Explosives on the Moon: Revisiting the Forgotten Tool for Construction and Seismic Engineering
- Roberto Moraes
- Sep 9
- 12 min read
Explosives are among the oldest engineered tools for reshaping the ground. On Earth, they have enabled dam abutments, tunnel breakthroughs, open-pit mines, and seismic surveys. On the Moon, they have barely been tested. Apart from the small seismic charges deployed during Apollo, no serious attempt has been made to use chemical energy for excavation, shielding, or rock fragmentation. This absence is striking, because the same constraints that make mechanical excavation difficult in the lunar environment, low gravity, vacuum, extreme temperature cycles, and abrasive soils, are precisely where controlled blasting could reduce time, energy demand, and equipment complexity.
Lunar construction discussions today often focus on mechanical excavation, sintering, or robotic grading. Yet explosives remain the only method capable of rapidly creating craters, trenches, and cavities with minimal equipment. They are also the most proven way to generate controlled seismic signals. The technology exists, the physics are understood, but the applications have stalled. The result is a gap: we know explosives can work, but we do not know how they perform when scaled to construction-size problems on the Moon.
This article examines where explosives fit into lunar engineering today, with a focus on construction excavation, seismic profiling, and quarrying for resources. It draws on past proposals, Apollo-era seismic results, and modern advances in insensitive high explosives and nano-energetics. It also outlines the research gaps that remain before blasting can be considered a reliable tool for lunar bases.
Construction Excavation with Explosives
Excavation is the first step in building lunar infrastructure. Whether for a landing pad, a protective berm, or a reactor emplacement, the ground must be reshaped quickly and reliably. Mechanical excavation with dozers, graders, or drilling rigs is constrained by wear, power demand, and logistics. Controlled blasting, in contrast, concentrates stored chemical energy into a single event that can move and fracture volumes of regolith orders of magnitude faster than any mechanical process.
Early engineering studies identified the potential of row charges placed at shallow depth to produce interconnected craters. When properly spaced, the displaced material forms ridges that can act as berms or partial shielding walls. In a lunar base scenario, this method could be used to build a protective barrier around a habitat or landing pad within a single lunar day, instead of relying on weeks of incremental grading.
For nuclear surface power, emplacement below grade is a straightforward way to provide natural shielding. A single contained detonation could create a pit large enough to house a modular reactor, with the excavated material reused as overburden. This approach minimizes the need for heavy excavation equipment and offers a rapid method to achieve the required geometry.
Linear cutting charges, already standard in Earth construction, can be adapted for lunar conditions. These would allow precise trenching for utility corridors, regolith conveyance systems, or anchoring foundations. Unlike cratering shots, shaped charges minimize ejecta scatter, which is critical near sensitive assets.
Explosives Under Lunar Environmental Conditions
The Moon imposes environmental extremes that no terrestrial blasting practice directly replicates. These conditions determine which explosive formulations are viable, how they must be stored, and what risks accompany their use.
On Earth, part of the energy released by an explosion propagates as an airblast. On the Moon, with no atmosphere, there is no blast wave. The chemical energy couples almost entirely into the ground and into ejecta. This amplifies crater formation efficiency but extends debris throw distances six-fold compared to Earth. Without an atmosphere, fumes dissipate instantly, so there is no toxic hazard, but the absence of confinement makes charge containment and stemming essential to achieve useful ground penetration.
Surface temperatures range from –170 °C at night to +120 °C during the lunar day. Traditional dynamite or slurry-based explosives degrade under repeated freeze–thaw cycles, suffering crystallization, exudation, or casing rupture. Modern insensitive high explosives (IHEs) such as TATB or FOX-7 retain chemical stability across broad thermal ranges and are not prone to decomposition in vacuum. These formulations, combined with sealed casings, offer reliable detonation performance even under lunar thermal cycling.
Solar particle events and constant galactic cosmic radiation add long-term stress to energetic compounds. Over months of exposure, radiation can alter molecular bonds, increasing sensitivity or reducing performance. Earth-based explosives are not designed for this regime. Insensitive formulations with radiation-hardened binders, or nano-energetic composites with minimal volatile content, are the most realistic candidates for lunar storage.
