Coming soon: the B61-13

A new variant of the gravity bomb is in development.

By Whitney Spivey | August 1, 2024

A F-35 deploys a B61-12 joint test assembly.
The B61-13 will be deliverable by modern aircraft. A B61-12 joint test assembly is pictured here. DOD F-35 Joint Program Office

Congress has approved and funded a new variant of the B61 gravity bomb, the B61-13. As the national laboratory responsible for the B61 family of bombs, Los Alamos will oversee the design, development, testing, and eventual certification of the B61-13.

Upon completion, scheduled for the spring of 2026, the B61-13 will be deliverable by modern aircraft, including the forthcoming B-21 Raider stealth bomber. According to a news release from the Department of Defense (DOD), “the B61-13 will strengthen deterrence of adversaries and assurance of allies and partners by providing the President with additional options against certain harder and large-area military targets.”

The B61-13 will rely on the current, established production capabilities supporting the B61-12, a recently updated version of the B61 that has been in production since 2022 (B61-12s are entering the stockpile as they are completed). The B61-13 will incorporate the same modern safety, security, and accuracy features as the B61-12.

A B61-12 joint test assembly assembled at the Pantex Plant in Amarillo, Texas.
A B61-12 joint test assembly is assembled at the Pantex Plant in Amarillo, Texas. Photo: Pantex

“By taking advantage of ongoing B61-12 production activities, we will be able to quickly and effectively implement novel updates to the weapons system,” explains Dan Borovina, the B61 program manager at Los Alamos.

The yield (explosive power) of the B61-13 will be similar to that of the B61-7 (which is higher than the yield of the B61-12). The B61-13 will replace some of the B61-7s in the current stockpile and therefore will not increase the overall number of weapons in the U.S. stockpile.

“This initiative follows several months of review and consideration,” stated the DOD news release. “The fielding of the B61-13 is not in response to any specific current event; it reflects an ongoing assessment of a changing security environment.” ★