Posted on 02/06/2025 9:09:46 PM PST by Red Badger
A new "smart fuze" for the GBU-57/B Massive Ordnance Penetrator has been tested and an issue tied to the B-2 stealth bomber has been fixed.
The U.S. Air Force quietly fixed a problem with the integration of the 30,000-pound class GBU-57/B Massive Ordnance Penetrator (MOP) bomb onto the B-2 Spirit stealth bomber last year. This is especially significant given that the B-2 is the only aircraft currently certified to operationally employ the MOP, a huge precision bunker buster specially designed to penetrate very deeply buried and fortified targets. As part of the integration work, the service also conducted an important test of a new “smart fuze” for the MOP to help improve the weapon’s effectiveness, even when the exact depth and positioning of the buried target are not definitively known.
The Pentagon’s Office of the Director of Test and Evaluation (DOT&E) included an update on developments regarding MOP in its most recent annual report, which covers work on various programs conducted during Fiscal Year 2024. The exact size of the current MOP stockpile is unknown, but it is understood to be relatively small. As of 2015, prime contractor Boeing had delivered at least 20 of the bombs, according to the Air Force. There have been reports of additional orders over the years and a story from Bloomberg in 2024 said that a facility in Oklahoma was being expanded to help triple or even quadruple the annual output of these bombs.
A GBU-57/B Massive Ordnance Penetrator bomb. USAF
The Air Force’s stock of MOPs has been upgraded multiple times over the years already and at least five variants are known to exist, the latest of which is the GBU-57F/B. Also, while the B-2 is the only platform approved for employing the bombs operationally, B-52 bombers have dropped the bombs during tests.
“The Air Force conducted two full-scale tests in FY24 to verify fixes to a B-2 integration issue,” DOT&E’s latest annual report, which was released last week, states. “The second of the two full-scale test events also used the LPSF [Large Penetrator Smart Fuze] in a full-scale testbed.”
A MOP mock-up sits inside a training device that simulates a B-2 bomb bay in 2007. USAF
“The Air Force established the LPSF Quick Reaction Capability program in August 2018 to respond to a validated urgent operational need, to integrate and qualify a smart fuze capability into the MOP that had been previously fielded as the Enhanced Threat Response [ETV] weapon modifications,” the report adds. “This upgrade, known as MOP Modification, provides the capability to hold at risk additional high-value HDBTs [hard and deeply buried targets] with limited threat intelligence.”
When it comes to bunker bombs, especially when employed against subterranean targets, effectiveness is not just about hitting the right mark, but also about detonating at the most optimal moment after burrowing down into the ground. Available intelligence about the target’s exact depth and general layout underground may be limited, as well. All of these issues are further magnified when it comes to the MOP, which is designed to penetrate especially deep, up to at least 200 feet (60 meters), according to publicly available data.
A graphic showing the potential penetration capabilities of the MOP from very early in the program. This shows a 60-foot penetrating depth, shallower than the 200-foot capability that has been reported since. What the weapon’s capabilities are currently are unknown. DOD via GlobalSecurity.org
What specific capabilities LPSF offers are unknown, but the U.S. military has publicly invested significant resources in the development of advanced void-sensing fuzes for smaller 2,000 and 5,000-pound class bunker buster bombs. A void-sensing fuze is designed to trigger when it detects a sufficiently large open space, such as a room in an underground facility. This can be further combined with a delay element to allow the bomb to break deeper into the target before detonating for maximum effect.
A graphic from the Hard Target Void Sensing Fuze (HTVSF) program, which focused on the development of advanced fuzes for bunker buster bombs smaller than MOP. DOD
LPSF could offer additional features to improve the overall effectiveness of the MOP.
DOT&E’s new report further highlights the challenges involved in testing new capabilities for the MOP even against subscale targets, let alone full-size threat representative ones.
“Due to program funding reprioritization, Defense Threat Reduction Agency (DTRA) contract challenges that affected the ability to construct targets to support testing, and modifications to the delivery platform, the MOP Modification program was unable to execute planned testing in FY21 and FY22,” per the report. “The Air Force rescheduled the test events into FY23 and FY24.”
A MOP test article in a tunnel at the U.S. Army’s White Sands Missile Range in 2007. DOD
“Changes made by DTRA to expedite the contracting and test plan review process have resulted in no material headway, and delays continue. While significantly delayed, the program was able to execute testing at the end of FY23 and in FY24,” the report continues. “Despite the delays in test execution and reductions in subscale testing, the program is proceeding with key performance milestones.”
“Subscale lethality testing was reduced in scope (by approximately 50 percent) due to funding redirection from the Air Force and test execution cost growth within DTRA. The reduced subscale test effort concluded in September 2024,” the report adds. “The DoD has limited test locations that allow for subscale and full-scale testbed construction, leading to high-demand and expensive, long-lead time, and custom-tailored testbed.”