Conventional detonators and boosters require sealed housings to prevent outgassing. On the Moon, explosive charges must be pre-encapsulated in hermetic casings. Robotic emplacement would likely use modular cartridges inserted into pre-drilled boreholes. Initiation systems must be shielded against vacuum-induced arcing and thermal extremes.
Seismic Investigation with Explosives
Seismic profiling is the only application where explosives have already been used on the Moon. The Apollo 14 and Apollo 16 missions deployed small charges, ranging from a few hundred grams to several kilograms, as part of the Active Seismic Experiment (ASE) and the Lunar Seismic Profiling Experiment (LSPE). These experiments confirmed that chemical detonations could be initiated reliably in vacuum and provided valuable data on near-surface velocity profiles and regolith layering.
The charges were placed on the surface or launched from a mortar system to distances of up to 1.5 kilometers. Hexanitrostilbene (HNS), a thermally stable high explosive, was chosen for its insensitivity and ability to withstand storage in vacuum. Seismic detectors recorded distinct arrivals, proving that explosive energy could couple into the lunar ground with predictable efficiency. These were small-scale experiments, but they validated two essential points: explosives can function under lunar conditions, and the seismic response of the regolith can be mapped with controlled sources.
Seismic surveys remain critical for construction. Any landing site or base requires knowledge of regolith thickness, layering, and mechanical properties down to several tens of meters. Mechanical vibrators or hammer sources are feasible but limited in depth penetration. Controlled explosive charges remain the most effective method to generate strong seismic waves capable of imaging both regolith and underlying megaregolith.
No mission since Apollo has repeated explosive seismic surveys. Remote sensing has advanced, but seismic remains the only direct way to measure subsurface stratigraphy. Modern insensitive high explosives, nano-energetic boosters, and robotic emplacement systems could extend Apollo’s approach to larger arrays, deeper penetration, and higher resolution. This capability is particularly relevant for:
Landing pad site characterization: verifying subgrade competence.
Excavation planning: mapping depth to dense layers that influence blasting outcomes.
Resource targeting: identifying voids, fractures, or ice-bearing horizons.
Research Gap
Despite the Apollo demonstration, seismic blasting remains underdeveloped. No dataset exists for larger charge sizes, no scaling laws have been validated for lunar vacuum conditions, and no robotic emplacement methods have been tested. What is known is sufficient to prove feasibility; what is missing is the systematic development needed to make it a reliable engineering tool.
Future research should address:
Scaling Laws in Vacuum and Low Gravity
- Conduct controlled experiments with charges from 1–50 kg in lunar regolith simulants under vacuum and partial gravity conditions.
- Derive empirical relations between charge size, depth of burial, and seismic signal strength.
- Validate numerical hydrocode simulations with physical data.
Robotic Emplacement and Initiation
- Develop autonomous drilling and placement systems capable of inserting pre-packaged explosive cartridges into boreholes.
- Test initiation reliability under vacuum, radiation, and temperature cycles.
- Integrate blasting modules into rover platforms to extend survey reach.
3. Sensor Array Integration
- Optimize seismic sensor layouts for use with controlled blasting in the lunar environment.
- Assess the trade-offs between shallow high-density arrays vs. wide sparse networks.
- Explore co-deployment strategies with construction or ISRU operations.
4. Coupling Efficiency in Regolith and Megaregolith
- Characterize how seismic energy propagates through unconsolidated regolith, compacted layers, and fractured bedrock analogs.
- Quantify attenuation and dispersion to refine interpretations of seismic profiles.
- Model ejecta trajectories and ground shock propagation for seismic-size charges.
- Design blast containment measures to protect nearby equipment and habitats.
6. Dual-Use Applications
- Investigate how seismic blasting can be integrated into broader construction goals. For example: a crater shot that provides both subsurface velocity data and an excavation cavity for later use.
Quarrying and Resource Extraction
The potential of explosives extends beyond construction and seismic profiling. Controlled blasting is one of the most effective methods of breaking rock and exposing ore bodies on Earth, and the same principle can be adapted to the Moon. Quarrying through blasting could accelerate access to bedrock, expose mineralized zones, and produce regolith fragments suitable as feedstock for in-situ resource utilization (ISRU).
