The U.S. Air Force problems with its Airborne Laser (ABL) program continue to escalate, and Congress is beginning to mutter about cancellation. Since the program began in 1996, there have been a billion dollars in cost overruns. An additional billion dollars will apparently be needed before the ABL is ready for testing next year. Then, according to current estimates, another three billion dollars will be needed between 2005 and 2009, with no firm date on when the ABL would be ready for actual deployment. The ABL consists of a large laser, mounted in a modified B-747 aircraft, which operates at 40,000 feet and fires a laser beam that can knock down an ICBMs as they lift off into space by damaging the fuel system or rocket motors. While nice in concept, lasers have a hard time traveling long distances through the atmosphere (even the thin at atmosphere at 40,000 feet) and causing significant damage. The air force wants more money to continue attempts to solve these technical problems.