Areg Danagoulian, a nuclear scientist at the Massachusetts Institute of Technology (MIT), has proposed a satellite-based sensor system to detect hidden nuclear weapons in orbit. Published in the journal Nature, the feasibility study suggests using Earth’s Van Allen radiation belts to trigger neutron emissions from uranium, providing a verification method for the 1967 Outer Space Treaty.
Using the Van Allen Belts as a Particle Beam
The Outer Space Treaty of 1967, signed by 118 countries, prohibits the placement of nuclear weapons in orbit. However, as Gizmodo reports, the agreement lacks a robust verification mechanism. Militaries currently have no practical way to confirm if a satellite is carrying a thermonuclear device.
Danagoulian’s proposal turns a known space hazard into a detection tool. The inner Van Allen radiation belts are swarms of high-energy charged particles trapped by Earth’s magnetic field. When a satellite containing uranium passes through these belts, high-energy protons collide with the radioactive material. This process, known as spallation, knocks neutrons loose from the uranium nuclei.
“When the satellite carrying a thermonuclear weapon passes through the inner Van Allen Radiation belts surrounding Earth, protons in that belt knock out many neutrons from uranium nuclei. By devising a very particular type of neutron detector, one can detect these neutrons – which would be a tell-tale sign of unusual quantities of uranium on a satellite.”
Areg Danagoulian, MIT nuclear scientist, via ScienceAlert
The scale of this emission is significant. Danagoulian estimates a thermonuclear weapon could emit as many as 40 million neutrons per second. While detecting these in the harsh radiation environment of low Earth orbit is an engineering challenge, the physicist asserts that the necessary technologies already exist.
The Russian Kosmos 2553 Controversy
The urgency for such a system is driven by recent orbital activity. In February 2022, Russia launched the Kosmos 2553 satellite. While the Kremlin maintains the craft is part of a radar system, the U.S. has alleged it is designed to help develop a nuclear antisatellite system.
According to Popular Science, Kosmos 2553 follows an unusual orbit that routinely passes through the most radioactive regions above Earth. Danagoulian noted that such a location is likely the best point for trapping electrons if a thermonuclear weapon were detonated. The satellite is believed to be nonoperational after it began to spin out of control in April 2025.
The strategic stakes involve the vulnerability of global communications. Jeffrey Lewis, a distinguished fellow at the Foreign Policy Research Institute, told Scientific American that Russia may be exploring ways to disable U.S. space capabilities. Lewis suggests the Kremlin might calculate that a world where no one has space capabilities is preferable to one where the U.S. maintains a dramatic advantage.
Historical Precedent and the Risk of EMPs
The danger of space-based nuclear detonations is not theoretical. In 1962, the U.S. conducted the Starfish Prime test, detonating a 1.4-megaton warhead 250 miles above the Pacific Ocean. The results were catastrophic for early orbital infrastructure.
- Satellite Damage: Roughly one-third of satellites in low Earth orbit were damaged or destroyed.
- Atmospheric Impact: The blast created an artificial radiation belt by injecting charged electrons into the inner Van Allen belt.
- Terrestrial Effects: An electromagnetic pulse (EMP) damaged an estimated 300 streetlights in Hawaii, nearly 900 miles away.
Today, a similar event would jeopardize the satellites underpinning GPS navigation, weather forecasting, and missile warning systems. Danagoulian explains that a nuclear detonation in space ionizes the bomb’s mass, freeing electrons that merge into the Van Allen belts and bombard other orbiting objects.
The Path to Implementation
Danagoulian’s work is a feasibility study rather than a working prototype. He notes that the project is currently characterized by 100 percent secrecy. The proposed system would involve launching a sensor-equipped satellite to orbit near a suspect spacecraft to monitor for the specific neutron signatures of spallation.
The physics relies on a combination of nuclear physics, orbital mechanics, and space weather. The primary hurdle remains the engineering required to distinguish these neutrons from the general background radiation of space.
You have to get all of those right. It’s a combination of nuclear physics, space weather, and orbital mechanics.
Areg Danagoulian, MIT nuclear scientist, via ScienceAlert
If implemented, this system would shift the Outer Space Treaty from a “gentleman’s agreement” to a verified legal framework. By providing an objective way to detect uranium in orbit, the international community could identify treaty violations without relying solely on diplomatic trust or inconclusive surveillance.
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