The Boeing Co., www.boeing.com

Anyone working in underground nuclear facilities in Iran, North Korea, or any other nation hostile to the U.S. has one more thing to worry about: a GBU-57A/B Massive Ordnance Penetrator crashing through the roof and exploding. The bomb, the Pentagon’s latest bunker buster developed at Boeing, Chicago, measures 20 ft from base to nose and weighs 30,000 lb, 10 times as heavy as its predecessor, the BLU-109. And almost 20% of its weight is comprised of high explosives. The bomb is so heavy, however, that only two U.S. aircraft can deliver it, the B-52 and the B-2. At least one B-2 has been modified to carry two of the GPS-guided bombs.

The bomb was developed specifically for underground bunkers. It will use its weight and kinetic energy to pierce through the earth and any hardened structure before exploding. The warhead is rumored to be made of a high-performance steel alloy that will survive high-speed impacts into hardened concrete bunkers. According to the Pentagon, the bomb will penetrate 200 ft (61 m) of 5,000-psi reinforced concrete, or 26 ft (8 m) of 10,000-psi reinforced concrete, or 130 ft (40 m) of moderately hard rock. The military received funding ($68 million) for 10 of these bombs.