MIT professor develops method to verify compliance with Outer Space Treaty

No verification and no trust: Since 1967, a total of 117 countries have signed the Outer Space Treaty, including the three countries with the most nuclear weapons: Russia, the United States, and China. However, as Danagoulian states in his paper, "No methodologies of verification have been proposed in the open peer-reviewed literature."

Moreover, U.S. officials have alleged that Russia has a program to develop a nuclear anti-satellite weapon for deployment in Earth orbit. In the current conflict-plagued global geopolitical environment, other nations likely hold similar concerns. If nations had a way of verifying other nations' compliance with the Outer Space Treaty, it would help allay such worries.

Spallation: Danagoulian developed a concept for a satellite-based sensor system that would use spallation (the release of particles due to high-energy collisions) to detect if a nearby satellite is carrying a nuclear weapon. The detector, or inspector, satellite would emit highly energetic protons that, if colliding with a radioactive element like uranium or plutonium in a nuclear weapon, would cause the release of large numbers of neutrons into space. Scintillators on the inspector satellite would be able to detect the released neutrons, which would serve as evidence of a nuclear weapon.

According to Danagoulian's calculations, an inspector satellite equipped with such a spallation system would be able to accurately detect the presence of a nuclear weapon within one hour by flying by a suspect satellite within a distance of 1,000 meters. Given an observation distance of 4,000 meters, the inspector satellite would be able to identify a nuclear weapon with 99 percent accuracy within about a week. The use of multiple inspection satellites would reduce that time.

Danagoulian hopes his study "will stimulate and inform future research and development of verification platforms for the OST," he said in his paper. In an article in MIT News, he explained, "I say in the paper this isn't a completely proven system. The purpose of the paper is to show the scientific community that it's scientifically possible to do this. But there are many more practical considerations to be made to actually build these detectors."

Better than intelligence: If such detectors are built, Danagoulian believes they will prove far more accurate than conventional intelligence-gathering methods that have been used in nonproliferation efforts. As he told MIT News, "You can fake intelligence, but you can't fake physics."

He emphasized, "I very much hope this will turn into a real system, or proof-of-concept system, but 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."