Imagine looking up at the night sky and knowing that somewhere among the thousands of satellites orbiting Earth, one might be hiding a nuclear weapon. For most of us, that's an invisible threat. But one MIT professor is working to change that.
Areg Danagoulian, a professor at the Massachusetts Institute of Technology, has designed a small satellite sensor that could spot hidden nuclear weapons in space with 99% accuracy. His work, published in the scientific journal Nature, addresses a startling gap in international security: while a 1967 treaty bans nuclear weapons in space, nobody has figured out how to actually check if countries are following the rules.
"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," Danagoulian said.
The urgency behind his research is real. In 2022, Russia launched a satellite called Cosmos-2543 into a strange orbit that passes through one of the most radiation-heavy zones around Earth. Russia says it is for surveillance, but U.S. officials believe it may carry parts of a nuclear device. Danagoulian notes that putting a satellite in such a hostile environment makes little sense for ordinary purposes, but it would make sense if someone wanted to trigger a nuclear explosion that could trap deadly electrons around Earth and destroy many of the satellites we rely on for GPS, internet, and phone networks.
Danagoulian's sensor works by detecting neutrons produced when high-energy particles hit radioactive material. He calculates that a sensor about the size of a large encyclopedia could identify a nuclear weapon if it orbited within 4,000 meters of a suspicious satellite for roughly one week. That detection time could shrink to just a few hours if multiple sensors worked together or got as close as 1,000 meters.
The new technology could also help prevent a repeat of what happened in 1962, when the U.S. detonated a 1.4-megaton nuclear warhead in space as a test. The blast freed so many electrons that they became trapped in Earth's radiation belts and damaged satellites for months. A nuclear detonation in space today could knock out thousands of satellites, disrupting life on Earth in ways most people never think about.
Danagoulian says his immediate goal is to get national research labs and policymakers to take the technology seriously and develop it further. The 1967 Outer Space Treaty has been signed by 118 countries, including the U.S., China, and Russia, but it has always lacked a way to enforce its most important rule. Danagoulian hopes his sensor could change that.
"I very much hope this will turn into a real system, or proof-of-concept system," he said. "The goal right now is to get national labs to use this work for their own research, and to get policymakers to seriously consider this technology as a potential part of national technical means."
In other words, the next time a suspicious satellite launches into an unusual orbit, there might finally be a way to find out what it really contains.