Oxuz Sentinel

Detecting undeclared nuclear weapons in orbit

The Outer Space Treaty bans nuclear weapons in orbit, but until recently there was no public way to verify compliance. Sentinel scans the active-satellite catalogue for objects transiting the inner Van Allen belt, the region where naturally trapped protons induce detectable spallation neutrons off a weapon’s uranium, and reads out how quickly an inspector could confirm one, using only public data and openly published physics.