Engineers at the United States' nuclear weapons lab in Albuquerque, New Mexico, have spent the past few years designing and testing the B61-12, a high-tech addition to our nation's atomic arsenal. Unlike the free-fall gravity bombs it will replace, the B61-12 is a guided nuclear bomb. A new tail kit assembly, made by Boeing, enables the bomb to hit targets far more precisely than its predecessors.
Using "Dial-a-yield" technology, the bomb's explosive force can be adjusted before launch from a high of 50,000 tons of TNT equivalent to a low of 300 tons—that's 98 percent smaller than the bomb dropped on Hiroshima 70 years ago.
Despite these innovations, the government doesn't consider the B61-12 to be a new weapon but simply an upgrade. In the past, Congress has rejected funding for similar weapons, reasoning that more accurate, less powerful bombs were more likely to be used. In 2010, the Obama administration announced that it would not make any nuclear weapons with new capabilities. The White House and Pentagon insist that the B61-12 won't violate that pledge.
The B61-12 could be deployed by the new generation of F-35 fighter jets, a prospect that worries Hans Kristensen, a nuclear weapons expert at the Federation of American Scientists. "If the Russians put out a guided nuclear bomb on a stealthy fighter that could sneak through air defenses, would that add to the perception here that they were lowering the threshold for the use of nuclear weapons?" he asks. "Absolutely."
So far, most of the criticism of B61-12 has focused on its price tag. Once full production commences in 2020, the program will cost more than $11 billion for about 400 to 480 bombs—more than double the original estimate, making it the most expensive nuclear bomb ever built.