The US Air Force has launched a new contracting action linked to continued production and sustainment of the GBU-57 Massive Ordnance Penetrator (MOP), a heavyweight precision-guided weapon designed to destroy hardened and deeply buried targets.
A notice published on the US government’s SAM.gov portal lists an active contracting opportunity titled “Massive Ordnance Penetrator (MOP) Production and Support” under Notice ID EBDA_GBU-57. The contract award date is listed as 10 February 2026, under contract number FA868126CB001, issued through the Department of the Air Force.
The MOP is one of the largest conventional bombs in the US inventory, weighing around 30,000 pounds and developed specifically for penetrating reinforced underground facilities. It is associated with the BLU-127 bomb body, and is designed to survive high-speed impact before detonating below the surface. Public technical information describes the weapon as using a modular design intended to allow upgrades over time.
The bomb’s tail assembly includes a GPS-assisted inertial navigation guidance package, enabling precision strike capability. The weapon is also reported to use a “smart” fuse capable of detonating at a selected depth, allowing it to target underground bunkers, tunnels, and reinforced structures.
Open-source reporting has long associated the GBU-57 with the B-2 Spirit, which is widely considered the only operational aircraft configured to carry the weapon in combat, though it has also been linked to future integration with the B-21 Raider. While the public Justification & Approval document is heavily redacted, the contract title and classification indicate the Air Force is continuing efforts to replenish or expand the stockpile of the Massive Ordnance Penetrator, amid ongoing focus on the ability to strike hardened facilities in high-threat environments.
A slightly Improved Grandslam really.
Barnes Wallis would be impressed, to be fair it is nearly 50% more massive.
Grand Slam was a 22,000lb RAF earthquake bomb, so it has taken a long time to better the British (Barnes Wallis) invention.
Yes, It’s 80 odd years now and I know this MOB has been around a while but BW was way ahead of the game.
Funny that he only made one film !!!
I’m not usually one for obsessing over length and girth… but that photo really puts things into perspective.
Out of curiosity I looked up the specs:
• Length, 6.2 metres
• Diameter, 0.8 metres
• Bomb body weight, around 12,300 kg
• Total explosive weight, approximately 2,400 kg
• AFX-757, just over 2,080 kg
• PBXN-114, about 340 kg
Pretty much the same weight as an empty F-35A.
“Geek” lol 😁
Sorry, “It’s my manner sir”.
(T.E.Lawrence (( I visited his grave a few weeks back, nice little plot in Moreton)).
I know, right! Luckily it’s Friday, so I can do something a bit more ‘manly’ later and head to the pub to redeem myself for all this geekiness. Seriously though, what a unit the MOP is — I can totally see why they skipped a lighter grey and went straight for the black paint.
There are not really many targets for it outside of china.