Early lunar engineering studies proposed large-yield shots to remove overburden or to open hillside quarries. Other methods included coyote blasts (shallow pits filled with charges) and block caving using vertical boreholes. The aim was not fine fragmentation but rather rapid access to useful rock masses. While these concepts were never tested in space, they anticipated ISRU demands that are now at the center of lunar planning.
ISRU operations require steady volumes of feedstock: basalt fragments for oxygen extraction, ilmenite-rich rocks for metals, and potentially icy regolith for volatiles. Mechanical mining can achieve this incrementally, but blasting offers two advantages:
Energy efficiency: Recent fragmentation models suggest explosives on the Moon require four to five times less charge mass per cubic meter than on Earth, due to reduced gravity and altered stress distribution.
Scale: A single detonation can fracture thousands of cubic meters, providing stockpiles for months of ISRU processing.
Technical Considerations:
Fragment Size Distribution: For ISRU, fine particle sizes are favorable, but dust control is critical. Explosives can be tailored to optimize fragmentation, though no lunar-scale tests have been performed.
Ejecta Hazard: Quarry blasting must be conducted at safe stand-off distances or inside shielded zones to avoid damaging nearby infrastructure.
Containment: Subsurface blasting, or blasting into pre-dug pits, can limit ejecta travel while still generating usable fragments.
Material Handling: Blasting must be integrated with robotic loaders and conveyors designed for vacuum and reduced gravity.
Research Gap
The quarrying potential of explosives remains almost entirely unexplored. Key areas requiring investigation include:
Fragmentation Models Under Lunar Conditions
a. Laboratory and computational studies must be extended to in-situ experiments.
b. Measure fragment size distributions, particle velocity fields, and dust cloud dynamics.
Blast Geometry for ISRU Feedstock
c. Test charge arrangements that produce controlled fragmentation rather than uncontrolled cratering.
d. Explore small, repeated blasts vs. fewer large-scale detonations for feedstock optimization.
Dust and Ejecta Control
e. Develop predictive models for ejecta range and particle distribution.
f. Test mitigation methods such as stemming, blast mats, or regolith containment berms.
Integration with ISRU Systems
g. Assess how blasted rock interacts with crushers, conveyors, and chemical reactors.
h. Define fragment size and cleanliness requirements for oxygen extraction or metallurgy.
Safety and Infrastructure Compatibility
i. Establish exclusion zones for quarrying operations near bases.
j. Evaluate structural shock effects on equipment foundations and landing pads.
Transporting Explosives to the Moon: The Apollo Precedent
Explosive use on the Moon wasn’t limited to lunar experiments, it also extended to constrained, highly secure transport. Apollo missions that deployed seismic charges took meticulous care in packaging, handling, and delivery, a process worth revisiting as a guideline for future lunar blasting initiatives.
HNS-Teflon Seismic Charges – Packaging and Transport
For Apollo 17’s Lunar Seismic Profiling Experiment (LSPE), eight explosive packages, a blend of hexanitrostilbene (HNS) with Teflon binder, were carried from Earth to the lunar surface aboard the Lunar Module. These charges were designed for vacuum compatibility and thermal cycling resilience. Despite minor thermal-induced cracking, testing demonstrated that performance remained unaffected, and all eight charges functioned successfully when detonated remotely.
Safety and Arming Mechanisms
The LSPE charges incorporated multi-layered safety features. Each package was equipped with:
A pull-pin-safe/arm plate,
A timed-release arming mechanism,
A secondary timer, and
A thermal battery–powered receiver accepting only a specific command to detonate.
These measures ensured that arming could only occur under very specific conditions—eliminating premature activation risk and allowing the charges to be safely handled during transport, deployment, and remote initiation.
Astronauts deployed the explosive packages during EVAs to designated surface locations. After departure from the site, Earth transmitted detonation commands to the charges, which then self-armed via the timed mechanisms and thermal batteries. This demonstrated a successful closed-loop system of human-safe delivery and purely remote detonation, a valuable blueprint for future automated deployment strategies.
