Northrop-Grumman, leading manufacturer of combat lasers, believes these weapons are only a few years away from battlefield use. To that end, the company has set up a new divisions to develop and build the battle lasers. This optimism was caused by two successful tests last year. In one, a solid state laser shot down a mortar round. In another, a much more powerful chemical laser, firing from a customized B-747, hit a missile type target. Nearly half a century of engineering work has produced thousands of improvements, and a few breakthroughs, in making the lasers more powerful, accurate and lethal. More efficient energy storage has made it possible to use lighter, shorter range ground based lasers effective against smaller targets like mortar shells and short-range rockets. Northrops move is an indication that the company feels confident enough to gamble its own money, instead of what they get for government research contracts, to produce useful laser weapons. The high energy airborne laser would not only be useful against ballistic missiles. Enemy aircraft and space satellites would also be at risk.