Engineers mix batch of laser chemicals

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A 1,200-gallon batch of chemicals that help make a laser beam capable of destroying a ballistic missile was recently prepared and assessed by airborne laser engineers from here.

The event occurred at the Edwards Air Force Base, Calif., ABL facility shortly after a shipment of 4,400 gallons of hydrogen peroxide was delivered to the laser’s chemical mixing facility, said Col. Ellen Pawlikowski, Kirtland-based ABL program director.

"We're very excited about this batch because it's the initial step taking us to first light," said Colonel Pawlikowski, referring to producing a laser beam from the chemical oxygen iodine laser modules that will be installed on ABL's first aircraft, YAL-1A.

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, a killer laser, Colonel Pawlikowksi said.

There are four lasers on the heavily modified 747-400 freighter, but only the COIL operates with liquid and gaseous chemicals, said Colonel Pawlikowski, who holds a doctorate in chemical engineering from the University of California at Berkeley. 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 layered system of missile defense. Other elements include a midcourse defense and a terminal-phase defense.

Its job is to station itself near a zone where missiles are likely to be fired from, then find, track and destroy the weapons soon after they leave their launchers.

System officials said it 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, Colonel Pawlikowksi said. When the iodine returns in a 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 percent of anticipated power, Colonel Pawlikowksi said no one has ever successfully fired a unit comprised of the six modules to be used on YAL-1A. Each of this is the size of a sport utility vehicle turned on end and weighing 4,500 pounds.

The six-module unit is being assembled at the system integration laboratory, a special hangar in the ABL area at Edwards AFB. 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," Colonel Pawlikowksi said.

She said after the batch was mixed and evaluated it was ejected and neutralized to test the system ABL proposes to use to dispose of its volatile chemicals in case of an in-air emergency. (Courtesy of Air Force Materiel Command News Service)