Scientists propose satellite method to detect orbital nuclear weapons

A nuclear physicist has proposed using a shoebox-sized satellite to identify nuclear weapons aboard other spacecraft in orbit. The method would rely on detectors that measure neutrons generated when high-energy protons interact with uranium in a suspected weapon.

Since 1967, the Outer Space Treaty has prohibited nuclear weapons in space. The treaty has been ratified by 118 countries, including Russia and the United States. No verification method has existed until now.

Detection approach The proposed inspector satellite would maneuver near a target spacecraft. Detectors would record neutrons produced by proton-uranium interactions while additional sensors filter out signals from protons and electrons. Simulations indicate the system could identify a thermonuclear weapon at a distance of 4 kilometers after about one week of observation.

Closer approaches or multiple inspector satellites could shorten the required time to hours. The inner Van Allen belt would serve as both a potential detonation site and a source of the high-energy protons needed for detection.

Technical and operational considerations An astrodynamicist noted that the inspector satellite would need to operate very close to its target. Past approaches within tens of kilometers have drawn objections from satellite operators. Without coordination, such proximity could increase collision risk.

The method would function most effectively within a formal treaty verification framework that allows coordinated maneuvers between operators. Russia has denied U.S. allegations that its Cosmos 2553 satellite, launched in February 2022, serves as a test for a space-based nuclear weapon.