Controlling Iraq's crowded airspace no easy task.

An untidy web of unmanned drones and helicopters hovering over combat zones in Iraq has created dangerous flying conditions, prompting the Army to create a specialized cadre of air-traffic controllers whose job is to prevent collisions between friendly aircraft.

"As we proliferate more

The Army, Air Force, Navy and Marine Corps operate than 1,000 UAVs and countless helicopters in Iraq. Most fly at low altitudes, below 3,000 feet, noted Lt. Gen. Walter Buchanan, commander of the 9th Air Force and Central Command Air Forces. "That is a very thick environment," he told reporters. "We in fact have had occasions where they have run into a helicopter. Thankfully, to my knowledge, we have not hurt anybody yet."

The Air Force traditionally has the airspace management expertise, but the job mostly involved aircraft flying above 10,000 to 15,000 feet. The Army decided it needed to develop its own skills because its aircraft typically fly at much lower altitudes than Air Force jets, and often need to interact with troops engaged in combat. "You might have missiles flying, UAVs, communications relay systems, intelligence systems, all in the same airspace, staring at the same area on the ground," says Brig. Gen. Robert P. Lennox, commander of the U.S. Army Air Defense Artillery Center.

To coordinate the traffic of low-altitude aircraft, Army is fielding six-person units, which are assigned to brigade command posts across Iraq. Their job is to "synchronize the airspace," Lennox tells National Defense.

Controlling the use of the airspace can be difficult particularly in congested areas where U.S. troops may be searching for insurgents or weapons caches. "Everyone wants to look at the same piece of ground," Lennox says. "We are arming our commanders with hundreds of UAVs," he says. "How do they know how to manage the airspace, tell friendly from enemy UAVs?"

The Air Defense Artillery Center has begun deploying "airspace management cells," made up of both aviators and air-defense specialists, Lennox says. "They are designed to go into our maneuver brigades and provide them situational awareness of what's going on overhead."

The cell also coordinates air-traffic data with Air Force operators aboard AWACS radar planes. The primary source of information on what aviation assets are flying in the area is the Army's tactical airspace integration system, or TAIS.

Operations in a crowded airspace create a propitious environment for friendly fire incidents, Lennox says. "We have to practice, exercise, to make us better and not to cause fratricide."

Buchanan said the hazards are compounded by an abundance of electronic radio signals in Iraq--attributed both to the heavy use of radio communications and of electronic jammers that are employed to disable remote-control bombs. Such a crowded spectrum creates conditions for "electronic fratricide," which potentially could result in troops jamming friendly radios, Buchanan noted.

The growing emphasis on UAV operations and airspace management is part and parcel of a broader shift in the missions of the Army's Air Defense Artillery Center, Lennox explains.

"Our mission of shooting down enemy aircraft is not as relevant anymore," he says.

As part of a major restructuring of Army units that started more than three years ago, short-range air-defense units were drastically downsized and merged with Patriot ballistic-missile defense units. The combined organizations are known as "air-and-missile defense battalions," says Lennox.

One probable growth industry for Lennox's organization is cruise-missile defense. The Defense Department increasingly is becoming concerned about the proliferation of guided missiles that could be launched from a ship or aircraft, functioning like self-contained precision bombs. These cruise missiles are relatively easy to build and target, according to Pentagon studies.

One of the primary weapons that will provide defenses against cruise missiles are the surfaced-launched advanced medium range air-to-air missile. The SLAMRAAM, which is mounted on Humvee trucks, will enter service in 2009, Lennox says. Another cruise-missile defense asset is an aerostat equipped with sensors, known as JLENS, or joint land-attack cruise missile defense elevated netted sensor system. It provides over-the-horizon surveillance from altitudes between 10,000 and 15,000 feet.

Ballistic and cruise missiles, by and large, have not threatened U.S. troops in Iraq, where insurgents have made rockets, artillery and mortar rounds their weapons of choice, besides roadside bombs.

While improvised explosive devices are the number-one killer of American soldiers and Marines in Iraq, artillery and mortar attacks rank second, says Lennox. The Army Artillery and Air Defense Center has been pursuing classified programs dubbed CRAM, for counter rockets, artillery and mortars.

"We've been developing and testing capabilities to knock these down in flight, warn friendly forces [of an incoming attack] and get the bad guys," Lennox says.

Directed-energy weapons offer promising solutions to the CRAM problem, he adds. Once the Army begins to field laser weapons, for example, soldiers' ingenuity will result in numerous applications for these technologies. "You'd be amazed once you get it in the hands of soldiers, what they can do with it," Lennox says. Troops will employ lasers to "blind" UAVs and to defeat rockets, artillery and mortars. "We have laser-based systems that detonate unexploded ordnance and mines. The sky is the limit if you can develop a deployable system that has enough energy and power."

Northrop Grumman Corporation recently received a $38 million contract for CRAM systems integration. The company will deploy a mortar-attack warning system and install the technology at eight military bases in Iraq. CRAM uses radar sensors to detect and track fired rounds. Once a threat is detected, audio and visual alarms sound to warn exposed soldiers. A fire-control subsystem predicts the mortar's flight path, prioritizes targets, activates the warning system and provides cueing data to defeat the mortar round while it is still in the air.