Air Force Engineers Mix Laser Fuel

KIRTLAND AIR FORCE BASE, N.M., Jan. 22 -- Airborne-laser (ABL) engineers have successfully prepared and assessed a 1200-gallon batch of chemicals that help make up the delicately balanced formula necessary to create a laser beam capable of destroying a ballistic missile, Col. Ellen Pawlikowski, Kirtland-based ABL program director, said recently.

The event occurred on Dec. 18 at the ABL facility at Edwards Air Force Base, Calif., two weeks after 4,400 gallons of hydrogen peroxide were delivered to the ABL’s chemical mixing facility.

"We’re very excited about this batch because it is the initial step taking us to first light," said Col. Pawlikowski, referring to the production of a laser beam from the chemical oxygen iodine laser (COIL) modules that will be installed on ABL’s first aircraft, YAL-1A.

Although the precise formula is a secret, Col. Pawlikowksi said the batch was a mixture of hydrogen peroxide and potassium hydroxide, a salt that enhances and sustains the chemical reaction inside the megawatt-class COIL, ABL’s killer laser.

ON THE NOSE: The nose of an old 747, rescued from a salvage yard, protrudes through the exterior wall of the airborne laser's (ABL) system integration lab at Edwards Air Force Base, Calif. Engineers are using the hulk as a platform to build and test the chemical oxygen iodine laser (COIL), the system that produces the megawatt-class beam needed to destroy a ballistic missile. In the background is another airborne laser facility, the ground-pressure recovery assembly, a hollow sphere needed to emulate an altitude of 40,000 feet so the COIL can be tested at the ABL's nominal operational altitude. (Photo: US Air Force)

There are four lasers on the heavily modified 747-400 freighter, but only the COIL operates with liquid and gaseous chemicals. The others are lower-powered lasers used to identify, define and track boosting missiles.

ABL is a boost-phase segment of the Missile Defense Agency's (MDA) layered system of missile defense. Other elements include a mid-course defense and a terminal-phase defense.

ABL’s exclusive job is to station itself near a zone from which missiles are likely to be fired, then to find, track and destroy the weapons soon after they leave their launchers. ABL uses infrared sensors and two of its four lasers to identify a newly launched missile and determine its suitability as a target. A third laser measures and compensates for the atmospheric disturbance between the aircraft and the target. The fourth and final laser to fire -- the COIL -- causes the missile to kill itself when the powerful beam heats up the metal skin over the missile’s fuel tank, causing it to rupture.

YAL-1A is currently in a hangar at Edwards while preparations are being made to install the COIL and the complicated optical system that guides the laser beams to the target.

The COIL beam-generating process begins when chlorine gas is injected into a spray of hydrogen peroxide and chemical salts, producing excited oxygen. Iodine gas is then mixed with the excited oxygen to produce excited iodine. When the iodine returns to it normal or ground state it emits flashes of light called photons, which are collected and amplified to create a beam capable of zeroing in on a target several hundred miles away.

Although one laser module has been successfully built and tested, manufacturing 118 per cent of anticipated power, no one has ever successfully fired a unit comprised of the six modules to be used on YAL-1A -- each the size of an SUV turned on end and weighing 4500 pounds.

The six-module unit is being assembled in a special hangar in the ABL area at Edwards called the system integration laboratory. The modules will be tested there before they are installed on YAL-1A, which is in its own protected area nearby.

"If things go according to plan, we will be firing the six modules by next spring," Col. Pawlikowksi said.

She said after the batch was mixed and evaluated it was ejected and neutralized in a test of the system ABL proposes to use to dispose of its volatile chemicals in case of an in-air emergency.

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