In 2024, a U.S. government official warned that Russia could be developing a new satellite designed to carry nuclear weapons into space. This statement followed the launch of a suspicious Russian satellite into low-Earth orbit in 2022, just weeks before the full-scale invasion of Ukraine. A nuclear detonation in low-Earth orbit—approximately 100 to 1,200 miles above Earth—would release trillions of highly energetic electrons, destroying many satellites and disrupting telecommunications networks, GPS, space-based internet, and more. Although the 1967 Outer Space Treaty bans the placement of nuclear weapons in space, there is currently no method to verify whether satellites contain nuclear weapons. In fact, no verification methods have been proposed in unclassified, peer-reviewed literature.
Now, MIT Professor Areg Danagoulian proposes a way to determine if a satellite orbiting Earth contains a nuclear weapon. In a new paper published in Nature, Danagoulian describes a satellite-based sensor system that could orbit close to a suspect satellite and detect neutrons generated by high-energy protons colliding with radioactive material. He calculates that a sensor system the size of a large encyclopedia could detect a nuclear weapon with 99 percent accuracy if it orbited within 4,000 meters of the suspect satellite for about a week. He estimates that detection time could be reduced to hours if multiple satellite sensors were used or the sensor satellite got within 1,000 meters of the suspect satellite.
Danagoulian states, "If we eventually have some verification mechanisms for the Outer Space Treaty, that will put pressure on countries to respect the treaty or disclose what they are doing, because they know if they try to violate it, we will find out."
In 1962, the U.S. detonated a 1.4-megaton thermonuclear warhead in space, unintentionally destroying many early satellites. The blast released enormous volumes of highly energized electrons that became trapped in Earth's magnetic field, damaging electronics in their path. Danagoulian explains, "When you have a nuclear detonation in outer space, basically the whole body of the bomb becomes ionized, and nearly every single electron in the weapon’s mass becomes free."
The approach Danagoulian developed centers on a reaction known as spallation, caused by highly energetic protons in radioactive environments. He explains, "When an energetic proton slams into elements with a high atomic number, like uranium and plutonium, each proton may knock out something like 40 neutrons." He believes the system, placed inside an inspector satellite, would survive the harsh environment of low-Earth orbit and be fast enough to process the protons, electrons, and neutrons that bombard it.
Danagoulian's calculations indicate that if a detector satellite could get within 1,000 meters of the suspect satellite, it could accurately detect nuclear weapons in about one hour, requiring just a single flyby. He calls the paper a feasibility study of the concept, aimed at showing the scientific community that scientifically proving the presence of a nuclear weapon in space is possible. He hopes the study will stimulate further research and development.
Blogger's Review: Danagoulian's research offers a fresh perspective on monitoring nuclear weapons in space, which is increasingly crucial in today's international security landscape. The potential for effective satellite monitoring could significantly enhance transparency regarding nuclear threats, possibly fostering a new foundation of trust in international relations through the enforcement of the Outer Space Treaty.