Tech researchers are contributing to a new anti-ballistic missile system
MEL BELCHER doesn't wear a uniform. He didn't attend boot camp, and he doesn't fly helicopters, drive tanks or go into battle.
But he and colleagues at the Georgia Tech Research Institute are making vital contributions to U.S. defense -- by evaluating and applying the latest technology to missile defense radar development.
Their target? Ballistic missiles.
Mel Belcher (left) and Tracy Wallace display solid state transmit/receive modules for THAAD radar.
"The Gulf War was the first confrontation in which U.S. forces were really worried about ballistic missiles -- the "Scuds" [SS-1 missiles] the Iraqis shot," says Belcher, a senior research engineer in the Sensors and Electromagnetic Applications Laboratory. "My job, and that of the people who work with me, is helping the U.S. develop a defensive system that would counter those kinds of long-range threats."
More than 20 countries have ballistic missiles, according to figures from Lockheed Martin Missiles & Space -- and some are equipped with nuclear weapons.
One U.S. strategy for countering ballistic missile threats is the Theater High Altitude Area Defense (THAAD) program. THAAD researchers and engineers have planned, assembled and now are testing the world's first endo-exoatmospheric system designed specifically to defend against ballistic missiles. The system will intercept threatening missiles at altitudes more than 60 miles above the earth and is expected to have ranges of hundreds of kilometers, according to reports in Aviation Week magazine. The U.S. Army THAAD Project Office is based in Huntsville, Ala., and Lockheed is the prime contractor.
In addition to being the first system of its kind, THAAD also includes the most complex solid state radar ever built -- it incorporates 25,000 solid state modules. The project should be initially operational by the year 2002.
Belcher and his GTRI colleagues are helping develop THAAD's state-of-the-art, X-based phased-array radar, which will spot and track targets, as well as perform target acquisition, target tracking, determine if a target is destroyed after interception, and identify and classify threats. The GTRI team includes 10 to 15 specialists in antenna, receiver, solid state and signal processing technologies. Assembled at GTRI over the last 11 to 12 years, the researchers look at contractors and designs, suggest improvements, and support testing, analysis and modeling of different parts of the radar system.
"There were a lot of areas where we were pushing the envelope on what technology could do to get the resolution, accuracy and sensitivity required for missile defense," Belcher says. "GTRI has been very active in identifying key devices and components, determining what the specifications were and testing prototypes."
The team's analysis was instrumental in incorporating features into the THAAD radar system that now are recognized as essential to missile defense missions. Members are involved in THAAD testing at White Sands Missile Range, N.M.
THAAD differs from the Patriot missile system, familiar to many because of its role in the Gulf War. The new system is based on "hit-to-kill" philosophy -- the defending missile rams into the attacking ballistic missile.
"Most air defense missiles don't try to hit their targets," Belcher says. "They try to explode near them and spray them with fragments. That usually works efficiently. But what we found during the Gulf War was that you could pelt the Scuds with fragments, and they'd still come down and explode."
THAAD also is designed to intercept targets at higher altitudes than the Patriot system used during the Gulf War, thus keeping debris away from population centers and military assets. The new system could defend theaters as large as small nations, rather than the single airfields the Patriot defends.
Belcher began his career working in intelligence, looking at the former Soviet Union's missile defense systems. Over time, he switched to developing U.S. missile defense systems.
"It is truly one of the most challenging systems engineering problems out there," he says of his field. "When you are defending against attacking ballistic missiles, the aggressors may develop countermeasures and do other things that will degrade our capability of countering them."
Belcher's role at Georgia Tech is to expand programs in missile defense. In addition to expanding U.S. Army programs, he also has involved GTRI in the U.S. Air Force's early warning radar work.
He and his colleagues not only work on research projects -- they frequently are called upon to apply their radar expertise in other settings. At the request of the Ground Based Radar Project Office, Belcher and principal research engineer Dr. Larry Corey traveled to Iraq in 1994 with two colleagues from Dynetics, Inc. to inspect a radar the United Nations discovered in that country.
"The radar had an interesting history that deserved investigation," Belcher explained. "We served on a U.N. inspection team that negotiated with the Iraqis, inspected the radar and ultimately specified how it should be destroyed.
"These are all folks who could certainly be doing other things," Belcher says of the GTRI team. "However, we are motivated. I think everyone working on the project is keenly aware of the ultimate aims, and wants to see U.S. forces protected."
Belcher and the missile defense radar development group want to increase the amount of work they do on projects similar to THAAD. They plan to expand their participation on short range missile defense systems, as well as on studies on the feasibility of defending the continental United States.
The group also is working to establish an international cooperative research program in adaptive digital beam-forming (ADBF) between the United States and the United Kingdom. ADBF allows engineers to adapt antenna patterns by steering the null portion of the pattern toward sources of interference and away from potential targets. That ability maximizes the gain, energy and sensitivity directed toward the target, and thus provides the radar user more information.
"Adaptive digital beam-forming is promising for two reasons: The world has gotten nastier -- electronic countermeasures jamming has become more sophisticated, targets are smaller, aggressors have gotten better at masking target returns -- but at the same time, digital electronics have gotten a lot cheaper," Belcher explains.
"Given the proliferation of missile technology to third-world countries, it is important that the U.S. field a viable missile defense system in the near future," Belcher noted. "GTRI is helping the Army bring to fruition the defense of its forces in the field from ballistic missile attack."
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