Dark World of Aircraft Countermeasure Technology

The Civil War-era mill town of Nashua, N.H., is not, at first glance, the likely location of a clandestine struggle for the future of military air superiority. The city usually only gets national media attention during political primaries, with candidates stumping over pancakes at the reputedly haunted local restaurant. But since 1951, Nashua has been at the forefront of a struggle that has outlived decades of wars, including the Cold War. Tucked into the basement of a nondescript Civil War-era building is BAE Systems’s Jam Lab, where designers figure out ways to thwart anti-aircraft missiles that target military and civilian airplanes.

Although the Jam Lab staff is polite and eager to answer most questions, it’s hard for an outsider to feel welcome. Overhead banks of yellow warning lights twirl while visitors are in the facility; the blunt system warns staff to watch what they say and do. No one without security clearance can even set foot in the break room. This secrecy and access control is needed to serve military clients, but in this case it’s more than “loose lips sink ships” paranoia. There are opposing forces–chiefly Russian anti-aircraft designers, some of the world’s best–who would like to get a peek at what the Jam Lab is doing to the anti-aircraft missiles the Russians make and sell.

Anti-aircraft missiles use infrared signatures and other tracking sensors to identify and destroy warplanes. They come in a frightening variety of forms, from advanced vehicles equipped with radar that can track multiple targets to shoulder-fired systems that are so easy to operate that teenagers can be trained to shoot them effectively. The missiles use seekers in their tips to acquire targets–to evade them, a warplane must slip from the seekers field of vision and, ideally, leave a flare or bits of metal, or “chaff,” as a decoy for the missile to pursue.

BAE does not purchase AA systems from Russian or Chinese vendors. Instead, unspecified friends of the government (spook talk for the intelligence agencies of the U.S. and its allies) deliver missiles captured from the field. These captured missiles are subjected to a prolonged afterlife of relentless testing.

A captured missile’s first stop is a clean room, where its brain is wired to relay the commands that the guidance system sends to its steering fins. Strapped to testbeds, the Jam lab researchers first determine how the missile tracks its targets. Any new methods are revealed by this electronic vivisection. “We’re always looking for, and asking for, new threat systems,” says Paul Squires, the Jam Lab’s senior principal physicist.

After this initial assessment, a captive missile’s long “undeath” is just beginning. Over and over, the missile’s brain relives target acquisition and guides itself (sans warhead-equipped body) to a heroic, suicidal demise. Thousands of 10-minute simulations allow researchers to change variables and retest for years if need be. One missile’s brainstem has been trapped in this limbo, undergoing daily testing for more than seven years.

The captured missiles are also used as countermeasure guinea pigs. For example, tables equipped with mirrors guide laser beams that blind the infrared seekers on the tips of missiles. The lasers are invisible and powerful at close ranges–Squires says that unwary testers’s neckties sometimes get burned when they lean to close to the beams.

Many modern systems combine infrared (IR) with newer methods, like radiofrequency sensors and phased-array electronic radar beam steering. Advanced imaging systems that can tell the IR signatures of a flare from those of a warplane are in development: Squires calls these the “next wave” that he must prepare against. Older but lethal shoulder-fired systems, like the Russian built SA-7 and SA-18 have been getting their IR seekers upgraded with radiofrequency sensors.

The centerpiece of the Jam Lab, beyond its collection of deadly missile hardware, is a five-axis machine that can test the way the seekers react to harsh flight maneuvering. For example, a seeker can be mounted on the two-axis part, measuring its flight path. A jamming system can be mounted on the three-axis portion of the machine, and when the simulation runs, each reacts as if the life and death fight is under way.

The entire machine shudders and twists as the missile tries to acquire the target, and the jamming equipment is subjected to some of the forces an airplane endures when trying to avoid a missile. The data can be used to generate an animation of the movements of the missile and target. The rumbling rattles the basement offices and shakes the upper floors of the building.

The Other Side

For U.S. and NATO countermeasures researchers and for Russian anti-aircraft missile designers, the Cold War never ended. Between 1991 and 2000, all but four of the 17 total U.S. aircraft that had been shot down in combat were hit with missiles, according to a study by the Air Force Historical Research Agency. And in the case of each downed aircraft, the missile delivering the killing stroke was of Russian design. Shoulder-fired SA-7 missiles, vintage Russian innovations, have shot down several U.S. helicopters in Iraq.

Russia’s proficiency in anti-aircraft weapons dates to the closing days of World War II. German rocket technology was passed along to the Russians, who took its lessons to heart. They had seen what fleets of British and American bombers could do to a nation, and as the Cold War percolated, air defense systems became an increasing priority. By the 1990s, Russian anti-aircraft weapons had been sold across the world. Clients included Saddam Hussein; An updated SA-2 is credited with shooting down an F-15 in January 1991, the only enemy missile to ever destroy one.

When NATO moved against the Serbs in Bosnia, plenty of Russian weapons were aimed skyward. Scott O’Grady was shot down with an SA-6, a radar-guided missile with a big warhead. An SA- 3 shot down an F-117A stealth fighter, using means that are still fairly mysterious. According to Russian television, the crew was tipped off by a spy watching the runway in Italy, and timed the shot to match the stealth airplane’s location, using VHF radars to track the airplane. The Russians have since admitted to its domestic press, almost as a sales pitch, to picking through the wreckage and using the downed aircraft’s remains to test new anti-aircraft missiles.

These days, Russian anti-aircraft gear is heading to hot spots like Iran, Syria, Cuba and Venezuela. Russia sold many systems to China as well, but the orders dried up as China began reverse-engineering their own designs from Russian plans. These Chinese knockoffs present another problem for jam labs–each needs to be tested separately, because variations and improvements react to jamming in different ways.

Other players, like South Africa and Brazil and Sweden, are also entering the anti-aircraft market. Squires says one person at the Jam Lab reads all the international open-source literature to remain up-to-speed on any emerging threats and collects the updates in the classified library on the premises. “It’s a cycle,” he says. “It takes a couple years to obtain a new seeker and develop a countermeasure. Then it’s another couple years before its fielded, and then they can respond. But that takes another five years of development.”

The Future

The miniaturization of electronics and sensors is increasing the threats that missiles pose. With fewer (but more advanced) warplanes being built, the need to protect aircraft is enormous.

Next-generation protection is being developed in jam labs across the nation. High-power microwave (HPM) emitters can bathe incoming missiles in a broad frequency band. On the ground, where weight is not an issue, large HPM devices could be used to detonate inbound missile or mortar warheads, but in the sky the smaller systems can scramble missiles without the need to focus the beam, as with lasers. Older, more reliable systems have new purposes. New flares and chaff are being continually upgraded to better mimic the flight of airplanes and work in conjunction with other jamming systems to foil missiles. Old airplanes like converted B-52 heavy bombers are being reborn as jamming platforms, and UAVs are natural platforms for this form of electronic warfare .

The decades-long cat-and-mouse struggle is far from over, and so the Jam Lab, hidden in its humdrum office park, remains in business. After we guests leave, the yellow warning lights will extinguish and the testing will continue. Just don’t ask what’s shaking in the basement, behind closed doors.

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