NASA’s DART Could Be Outmuscled by Buried Asteroid Blast Simulations
NASA proved in 2022 that a spacecraft can deliberately nudge an asteroid. Now a new simulation study argues that a much stronger option may be possible for the cases where time is short: first dig a crater, then place a nuclear device inside it so more of the blast pushes into the rock instead of venting into space.
The comparison matters because the gap is not just academic. A DART-style kinetic impact is already demonstrated in flight, but the new two-spacecraft concept is aimed at the harder corner of planetary defense: larger asteroids or threats discovered with too little warning for a relatively gentle push to do enough.
In the reported design, one uncrewed spacecraft would strike the asteroid with a heavy penetrator to create a crater. A second spacecraft would then place a warhead into that cavity before detonation. The basic engineering idea is straightforward: burial improves energy coupling. Instead of wasting more of the explosion outward into vacuum, the crater walls and overlying material force more of that energy into fracturing and accelerating the asteroid.
That is the core difference from both of the better-known alternatives. DART relied on pure momentum transfer from a high-speed impact. A surface nuclear burst, by contrast, offers far more raw energy but loses efficiency if too much of the blast expands away from the asteroid. The crater-burial concept tries to combine the nuclear option’s energy with a geometry that transfers more of it into the target.
The simulations, published in Space: Science & Technology, examined asteroids from 50 meters to 1 kilometer across. The reported results were dramatic. A 50-meter asteroid could be completely broken up by a 300-kiloton device, while a 100-meter asteroid could be shattered by a three-megaton device. For a 1-kilometer asteroid, the study said a three-megaton explosion placed below the surface could change the object’s speed enough to alter its path over long distances.
Burial depth was a major lever. For the 1-kilometer case, the reported speed change was about 0.2 miles per hour when the device was placed 5 meters beneath the surface, and more than 0.67 miles per hour at 20 meters. That trend is the real takeaway from the modeling: the deeper placement did not just add power on paper, it materially increased how much push the asteroid received.
That also helps explain why the researchers cast the approach as potentially more useful than a direct high-speed nuclear impact. If a warhead has to survive an impact around 20 kilometers per second, the design problem gets much harder. The two-stage concept separates excavation from detonation, letting mission planners choose where the explosion occurs instead of accepting a largely fixed impact geometry and extremely tight timing.
Against NASA’s DART mission, the scale difference is easy to see even though the methods are not directly equivalent. DART struck the 160-meter asteroid Dimorphos and changed its speed by 2.7 millimeters per second, a real-world result that planetary defense agencies are still studying through follow-on work such as ESA’s Hera mission. The new study’s argument is that a buried detonation could generate a much larger velocity change, which in turn could cut the warning time needed for a successful deflection.
The warning-time issue is what gives this concept public value beyond the headline-grabbing numbers. The researchers argued that stronger velocity changes could make intervention possible with far less lead time than a kinetic impact mission. That does not mean kinetic impact is obsolete. It means the two approaches serve different parts of the threat envelope: DART demonstrated a lower-energy, non-nuclear deflection method, while the crater-burial concept is being positioned as a higher-energy option for larger objects or late detections.
There are still major boundaries around the result. This was a simulation study, not a flight test, and no known large asteroid is currently on a collision course with Earth. Europe’s Near-Earth Object risk list tracks objects with non-zero impact probabilities, but planetary defense remains mostly a detection and preparedness problem, not an active emergency. The researchers themselves framed the work as a theoretical foundation for mission planning and engineering design, not as a near-term operational system.
That distinction matters because the harder part is not only physics. A real mission would have to integrate tracking, intercept timing, autonomous guidance, crater creation, placement accuracy, and international policy constraints around nuclear devices in space. Even so, the study sharpens a real engineering point: if Earth ever faces a short-warning asteroid threat, where the energy is delivered may matter as much as how much energy is available.
For now, DART remains the only asteroid-deflection method proven in space. But these simulations make a clear case for why future defense planning may not stop at hitting a space rock head-on, especially if the clock is running faster than a simple impact can handle.
By David Whitaker — Associate editor for AMI’s aerospace and drone systems desk, translating flight systems, aircraft programs, spaceflight, and UAV developments into accessible technical stories.
