Air Force Reveals Designation for Next-Gen Bunker Buster, Seeks Sources

The Air Force has dubbed its follow-on to the Massive Ordnance Penetrator the GBU-76/B and is seeking contractors to potentially help design, build, and support the next-generation bunker-busting bomb.

Air Force Materiel Command posted a sources sought notice for the Next-Generation Penetrator, the alternate name for the GBU-76/B, on June 1.

The GBU-76/B is intended to succeed the GBU-57 MOP, which the Air Force used in June 2025 to strike deeply buried Iranian nuclear facilities as part of Operation Midnight Hammer. It was the first time the 30,000-pound, 20-foot MOP had been used in operations.

The MOP uses its steel casing and tremendous mass to penetrate through rock, steel, concrete, or other hardened materials before detonating to destroy deeply buried laboratories, storage facilities, command centers, or other key targets. Its successor is expected to operate in a similar fashion.

The sources sought notice says the Air Force Life Cycle Management Center’s weapons directorate at Eglin Air Force Base, Fla., aims to award a multiple-award indefinite delivery, indefinite quantity, or IDIQ, contract for research and development, production, testing, and delivery of the GBU-76.

The Air Force wants interested vendors to submit a response that shows how they would be able to support the design, production, testing, and beddown of components and activities related to the GBU-76’s development, performance, and sustainment. That could include engineering, modeling, simulation and analysis, production, hardware procurement, software and aircraft integration, and numerous other tasks, the notice said.

The notice is the latest step for the Next-Generation Penetrator. Last September, the Air Force awarded a 24-month contract to Applied Research Associates and its partner Boeing to produce a prototype of the bomb. That built on a 2024 request for information that stated the Air Force wanted a prototype that:

Weighed no more than 22,000 pounds
Had accuracy within 2.2 meters 90 percent of the time 
Blast, fragmentation, and penetration effects
Possible integration of embedded fuze technology 

The most recent sources sought notice said that in their responses, vendors should clearly demonstrate they understand how to create large penetrator warhead systems weighing roughly between 20,000 and 30,000 pounds, have carried out such tasks for the government for at least five years, and have the equipment, facilities, personnel and other resources to do the job.

Responses are due June 16. The Air Force said small businesses can submit a response showing how they could carry out a portion of the program requirement, even if they can’t carry out the whole requirement. But foreign-owned or controlled firms will not be considered for the Next-Generation Penetrator program, the notice said.

The current MOP can only be carried by B-2 Spirit stealth bombers, which carried out the Midnight Hammer strikes. But should the Air Force pursue a Next-Generation Penetrator that weighs thousands of pounds less, it could open the door for the B-21 Raider—which will be smaller than the B-2—to carry more than one of the penetrating weapons, for example.