Space warfare

Space warfare is combat in which one or more belligerents are in outer space. The scope of space warfare includes ground-to-space warfare, such as attacking satellites from the Earth; space-to-space warfare, such as satellites attacking satellites; and space-to-ground warfare, such as satellites attacking Earth-based targets. The 1967 Outer Space Treaty forms the basis of space law; it prohibits permanent basing of weapons of mass destruction, such as nuclear weapons, in space and the military use of celestial bodies but does not prohibit the military use of Earth orbit or military space forces. Independent space forces are operated by the United States (US Space Force) and China (People's Liberation Army Aerospace Force). Russia operates significant space assets under the Russian Space Forces.

The Cold War prompted the start of the militarization of space. Military satellites have been launched since the late 1950s for communications, navigation, reconnaissance and munitions guidance. The Gulf War is sometimes called the "first space war" because of the use of these capabilities by the US. The use of Starlink satellites by Ukraine has played a major role in the Russian-Ukrainian War.

The US and Soviet Union carried out nine nuclear explosions in space from 1958 to 1962, which damaged satellites. Orbital space weapons were developed, especially for defence against nuclear missiles, but not widely deployed. The US Strategic Defense Initiative studied satellite-mounted advanced weaponry, drawing criticism as the "Star Wars program". The Soviet Union developed Istrebitel Sputnikov co-orbital weapons, Almaz military space stations, and the Polyus laser. Since 2025, the US has been developing the Golden Dome missile defense system, which includes orbital weapons.

Ballistic missiles, which transit the upper atmosphere and sometimes outer space, have been used in combat since Germany's V-2 rocket during World War II. These were used on a large scale in the Iran–Iraq War, Gulf War, Red Sea crisis, and Iran–Israel war. In November 2023, Israel claimed an interception of a Houthi ballistic missile as the first combat in space.

Four nations have tested anti-satellite missiles by destroying a target satellite: the US' ASM-135 in 1985 and SM-3 in 2008, China's SC-19 in 2007, India's PDV Mark II in 2019, and Russia's A-235 in 2021. Israel's Arrow 3 missile may also have an anti-satellite capability.