Released: Nov 10, 1997
This approval for the Airborne Laser program is part of an overall process to ensure the program is technically and financially sound before the Air Force can continue to use its resources.
At one of the two technical checkpoints, program officials had to prove they could track a theater ballistic missile in flight. This was done earlier this year in tests at the U.S. Army's White Sands Missile Range, N.M., conducted by scientists from the Air Force Phillips Laboratory here. Program officials showed they could detect and track a missile, then put and hold a laser beam on that missile.
This would be the warbird's role in combat: using sensors, computers and lasers to find, track and destroy attacking theater ballistic missiles, such as the Scuds that were used in the Gulf War. By destroying these missiles early in their flights, missile warheads and debris could fall back on the countries that launched the missiles.
The second technical checkpoint required program officials to show they could use a laser to track a missile while compensating for the effects that the atmosphere could have on that laser beam. Conditions in the atmosphere tend to distort a beam of laser light, weakening its effects on a target missile. But a series of experiments, conducted by the Massachusetts Institute of Technology's Lincoln Laboratory at Hanscom Air Force Base, Mass., proved that computers and deformable optics -- mirrors that can change their shape -- can neutralize the atmosphere's effects while tracking a missile.
Three lasers were used in the tests to simulate a high-energy laser being fired under strong, medium and weak atmospheric turbulence. In the tests, deformable mirrors were used with a laser in illuminating a target missile. Test officials verified that the laser met all design expectations.
Early in the program, Airborne Laser officials had acknowledged that correcting for the effects of the atmosphere on a laser beam would be a critical aspect in the success of the weapon. A recent Government Accounting Office report also identified the importance of atmospheric effects. But, the report was completed before the results of these and other on-going tests were included.
Over the past seven months, the Air Force has been conducting additional experiments worldwide using aircraft and instrumented balloons to gather atmospheric turbulence data. Scientists are collecting a database that includes seasonal changes, day-night differences and a variety of weather conditions. Data collected thus far further confirms that the Airborne Laser will be able to compensate for atmospheric turbulence and function as designed.
The results of these atmospheric turbulence studies confirm that the Airborne Laser design will destroy theater ballistic missiles.
Another future technical checkpoint will involve the laser. Program officials will have to demonstrate they can produce a chemical oxygen-iodine laser capable of generating the powers needed. The laser will also have to be within the weight parameters prescribed in the Airborne Laser design.