It took close to five years of development and 14 months of live testing for Northrop Grumman to prove it could build a system that airline pilots might use to deflect terrorist missiles.
Selling it may be even tougher.
Congress would have to require the cash-strapped aviation industry to install the nearly $1 million systems on each of the nation's 7,800 passenger and cargo aircraft. The airlines and pilot groups say they shouldn't pay for expensive technology that doesn't address the most pressing terrorist threats.
"There's going to have to be a fundamental decision within the U.S. government that says this is a real threat," James F. Pitts, president of the defense contractor's electronic systems division, said yesterday at a briefing at Baltimore-Washington International Thurgood Marshall Airport.
"The commercial airlines have to decide to do it or the government is going to have to fund this, to pay the airlines to put on a mandated requirement."
Northrop's laser-based Guardian system is designed to track and then deflect heat-seeking, shoulder-fired missiles - weapons becoming popular with insurgent groups in the world's hot spots though not known to have been used against a commercial aircraft in the United States. Intense light beams - not explosives - target approaching missiles, directing their path away from the plane.
El Al Israel Airlines has also developed an anti-missile system, but it uses a different, flare-based technology, Pitts said.
After terrorists fired two SA-7 missiles that nearly hit an Israeli passenger jet in Kenya in November 2002, Congress ordered the Department of Homeland Security to develop and test an anti-missile system that could be installed on commercial aircraft.
Northrop Grumman Corp. said it has received $105 million from the federal government since the initiative launched in late 2003. It manufactured the Guardian system's missile sensors in Linthicum.
London-based BAE Systems has received a similar amount for a passenger aircraft defense system, which will be tested on flights made by three American Airlines planes later this spring.
Rep. James Langevin, chair of the House Homeland Security subcommittee with oversight of the anti-missile program, said more intelligence is needed to prove the systems will address a real threat to the airline industry.
"We have to be realistic about both the threats and the maturity of the technology, and also have to be able to answer the question of how it will be paid for and when's the soonest we can get it deployed," said Langevin, a Democrat from Rhode Island.
Northrop is hoping that the Department of Defense adopts the technology for its Civil Reserve Air Fleet, which consists of at least 800 airplanes that airlines contract out to the Pentagon to fly troops and supplies to war zones.
Because the 7-foot-long, 600-pound Guardian system is detachable, the department could purchase fewer pods and bolt them onto planes when they fly to more threatening destinations, rather than outfitting every plane with one, said Thomas E. Zoeller, president of the National Air Carrier Association, whose members' planes are used for such military flights.
The Air Transport Association, which represents most commercial carriers, and the Air Line Pilots Association remain critics of the effort. The industry associations worry that the anti-missile systems will increase energy consumption and require disruptive maintenance.
During a 14-month test of the system on FedEx cargo jets, fuel costs increased less than 1 percent, Northrop Grumman said.
Making cockpit doors hijack-proof, screening cargo for explosives more effectively and controlling the perimeters of airports are more urgent - and less expensive - anti-terrorism needs, said Bob Hesselbein, chairman of the national security committee for the Air Line Pilots Association.
"We don't really feel that there's a significant threat, a flurry of shoulder-fired missiles that will be fired within the U.S.," Hesselbein said.
"We want to make sure that the limited security dollars are spent in the manner that will create the most good, be the most deterrent."
If it mandates anti-missile systems, the federal government should pay the full cost, said John E. Pike, a defense analyst with Alexandria, Va.-based GlobalSecurity.org.