focus over the same range as the SLBD telescope and also correct for parallax between the two lines of sight. Boresight between the SLBD telescope and the sensor is maintained by an automatic laser alignment system. In addition, an aperture sharing element in the high power beam path makes it possible to track a target through the full 1.5 meter telescope aperture even when the high power beam is propagating.
These elements have been combined into an integrated system that can acquire and track targets at extended ranges, accept a very high energy beam, focus and aim the beam on a moving target, and keep this beam at the same position as long as necessary to destroy or disable the target. The SLBD has successfully engaged five BQM-34 drones as well as a supersonic Vandal missile, all at tactically significant ranges.
In addition to directing the high energy laser beam, the HELSTF SLBD has been used very successfully to passively track and image missiles in flight. The inherently precise pointing of the device and its ability to track very high speed targets make it an ideal platform for capturing in-flight imagery. The SLBD has been used as a sensor platform for tracking and imaging a number of Theater Missile Defense (TMD) launches and intercepts, including LANCE, ERINT, and LEAP. A 1000 frame-per-second, digital, infrared camera has been used to collect two-dimensional intercept measurements from targets and interceptors at over Mach 6 closure rates. Calibrated infrared sensors placed in the SLBD's optical train have been used to collect IR imagery for plume and hardbody thermal characterization.
SENSOR WAVE- FIELD OF ARRAY SIZE FRAME RATE APERTURE BAND VIEW LWIR 8-12 m 700 rad 128 x 128 up to 1000 1.5 m fps MWIR 3-5 m 700 rad 128 x 128 up to 1000 1.5 m fps FLIR 8-12 m 4 x 5 scanned 60 Hz/264 40 cm mrad lines NFOV TV visible 5 x 6.5 510 x 492 60 Hz/264 40 cm mrad lines Wide FOV visible 6.6 x 8.8 510 x 492 30 Hz 90 mm mrad Wide FOV AMBER 3-5 m 12 mrad 128 x 128 up to 109 50 mm Hz MIT High Frame visible 100 rad 64 x 64 2000 Hz 1.5 m Rate to 1 mrad