How many countries have nuclear weapons and how many are there? How destructive are today’s nuclear weapons? What about “nuclear deterrence” theory? Do nuclear weapons help keep the peace? What is the New START Agreement and why has Russia suspended its implementation? What is the Treaty on the Prohibition of Nuclear Weapons? Why does this treaty matter if none of the countries with nuclear weapons have joined? Why should one country give up its nuclear weapons if other countries still have them? Why should countries that don’t have nuclear weapons care about this treaty? Can a NATO state join the TPNW? Did Ukraine give up nuclear weapons? What are "tactical" nuclear weapons? What are 'dirty bombs'? What is the nuclear test ban treaty and why has Russia revoked its ratification? What are space nuclear weapons?

What are space nuclear weapons?

Answer

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.