What are space nuclear weapons?


The capability to deploy nuclear weapons into space is explicitly prohibited in the 1967 Outer Space Treaty. Detonating a nuclear weapon in space would create an electromagnetic pulse that would damage satellites indiscriminately, unless they are specially hardened, and create a tremendous amount of debris which could cause additional damages. The effect of a nuclear explosion in space on spacecraft was demonstrated in 1962 by the U.S. Starfish Prime test and led to the 1963 Limited Nuclear Test Ban Treaty.

Low earth orbit is used by commercial satellites for many purposes - from communications to transportation to weather forecasting. There are a number of disruptive technologies that could impact satellites- from kinetic anti-satellite weapons (ASAT) (which would physically destroy the satellites), to signal jamming spacecraft, which could make existing satellites useless.

Anti satellite weapons (ASAT) tests have been conducted by China, Russia and the United States. In February 2024, there was increased attention on this type of weapon following news reports  that Russia may be developing a nuclear weapon that can be deployed into space. In 2022 the United States pledged not to conduct destructive anti-satellite tests. For more than three decades there have also been discussions in the UN Committee on Peaceful Uses of Outer Space and the Conference on Disarmament.