Engineering Takeaways for Lunar Blasting Operations
Packaging and Stability: Future explosives must prioritize environmental resilience, thermal cycling resistance and vacuum integrity being non-negotiables.
Safe/Arm Architecture: Apollo’s redundant design illustrates how safety, reliability, and delayed arming can coexist within small explosive packages.
Remote Activation Protocol: A remote initiation system, activated only after secure arming, provides crucial safety margins, a model that robotics-based systems could adopt and improve.
Safety, Ground Shock, and Ejecta Hazards
The principal risks of blasting on the Moon are not chemical instability or airblast, but ground shock and high-velocity ejecta. Both present engineering hazards to nearby infrastructure and must be managed if explosives are to become reliable construction tools.
On Earth, blast-induced ground shock is attenuated by soil damping and layering. Lunar regolith, being dry, granular, and vacuum-bound, transmits shock differently. Small Apollo seismic shots confirmed that the energy coupled efficiently into the regolith and megaregolith, producing clear seismic arrivals over kilometer distances. While this efficiency is useful for subsurface exploration, it means structures in the vicinity of larger charges could experience stronger peak particle velocities than their terrestrial equivalents.
Implication for bases: Blast exclusion zones will need to be larger, unless energy is carefully contained.
Research need: Scaling laws for regolith shock propagation must be validated experimentally, as no large charges have ever been detonated on the Moon.
Ejecta Hazards
Without an atmosphere, ejecta fragments travel far. Modeling suggests debris can reach six times farther than equivalent Earth blasts, with particle trajectories unaffected by drag. For construction blasting, this presents two hazards:
Equipment damage: Rovers, landers, and habitats risk impact by projectiles even at extended distances.
Surface contamination: Dust clouds can coat sensitive optics, radiators, and solar panels.
Mitigation concepts include:
Subsurface emplacement to contain ejecta.
Blast mats or regolith covers placed over charges.
Shield berms constructed in advance to intercept fragments.
Safety Protocols and Stand-Off Distances
Apollo charges were small (grams to kilograms) and deployed far from the Lunar Module, minimizing risk. Future engineering blasts for excavation or quarrying will operate in the 10–100 kg range, where ejecta throw and ground motion become operationally significant. Safety protocols must establish minimum stand-off distances, orientation of sensitive equipment, and shield requirements.
Integration with Robotics
Unlike the Apollo approach, which assumed astronaut handling, lunar blasting today would rely on robotic emplacement. Remote placement not only reduces crew risk but also allows systematic use of stemming, shielding, and controlled delay detonations. The challenge is to design robotic systems that can withstand dust, thermal cycling, and the mechanical precision required for reliable charge placement.
Research Gap Radar (integrated version)
Explosives have already been proven once on the Moon. The Apollo seismic charges demonstrated that detonation in vacuum, under thermal cycling and radiation exposure, is not only possible but reliable. What has not been tested is their role in construction, quarrying, or large-scale site preparation, the very activities where blasting has reshaped the Earth for centuries.
The physics is favorable: without an atmosphere, chemical energy couples directly into the ground, producing efficient seismic signals and deep craters. The logistics are manageable: insensitive high explosives and nano-energetics offer stability across lunar extremes, while robotic emplacement eliminates risks to astronauts. The applications are clear: rapid berm formation, reactor pits, seismic arrays, and fragmentation for ISRU.
The gap is not technical imagination but experimental commitment. No mission since Apollo has tested blasting beyond a scientific demonstration. Until controlled lunar-scale trials are carried out, explosives remain an underutilized resource, a tool with unmatched potential to accelerate base construction, but left in the background of lunar planning.
If future missions are serious about infrastructure, explosives should be part of the test matrix. A few kilograms of sealed charges, deployed robotically, could answer half a century of unanswered questions and open a new chapter in lunar ground engineering.
About the Author
Roberto de Moraes is a senior geotechnical engineer with three decades of experience in excavation, tunneling, and underground construction. He is the founder of SpaceGeotech.org, a technical platform dedicated to advancing lunar geotechnical engineering and site preparation frameworks. His work bridges terrestrial field practice with lunar applications, proposing methods for excavation zoning, spoil management, and foundation design in extreme environments.
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