By Vernon Loeb
Washington Post Staff Writer
Tuesday, March 26, 2002; Page A16

Within weeks of the attacks on New York and the Pentagon last September, dozens of government scientists and engineers at the Defense Threat Reduction Agency in Fairfax County began working virtually around the clock to develop a powerful new bomb.

Their mission: come up with a device that could penetrate al Qaeda's cave complexes deep in the mountains of Afghanistan and kill the people inside.

By mid-December, the scientists were ready to go. In the Nevada desert, 65 miles north of Las Vegas, they detonated the world's first "thermobaric" bomb, which creates massive amounts of shock wave pressure from its blast.

Ten were quickly dispatched to U.S. forces in Central Asia, and three weeks ago the first one was fired by an F-15E at a tunnel in eastern Afghanistan at the start of Operation Anaconda, the offensive against suspected al Qaeda and Taliban holdouts.

The crash development of the weapon is just one example of how the war on terrorism is proving to be a potent laboratory for military innovation. Thirty new technologies, from armed aerial drones to dosimeters that measure exposure to toxic chemicals, have been rushed into use at home and abroad, the offspring of a $688 million effort over the past eight years to stimulate innovation at the Pentagon.

Among the devices being hurried into the development pipeline are foliage-penetrating radar sensors, micro-drones and microwave antipersonnel guns that stun, rather than maim or kill, officials say.

The results of the scientists' work likely will reverberate far beyond the campaign against terrorism. As the German blitzkrieg tactic of sudden, swift land attacks or the American Manhattan project that developed the first atomic bomb during World War II demonstrated, major wars lead to military innovations that revolutionize how conflicts are fought.

"Many of the weapons that remain the centerpiece of our military posture trace their origins directly to previous conflicts: the tank in World War I, radar on the eve of World War II, and of course the nuclear bomb, which defined an entire age," said Loren B. Thompson, a defense consultant at the Lexington Institute, a public policy research organization.

Eight days after the Sept. 11 attacks, Ronald M. Sega, who directs research and engineering at the Pentagon, called a dozen defense technology officials together to talk about what projects should be accelerated to support the impending war.

Sega said three emerged from a crowded field of 150 projects: the thermobaric bomb, a bunker-busting, air-launched cruise missile, and a "nuclear quadrapole reasonance" sensor to detect the presence of bulk explosive materials in trucks and shipping containers.

He said all three have been deployed, either in Afghanistan or the United States.

The thermobaric bomb resulted from a problem bedeviling Pentagon planners. Many al Qaeda fighters were burrowed deep inside vast cave complexes in Afghanistan's mountains. Short of a ground invasion to roust them cave by cave -- a proposition that would likely lead to a large loss of American lives -- getting at the terrorists was problematic.

"We looked at thermobarics and said, 'Hey, we could do this really quickly and provide a significantly improved capability,' " said Stephen M. Younger, director of the Defense Threat Reduction Agency.

The thermobaric bomb releases and then detonates a fine cloud of high-explosive chemicals, creating devastating shock waves that destroy everything -- and everyone -- inside a cave, bunker or building. The term thermobaric is derived from the effects of temperature -- the Greek word for heat is "therme" -- and air pressure -- the Greek word for pressure is "baros" -- on the target.

Only one has been dropped in Afghanistan on what Gen. Richard B. Myers, the chairman of the Joint Chiefs of Staff, called a "tactically significant" cave. Although the device detonated as envisioned, a problem with the laser-guidance system caused it to fall short of the cave entrance, negating its effectiveness, a defense official said.

In addition to the thermobaric bomb, the Afghan war will be remembered for its tactical advances -- the fusion of Special Operations Forces spotting targets on the ground and long-range bombers firing at them from the air, for example. It also has marked the first use of armed unmanned drones, with the CIA using surveillance Predators to launch Hellfire antitank missiles, and the first operational flight of the Global Hawk, an unmanned surveillance plane that flies higher and longer than the Predator.

Air Force officers working out of a special operational cell at the Pentagon called Checkmate figured out how to feed surveillance video from a Predator directly into an AC-130 gunship's computers for real-time targeting.

Navy pilots flying EA-6B Prowlers off aircraft carriers found themselves playing a new role in jamming enemy ground communications. Army Special Forces troops devised new ways of communicating target coordinates to incoming fighter and bomber pilots.

There can be dangerous and costly consequences to such experimentation, however.

One $30 million Global Hawk crashed in late December after a mission over Afghanistan. And two friendly fire incidents that left three U.S. soldiers dead and more than two dozen wounded apparently took place after target coordinates were miscommunicated from U.S. ground forces to pilots firing satellite-guided bombs.

But even with such setbacks, defense officials and analysts say the pace and scope of innovation in wartime -- and the immediate feedback on how the new weapons are performing on the battlefield -- are invaluable. In this respect, they say Operation Enduring Freedom, as the Pentagon calls the Afghanistan war, is already proving its worth.

"The most important innovation of Operation Enduring Freedom was the netting together of forces that traditionally weren't regarded as having much to do with each other: strategic bombers and Special Forces, ground forces and Navy electronic aircraft," Thompson said.

Indeed, the war has been a near-perfect laboratory, according to Michael Vickers, a military analyst at the Center for Strategic and Budgetary Assessments, a defense think tank. Vickers, a former Army officer and CIA operative, said the success came because the al Qaeda network and the Taliban government sheltering it were overmatched opponents.

"When great powers fight smaller wars -- precursor wars in between the old military world and the new military world -- you can experiment more because there's no doubt you're going to win," he said. "You experiment, and there is real feedback. You don't get that very much in the military."

In Afghanistan, Vickers drew a distinction between technical innovation, such as development of the thermobaric bomb, and what he considers even more important organizational and tactical innovation, such as linking Special Forces on the ground with bombers in the air.

"This was a new way of war, a new operational concept," Vickers said. "And it was a pretty significant innovation, because we got fairly rapid regime change with it. This wasn't on the shelf. This was the way we planned to overthrow governments."

But even this tactical advance was highly dependent upon new military technology, largely information technology linking the ground and air forces.

According to one Air Force case study documenting the fusion between soldiers and bombers, one lethal attack took place last fall after a commander with the anti-Taliban Northern Alliance asked U.S. Special Forces troops to help him maneuver through a valley occupied by a large Taliban garrison and troop concentration.

Using satellite communications, the Army troops called the Air Force operations center in Saudi Arabia to request an aircraft. The operations center immediately told an "on-station" B-52 to contact the soldiers.

Using a device called a Viper -- a portable laser range finder, digital map display and Global Positioning System receiver -- the soldiers calculated the coordinates of the Taliban garrison and troops and radioed them to the B-52 crew.

"Less than 20 minutes after the Special Forces operator was contacted, the B-52 crew passed over the target area and dropped a series of munitions on the Taliban garrison and troop concentration," the case study said. "The airstrike resulted in heavy Taliban casualties, the destruction of numerous fighting positions and artillery pieces, and significant damage to a command bunker."

One senior Navy official told of how Special Forces called in a carrier-based Navy warplane on four al Qaeda fighters in a sports utility vehicle who stopped and took cover under a bridge as soon as they heard the approaching jet.

With the Special Forces troops shining a laser designator on the enemy, the official said, the Navy pilot was able to "bounce" a laser-guided bomb and kill the enemy without damaging the bridge.

"They didn't know where it [was] coming from," the official said. "A lot of it was technology per se that enabled us to just kick these guys every time they put their head up."