Image: ISC Defence Intelligence branded graphic. GBU-57 imagery available via U.S. Air Force public release.

DARPA seeks a shock-wave route to the next bunker buster

Technical Summary

The United States Defense Advanced Research Projects Agency (DARPA) has issued a Request for Information (RFI) seeking what it calls disruptive approaches to penetration mechanics and shock-wave control for the defeat of deeply buried, hardened targets. The RFI was reported on 28 and 29 May 2026 by RealClearDefense and Military Times, with responses due by 26 June 2026. The stated intent is to move beyond traditional mass-velocity scaling, the brute-force principle on which current bunker-busting munitions rely, toward mechanisms that deliberately shape, steer, amplify or suppress stress waves inside homogeneous and heterogeneous materials.

DARPA lists areas of interest including transient material-state manipulation under extreme loading, non-linear and anisotropic wave control, dynamic impedance matching, controlled failure initiation and progression, and the coupling of structural, material and geometric effects to achieve a step change in performance against complex targets. The agency also wants advances in architected or actively tunable materials, novel fabrication methods that embed function into structure, and advanced diagnostics able to resolve high-strain-rate phenomena in situ. The RFI does not call for a smaller weapon, but the explicit shift from kinetic mass to engineered wave physics opens the possibility of lighter penetrators that more aircraft could carry.

The government is explicitly interested in concepts that move beyond traditional mass-velocity scaling toward mechanisms that deliberately shape, steer, amplify, or suppress stress waves within homogeneous and heterogeneous materials. DARPA Request for Information, May 2026

Analysis of Effects

The current benchmark is the GBU-57A/B Massive Ordnance Penetrator (MOP), a roughly 13,600 kg (30,000 lb) weapon delivered by the B-2 Spirit. Open-source reporting puts its energetic fill at approximately 2,400 kg of AFX-757, an insensitive high explosive, although that figure is not officially confirmed and ISC carries it as reported rather than established. The MOP defeats hardened targets by converting a very large kinetic mass at impact velocity into penetration depth, then functioning a substantial main charge once it has burrowed through earth, rock or reinforced concrete. The defeat mechanism is therefore mass times velocity first, energetics second. DARPA is asking whether that order can be inverted, so that engineered shock-wave behaviour does the work that raw mass does today.

If the physics can be realised, the terminal-effects implications are considerable. Anisotropic wave control and dynamic impedance matching are, in plain terms, attempts to route a stress wave through a layered geology or a hardened structure so that energy is concentrated where it does the most damage rather than dissipated through the surrounding rock. The driver is geological as much as technical. Reporting cited in the source coverage indicates excavation of new facilities to depths of 80 to 100 m under hard granite, which sits at or beyond the reliable reach of existing penetrators. The operational context is the 22 June 2025 employment of 14 MOP weapons by seven B-2 aircraft against Iranian deeply buried sites, and the standing constraint that the United States Air Force fields only about 19 operational B-2 platforms able to carry the weapon.

Personnel and Safety Considerations

This item concerns a research solicitation, not a fielded round, so there is no packaged munition to classify and no storage or transport judgement to make. The relevant safety observation is forward-looking. Any munition that concentrates shock-wave energy by design will require a hazard classification regime that captures effects the current penetrator test base does not fully characterise, including off-axis stress-wave propagation and the behaviour of novel architected materials under initiation. Energetic fills, insensitive munitions compliance under STANAG 4439, and the eventual hazard division and compatibility group of any resulting weapon are all undefined at the RFI stage and would be set only once a physical design exists. No render-safe, handling or disposal guidance applies to a concept solicitation.

Data Gaps

Whether any candidate concept has reached hardware. Energetic fill chemistry and NEQ of any proposed penetrator. Target-set assumptions, including depth, overburden geology and structural hardening. Delivery platform and weapon mass class envisaged. Insensitive munitions and STANAG 4439 compliance posture. The GBU-57 explosive fill figure, which is widely reported but not officially confirmed. Programme funding line and transition path beyond the RFI.

Corrections & updates welcome. If you hold open-source data that refines or corrects any parameter in this article, please contact [email protected] citing the specific claim and your source. Verified corrections will be incorporated and credited in the revision history. AI-assisted technical assessment based on open-source material. Not a formal intelligence product.