The Airborne Laser (ABL), a defensive system that kills enemy missiles shortly after they launch, may have other applications such as air-to-air combat against enemy planes, killing enemy cruise missiles or hitting other threats, briefers with The Boeing Co. [BA] said.

Currently, the ABL has undergone most of its years-long development, leading this year to a crucial test where the laser-in-a-plane will shoot down a target missile for the first time.

The system involves a heavily-modified 747-400 jumbo jet contributed by prime contractor and integrator Boeing, containing a laser system by Northrop Grumman Corp. [NOC] and a beam control/fire control system by Lockheed Martin Corp. [LMT].

However, some Democrats in Congress have attempted to slash ABL funding over the past two years, and another attempt is expected this year as lawmakers write the budget for the fiscal year ending Sept. 30, 2010.

Boeing is countering by pointing out the multiple advantages of the ABL: the lethal beam moves at the speed of light to zap enemy missiles, and it has a virtually unlimited magazine, able to keep hitting an enemy missile until it is annihilated.

Thus far, the program has cost American taxpayers about $5 billion, money that would be wasted if the program is killed, according to comments by Boeing officials at a news media briefing at Boeing offices.

Further, ABL strikes enemy missiles soon after launch, before they have the opportunity to spew forth multiple warheads, confusing chaff or decoys, and long before they can come anywhere near American or allied target locations. That means if the ABL ever didn’t kill the missile, there still would be an opportunity for other U.S. missile defense systems to hit the threat later in its trajectory.

Another selling point to provide Congress will be that ABL, while admittedly "expensive" for the planes, is extremely cheap to operate.

While a single interceptor missile in another system might cost hundreds of thousands of dollars, the ABL can shoot at length, at multiple threats, for the cost of $60,000 to $70,000 for an entire chemical oxygen iodine laser load, a briefer said, responding to a question from Space & Missile Defense Report.

The salient question here, a briefer said, isn’t the fact that an ABL plane is expensive, or that several planes would be required to provide a missile defense shield. Rather, the germane point is that the ABL "will bring military utility to the table" in a new type of weapon for the U.S. armed forces.