WASHINGTON -- One of the most arresting television images shown around the world yesterday was that of laser-guided bombs flying through the "front door" of an Iraqi building as the U.S. F-111 launching aircraft veered to the right and headed home. The building was blown apart.
The "smart" bomb used was the ultimate in sophisticated weaponry -- combining television, infrared imaging, microprocessing and laser-lighting of a target.
This was indeed a "surgical" air strike of the kind long talked about by airmen but seldom achieved until the recent development of guided weapons that can be sent unerringly to their intended destinations.
As with kindred land and naval weapons, the object is "one weapon, one kill" -- although two were used for insurance on this occasion.
The weapons used against the Iraqi bunker yesterday were probably GBU-24s (guided bomb units), known to aircraft crews as Paveway III, said Maj. Dick Cole, an Air Force expert.
Videotape run for reporters in Saudi Arabia also showed, even more dramatically, how a radar-evading F-117 fighter put a "smart" bomb down the air shaft of Iraqi Air Force Headquarters and blew it apart.
Major Cole said weapons used by the Stealth fighters could not be discussed. But they presumably functioned in about the same way as the Paveway bombs flown into the fortified bunker's door.
The laser-guided bombs (LGBs) are "super-improved" versions of weapons introduced late in the Vietnam War, according to Major Cole. The Paveway has been in service since 1987.
These LGBs are ruggedly designed, intended originally for operation from British-based F-111 fighter-bombers in foul weather over Europe if war broke out with the Soviet Union.
Those F-111s are now in the gulf war. Each plane can carry four LGBs, costing from $11,000 to $100,000 each, depending on the mission and degree of sophistication required, the Air Force officer said.
A rotating pod is mounted under the center line of the aircraft. Inside are a television-like camera and a laser designator -- a sort of powerful flashlight.
As the pilot handles the airplane, his weapons systems officer (WSO)manually steers the camera and "flashlight." When a target appears in cross hairs on a screen before the WSO, he presses a button. A computer recognizes the target and turns the laser light on it.
Then the computer tells the LGB's warhead to wake up and look for the laser, which is concentrated light -- in yesterday's case, a small light on the building's front door. The computer, using speed, compass heading and other data, can release the LGB automatically.
With separation of the missile from the aircraft, the pilot can veer away -- 2 to 3 miles from the target -- and head for safety. The pod beneath the plane rotates, keeping the laser light focused on the target as long as need be.
The missile's warhead -- more accurately, "seeker" head -- carries a laser light seeker, a microprocessor and automatic pilot so that it can make course corrections as it bears down on the target.
There is, Major Cole said, nothing special about the actual explosive delivered by this sophisticated combination of crew, aircraft and technology.
Inside the missile there was, yesterday, a standard 2,000-pound bomb.
Several Maryland military facilities, including the Johns Hopkins Applied Physics Laboratory near Columbia and Martin Marietta Corp.'s laboratory in Relay, have been involved in the development of the new smart bombs.
The smart bombs may soon be giving way to ever smarter weapon systems.
Martin Marietta and Texas Instruments are working on an $80 million contract to develop the Advanced Anti-Tank Weapon System-Medium (AAWS-M) that is even more sophisticated.
The AAWS-M uses infrared imaging to guide a tank-killing missile to its target.
In simple terms, it works like this: The soldier uses a scanner that produces a television picture of the battlefield. When the intended target comes into view, the user activates infrared sensors that read the heat of the target, compared to other objects in the picture, and relays that information to a computer in the missile portion of the weapon system.
When the missile is fired, it follows the heat signature of the target, even if the target is moving.