Because these missiles vary in their schemes for rejecting decoys, researchers are trying to develop a one-size-fits-all flare pattern. They are running thousands of computer simulations to examine as many flare pattern combinations as possible. Then they test the best ones in the field.

This past summer, the researchers tested decoy flare patterns on military aircraft at Eglin Air Force Base in Florida as part of their project for the U.S. Air Mobility Command and the Air National Guard. Field tests are key to tailoring the flare pattern to individual aircrafts and determining the relative success rate between different patterns, researchers explain.

In these tests, researchers use real flares and real planes, but captive missiles in seeker test vans, which behave as though the missiles were in flight. If the missile seeker transfers its track from the aircraft to the decoy, then the flare pattern is considered a success.

At Eglin, GTRI researchers evaluated flares on four large transport aircraft: the C-5, C-17, C-130 and MH53. This followed a field test in May 2003 in Yuma, Ariz., which evaluated new flares for the A-10, F-15 and F-16 fighter planes.

Although GTRI has been developing countermeasures for many years, the war on terrorism has accelerated efforts.

"We're working at a heavy, steady pace - building on the progress we make from each test," says project director Charles Carstensen, a senior research scientist in GTRI's Electro-Optics, Environment and Materials Laboratory. "Flares are part of our country's overall requirement to be prepared to fight. If we're ready to fight, then there's less likelihood we'll need to."

Made of magnesium, decoy flares confuse a missile's tracking system by burning white-hot when dispensed. They can defend military aircraft against man-portable air defense missile systems (MANPADS), which use infrared sensors to detect jet engine exhaust.