Survival in combat zones requires 'layers' of protection.

An armored combat vehicle two-thirds lighter than an Abrams tank but just as durable is viewed by many as a pipe dream. But Army scientists believe they are inching closer to that goal, even though they recognize that it may take many years and considerable investment to make it a reality.

Army laboratories have for decades been pushing the limits of combat survivability technology, but the pressure to produce results rose when the service launched the Future Combat Systems in 1999, a program to develop a family of high-tech vehicles by 2012.

During the past two years, however, the Army realized it could not wait that long to field improved hardware to protect vehicles, particularly "soft-skinned" trucks. The service needed to respond immediately to the situation troops face in Iraq, where U.S. combat vehicles and supply convoys routinely take hits from roadside bombs, mines and rocket-propelled grenades.

The Army has shipped hundreds of armor kits to harden trucks, but that only is a temporary fix and not the ideal solution, officials said, because armor adds thousands of pounds of weight to vehicles, which causes engine failures and uses up valuable payload.

Searching for alternatives to old-fashioned steel armor is a team of scientists at the Tank-Automotive Research, Development and Engineering Center, or TARDEC.

Although they were asked to focus specifically on the Future Combat Systems, TARDEC researchers said some technologies could be fielded in the near term.

No substitute for steel armor has yet been found that can do the job without breaking the bank, according to Army engineers. TARDEC's approach is to develop a "suite" of technologies that can be mixed and matched, depending on the vehicle.

"Our intent is to provide the same protection in an 18-ton vehicle that soldiers would get from a 70-ton tank," said Steve Schehr, associate director for survivability technologies at TARDEC.

The only way to accomplish that, he explained, is to apply "layers of technology," ranging from lightweight ceramic armor to active defenses, electronic countermeasures and stealth coatings.

Armor has been the primary mechanism for protecting vehicles, but when weight becomes an issue, the preferred materials are ceramic composites, which are far more expensive than steel.

While military-grade steel is about $1 dollar a pound, aluminum is about $2 per pound. Titanium is $7 to $8 a pound. Kevlar is at least $25 per pound and higher for more exotic variants.

Active defense--a hard kill of an incoming threat--is a budding technology that shows much promise, Schehr told National Defense. Electronic-warfare countermeasures can defeat incoming munitions with radio waves.

Stealth coatings can help make a vehicle less detectable, particularly at night. Advanced materials now being tested would make it almost impossible for enemies to see a truck at night, even with night-vision infrared goggles. "Coating, shapes, materials ... all can reduce signatures," Schehr said. "You can pick and choose the technologies for a particular vehicle."

Active protection is a "prime candidate" for FCS, he said. "We are looking at putting a system on Stryker," the Army's newest light armored vehicle.

Chuck Acir, also with TARDEC, said the active protection works best against chemical-energy projectiles, which carry high-explosive charges.

Active defense against kinetic-energy weapons won't be fielded until much later because the technology is more complex, Acir noted. Kinetic-energy projectiles use high velocity and mass to penetrate a target.

None of these active-protection systems, however, is effective against mines or roadside bombs.

Although many Army officials favor the deployment of active protection on combat vehicles or trucks, it is a technology that many commanders view skeptically, because they fear it will lead to fratricide.

The employment of active protection requires specific tactics and training to be effective, said Acir. "Each active defense system may have different tactics, techniques and procedures associated with it ... The Army is wrestling with that a little bit."

Among the big unknowns in TARDEC's survivability program is whether the Army can find a way to lower the cost of manufacturing ceramic armor.

The best, but also the most expensive, material for light armor is silicon carbide ceramic, said Steve C. Taulbee, an armor expert at the Army Research Laboratory.

TARDEC is funding a manufacturing technology program, called Mantech, to help contractors develop ceramic armor less expensively.

The payoffs could be huge, said Gregory Wolfe, also an armor expert at ARL. "You could see 20-30 percent less weight by using ceramic materials." Drawbacks also must be taken into account. The lighter the armor, the thicker the panels can get, which compromises space efficiency, he added. Another potential pitfall in ceramic armor is that it can easily crack, depending on the size of the tiles.

Industry experts assert that the performance of ceramic armor on light-skinned vehicles (trucks and armored personnel carriers) continues to evolve at a rapid pace.

Silicon carbide is just one of several ceramic materials that can be used in lieu of steel, noted Marc A. King, vice president of Ceradyne Vehicle Armor Systems. "Silicon carbide has emerged as one of the preferred solutions for this application."

The cost of silicon carbide, and for all armor for that matter, generally is driven by market demand and by customer requirements, he explained. Just 24 months ago, the Army had no plans to up-armor trucks and did not foresee such a requirement. Today, armor is a mandatory feature for any new military truck. The value of the equipment being protected traditionally has factored into decisions on how much to spend on armor. For so-called "high value" assets such as helicopters, ceramics have long been the armor of choice for survivability applications, King said.

But the Iraq conflict reversed the conventional wisdom, as logistics forces are as exposed to attacks as front-line fighters were in the past.

Increasing demands for silicon carbide have led companies to ramp up their manufacturing capacity, which could help lower the cost, said King. Other market forces, such as rising prices for armored steel, he added, have worked to close the gap in the cost differential between steel and ceramic products.

The sudden rise of the U.S. government's demand for armored steel has had significant impact on the supply chain, King said. "The government gets first shot at the steel that is available," but it may still encounter problems obtaining enough steel because only a limited number of mills have been qualified as Defense Department suppliers. "There is enormous pressure on the mills to produce at max capacity, but they can't keep up with the demand," King wrote in an email. Further, these mills may be reluctant to expand capacity, given the uncertainty of the military market. "What do you do with the excess capacity if the situation changes and the demand suddenly drops?" King asked.

Other considerations--such as the preparation, manufacturing and handling of armored steel--increase the cost of the finished item, "but these costs have not been considered in the past," King said. The price tag for raw materials should not be the only measure, he contended. Rather, it should be the "overall lifecycle cost that needs to be the final determining factor in the decision making process."

Just as the price of silicon carbide is declining, so is the cost for other armoring materials like boron carbide and aluminum oxide, according to King. "The old perceptions regarding ceramic armor simply do not apply any longer."

He said the Mantech program can be a useful for companies that don't have corporate funds to pay for research and development, but when given the choice, suppliers often prefer to invest their own R&D dollars on product improvements, to ensure that they can retain the intellectual property.

Some defense firms, meanwhile, are pursuing independent projects focused on vehicle protection, hoping to draw the attention of Army decision makers. One of TARDEC's contractors, United Defense LP, has installed a number of prototype survivability devices on a Bradley armored infantry vehicle.

At the recent Association of the U.S. Army convention in Washington, D.C., the company displayed a Bradley outfitted with several systems, including an active protection device that defeats RPGs from close range, said UDLP spokesman Herb Muktarian.

The company also has been testing electromagnetic armor, which uses electricity to disperse an incoming charge. The problem with EM armor, however, is that it requires lots of energy, making it an ideal system for electrically powered hybrid vehicles.

Meanwhile, UDLP is funding the development of "transparent armor," a proprietary technology that produces clear armored panels that would shield the commander's hatch.