PALMDALE - The U.S. Air Force's B-2 stealth bomber would be able to attack and destroy an expanded set of hardened, deeply buried military targets using a new 30,000 pound-class penetrator weapon that Northrop Grumman has begun integrating on the aircraft. The company is doing the work under a seven-month, $2.5 million contract awarded June 1 by the Air Force's Aeronautical Systems Center, Wright Patterson AFB, Ohio. Northrop Grumman is the Air Force's prime contractor on the B-2, the flagship of the nation's long-range strike arsenal. The new Massive Ordnance Penetrator, which is being developed by The Boeing Company, is...