Weapon specialists gather in front of a mock up of the Massive Ordnance Penetrator and the B-2 weapons load trainer Dec. 18 at Whitman Air Force Base, Mo. The MOP is approximately 20.5 feet long, with a 31.5-inch diameter and a total weight of slightly less than 30,000 pounds. The weapon will carry over 5,300 pounds of explosive material and will deliver more than 10 times the explosive power of its predecessor, the BLU-109. It is designed to penetrate up to 200 feet underground before exploding. (U.S. Air Force photo)