In the early years of the Iraq war, the U.S. military developed a technology so secret that soldiers would refuse to acknowledge its existence, and reporters mentioning the gear were promptly escorted out of the country. That equipment – a radio-frequency jammer – was upgraded several times, and eventually robbed the Iraq insurgency of its most potent weapon, the remote-controlled bomb. But the dark veil surrounding the jammers remained largely intact, even after the Pentagon bought more than 50,000 units at a cost of over $17 billion.
Recently, however, I received an unusual offer from ITT, the defense contractor which made the vast majority of those 50,000 jammers. Company executives were ready to discuss the jammer – its evolution, and its capabilities. They were finally able to retell the largely-hidden battles for the electromagnetic spectrum that raged, invisibly, as the insurgencies carried on. They were prepared to bring me into the R&D facility where company technicians were developing the what could amount to the ultimate weapon of this electromagnetic war: a tool that offers the promise of not only jamming bombs, but finding them, interrupting GPS signals, eavesdropping on enemy communications, and disrupting drones, too. The first of the these machines begins field-testing next month.
On a fist-clenchingly cold winter morning, I took a train across the Hudson River to the secret jammer lab.
Tucked behind a Target and an Olive Garden knock-off, the flat, anonymous office building gives no hint of what’s inside. Nor do the blank, fluorescent-lit halls. But open a door off of one of those halls, and people start screaming.
“Screens off!” barks a man with a fullback’s build. “Turn off the test equipment!” On the ceiling, a yellow alarm light flashes and spins — the sign that someone without a security clearance is in a classified facility.
Afghan militants began attacking U.S. troops with improvised explosive devices in the first days after the October 2001 invasion. By early ‘02, al-Qaida bomb-makers were cramming radio frequency receivers and simple digital signal decoders into the bases of Japan InstaLite fluorescent lamps. Then they’d connect the two-and-a-half inch wide lamp bases to firing circuits, and to Soviet-era munitions. The result was a crude, radio-controlled weapon dubbed the “Spider” by the Americans. With it, an attacker could wait for his prey, set off the bomb at just the right moment — and never have to worry about getting caught. When the explosion happened, he’d be hundreds of yards away.
Worse, U.S. forces had no way of blocking the Spider’s triggering signal. Military bomb squads carried around a few half-assed jammers. But they couldn’t be mounted on vehicles, “and they were too weak to provide protection beyond a few yards,” Rick Atkinson notes in his exquisite history, Left of Boom: The Struggle to Defeat Roadside Bombs.
Navy engineers hustled to build something a little stronger, and a little more portable. By November of 2002, they had a jammer called Acorn that was hard-wired to stop Spiders. It wasn’t much. As a so-called “active jammer,” the Acorn put out a relatively-indiscriminate “barrage signal” that ate up power and generated all kinds of interference. That kept its effective radiated power — the amount of signal hitting any one bomb receiver — low. The signal was so weak, the jammer had to be left on and screaming constantly. Otherwise, troops would be inside the bomb’s danger radius before they ever had a chance to block it. Worse, it could only block the specific receivers used in Spiders. If the bombers switched frequencies, the countermeasure would be useless.
Meanwhile, the Army looked for ways to modify its Shortstop Electronic Protection System, designed to shield troops from artillery and mortar fire. This was a so-called “reactive” countermeasure. It monitored the airwaves, listening for one of the radio signals used by the munitions’ proximity fuses. Once the countermeasure heard that signal, Shortstop recorded it, modified it, and then blasted it back at the munition. By confusing the weapons with their own signals, Shortstop could fool the shells into prematurely detonating.
The soldiers tweaked the Shortstop to scan for radio-controlled bombs’ triggering frequencies, and to rely on a Humvee’s power supply. “The wife of one Fort Monmouth engineer collected miniature kitchen witches that inspired a new name for the device: Warlock Green,” Atkinson recounts.
Five Warlock Greens accompanied U.S. forces into Iraq in March, 2003. By mid-summer, there were 100 jammers in the warzone. It wasn’t nearly enough. Iraq’s militants had learned from their compatriots in Afghanistan, and were setting off remotely-detonated explosives everywhere.
Just like the first turn of this improvised explosive device (IED) war, the electronic countermeasures were having trouble keeping up with the bombs. It took Warlock Green, ultimately manufactured by the EDO Corporation, a couple of seconds to record, modify, and rebroadcast a triggering signal. An insurgent bomber could set off an explosive in a few fractions of a second, if he had a simple, low-powered trigger, like a garage door opener. The jammer didn’t have time to catch up.
The jammers could only cover a small slice of the radio frequency spectrum. Whenever the insurgents should change triggers — from say, door openers to key fobs — the jammer-makers would have to go back to the drawing board. Warlock Greens could be reprogrammed, within limits. The Acorns couldn’t; the new threats rendered them useless.
“Every time we put a countermeasure in the field – especially with Warlock – they were able to outstrip it,” says Paul Mueller, a long-time defense executive, who supervised jammer-building operations at EDO and at the ITT Corporation. “They were a step ahead of us.”
‘Every time we used a countermeasure, they were able to outstrip it.’
But with insurgents setting off 50 IEDs a week, even the step-behind jammers were better than no jammers at all. By May 1, 2004 — one year to the day since President George W. Bush declared the end of major combat operations — the improvised bombs had wounded more than 2,000 American troops in Iraq. The IEDs killed 57 servicemembers in April alone, and injured another 691. “IEDs are my number-one threat in Iraq. I want a full-court press on IEDs,” Gen. John Abizaid, then the top military commander in the Middle East, wrote in a June 2004 memo.
In the early fall of 2004, the Army signed a contract for 1,000 Warlocks. By March, 2005, the Army upped that order to 8,000 jammers. It was a high-tech, electromagnetic surge. And it was meant to send the militants sliding back down the scale of sophistication. “If somebody can sit a click [kilometer] away with a radio and target our guys, we’ve got almost no ability to get him,” says a source familiar with the jammer buildup. “But if he’s doing the Wile E. Coyote thing, and pushing down that plunger, at least we’ve got some chance to shoot him before he gets it down.”
All the big defense contractors — and lots of little ones — got into the electronic countermeasure business. The Marines bought one model; the Army another; Special Operations Forces, a third. The Army began buying Warlock Reds — small, active jammers that blocked out the low-powered triggers that Warlock Green couldn’t stop in time. Warlock Blue was a wearable jammer, to protect the infantryman on patrol. Each countermeasure had its shortcomings; Warlock Blue, for instance, was “a half-watt jammer at a time when some engineers suspected that 50 watts might be too weak,” Atkinson notes. But no commander could afford to wait for a perfect, common bomb-stopper; too many men were getting blown up. By May 1, 2005, the number of U.S. troops wounded by the bombs had climbed to more than 7,700.
There were drawbacks to throwing all those countermeasures into the field at once. Warlock Green would sometimes mistake Warlock Red’s signal for an enemy’s, and go after it. That would lock the jammers in a so-called “deadly embrace,” cancelling one another out. (end of excerpt)
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