A MOP seen right before hitting the ground during a previous test. DOD
The general value of having a non-nuclear, very deep-penetrating weapon like MOP in the U.S. military’s arsenal is only increasing. America’s near-peer competitors China and Russia continue to build new hardened and/or underground facilities, including bases with deep caverns for aircraft and submarines, which would be important in the event that a high-end conflict erupts. Just last week, the Financial Times published a detailed report on a new 1,500-acre command center complex with a major subterranean component that the Chinese People’s Liberation Army (PLA) is building in the western end of the country’s sprawling capital Beijing.
Other smaller potential adversaries, especially Iran and North Korea, have been increasingly pushing critical facilities underground in no small part because of the threat of strikes from countries like the United States. A report from The Associated Press in 2023 notably highlighted concerns that new underground additions to Iran’s Natanz nuclear site could be out of the reach of MOP.
Last year, Israeli forces also conducted a dramatic commando raid that destroyed an underground missile production facility in Syria that had been built with Iranian assistance, which you can read about here. That operation underscored the challenges of neutralizing these kinds of deeply buried and hardened sites and signaled, especially to Iran, Israel’s willingness and ability to take such steps to do so.
VIDEO AT LINK..................
MOP, in combination with the stealth B-2, also gives the U.S. military a unique option for prosecuting deeply buried and hardened targets located in very heavily defended areas. The forthcoming B-21 Raider stealth bomber will offer even more capability in this regard. The Air Force has also been looking at adding new 5,000-pound class GBU-72/A bunker buster bombs to the B-2’s arsenal in the meantime.
The Pentagon explicitly highlighted all of this in a statement following B-2 strikes on “hardened underground weapons storage locations in Houthi-controlled areas of Yemen” last October, which stressed “the United States’ ability to target facilities that our adversaries seek to keep out of reach, no matter how deeply buried underground, hardened, or fortified.” As TWZ noted at the time, the use of B-2s in this case was clearly meant to send signals beyond Yemen, particularly to Iran.
All of this underscores the importance of the LPSF and other upgrades to the MOP, as well as ongoing testing to validate those improvements.
Contact the author: joe@twz.com
AVIATION PING!.....................
This is something I NEVER would see or know about on my own.
Thanks for posting...I’m actuaslly going to read the article :)
Disastrous to the endangered “Banded Desert Wombat” habitat. A federal judge will soon be issuing an injunction on the use. (Unless it’s intended use is against deplorable Americans with deep basements)
“ A report from The Associated Press in 2023 notably highlighted concerns that new underground additions to Iran’s Natanz nuclear site could be out of the reach of MOP.”
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Perhaps out of reach of one, but not immune to two or more. These rallies have gotten fairly adept at dropping one bomb, and then delivering another one to the exact same target within seconds. It allows for deeper penetration, and is apparently how they dug out the leader of Hezbollah a few months ago.
It's not a simple thing to make a component that can withstand that kind of impact.
That is one large popper.
You can run, but...
wy69
"I like your MOP!" she said. "No, that's my LPSF" I replied.
Specially designed to flatten nuclear bunkers buried under mountains. Made easier when the target country lost its radar and air defenses.
In the 1950s we could put a small atomic bomb in an artillery shell: could we do that inside a penetrating bomb like this?
Goodbye Iranian nuclear weapons program.
For accuracy, the bombs had to be dropped precisely from a pre-determined height (usually 20,000 ft (6,100 m)).[6] They would free-fall for around 30 seconds until, at 5,000 ft (1,500 m), the rockets were ignited, causing the tail section to be expelled.[6] The rocket burn lasted for three seconds[7] and added 300 ft/s (91 m/s) to the bomb’s speed, giving a final impact speed of 1,450 ft/s (440 m/s; 990 mph),[7] approximately Mach 1.29.[a] Post-war tests demonstrated that the bombs were able to penetrate a 14-foot-8-inch (4.47 m) thick concrete roof,[8] with the predicted (but untested) ability to penetrate 16 feet 8 inches (5.08 m) of concrete.[8]
https://en.m.wikipedia.org/wiki/Bunker_buster
Be a nice start for cartel resolution.
SHHHHHHHHH!......(of course we can!)........................
Why didn’t they test it on the Yucca Mountain radioactive waste facility? It woukd make a perfect test site since Uncle Sugar poured $ Billions into it and now it sits used. Talk about a real money pit.
Interesting that this article comes out right as Iran wants to negotiate, but Trump wants to end their nuke program
Meant to say its sits unused...
“Why didn’t they test it on the Yucca Mountain radioactive waste facility? “
Because it’s not vacant or unused......................😏
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