Northrop Grumman Corp. [NOC] is proposing a ground-based system to protect airliners from terrorist missiles fired near airports, the company announced.

While Northrop has designed an aircraft-based anti-missile system, some airlines have protested that installing the systems on the thousands of airliners flown each day would be expensive, at a time when the airlines are reeling financially from soaring jet-fuel costs.

Ground-based systems, or perimeter systems, could be installed by airport authorities. Such systems would provide protection for aircraft only near airports, not during their flights. But airlines say terrorists would be most likely to fire missiles at planes as they take off from airports, or approach for landings.

Northrop thus counters Raytheon Co. [RTN], which also offers a perimeter system.

The Northrop system is called Skyguard, and the company sees it as part of a layered airport defense against terrorists wielding man-portable air defense systems (MANPADS) missiles to destroy airliners filled with passengers.

Since terrorists on Sept. 11, 2001, boarded four airliners and commandeered them, flying two into the World Trade Center towers (demolished) and Pentagon (heavily damaged on one side), passenger screening security has been tightened substantially.

Thus terrorists are seen more likely to launch attacks in ways that don’t involve boarding planes as passengers, such as launching MANPADS as planes take off or land.

Northrop submitted its Skyguard proposal to a unit in the Department of Homeland Security called the Science and Technology Directorate, Counter-MANPADS System Program Office.

The agency is conducting an assessment program to evaluate and demonstrate emerging technology solutions that prove to be the most mature and promising in defeating the MANPAD threats to commercial aviation.

“Northrop Grumman is developing a range of approaches to provide a layered defense for airport security,” said Alexis Livanos, president of the Northrop Grumman Space Technology sector.

He referred to the other, aircraft-based anti-missile system that Northrop has developed.

“Our company has the unique capabilities required for this vital homeland security program,” Livanos said. “We offer the aircraft-based Directional Infrared Countermeasure (DIRCM) system, which the Department of Homeland Security is currently evaluating, in addition to the ground-based, high-energy laser system we proposed.”

In the near-term, DIRCM can be installed on the most vulnerable aircraft, the company noted. As the threat of attack continues to increase and new, more capable types of threat systems are introduced, however, the company said a layered defense can help mitigate the danger substantially to commercial aviation.

Skyguard uses a high-energy laser to physically destroy a wide range of anti-aircraft threats in the airport region, even with very short launch ranges, according to Mike McVey, vice president of directed energy systems for Northrop Grumman.

Northrop asserts that Skyguard technology is the only proven and tested non-DIRCM solution and is available in less than two years once a contract is received at approximately $30 million for each system.

Based on technology proven by the Tactical High Energy Laser (THEL) testbed at White Sands Missile Range, N.M., Skyguard has the specific capabilities needed to defeat supersonic threats, including speed-of-light operation, extreme precision, proven lethality and demonstrated operational safety, according to McVey.

He noted that THEL has shot down dozens of rockets in flight since 2000, including 122 mm Katyusha rockets, short-range ballistic missiles, artillery and several calibers of mortars.

Compatible with a range of packaging options, the Skyguard laser system would be placed at or near an airport to detect, track and destroy a variety of threats.

This capability will handle a full range of infrared seeker systems, and also is uniquely effective against command-guided missiles and other threats known to be in growing terrorist inventories, McVey added.

The Department of Homeland Security stated that the approaches it will evaluate in this procurement are limited to ground-based systems and aircraft-borne non-DIRCM systems.

These will involve alternative approaches employing emerging technologies that may have the potential for defeating MANPADs in a layered defense environment.

Congress has funded the Department of Homeland Security to assess alternative approaches to the current onboard DIRCM system demonstration currently underway, which the agency said is going very well.