A military satellite is an artificial satellite used for a military purpose. The most common missions are intelligence gathering, navigation and military communications.
The first military satellites were photographic reconnaissance missions. Some attempts were made to develop satellite based weapons but this work was halted in 1967 following the ratification of international treaties banning the deployment of weapons of mass destruction in orbit.
The militarisation of space involved the placement and development of weaponry and military technology in outer space. The early exploration of space in the mid-20th century had, in part, a military motivation, as the United States and the Soviet Union used it as an opportunity to demonstrate ballistic-missile technology and other technologies having the potential for military application. Outer space has since been used as an operating location for military spacecraft such as imaging and communications satellites, and some ballistic missiles pass through outer space during their flight. As of 2018, known deployments of weapons stationed in space include only the Almaz space-station armament and pistols such as the TP-82 Cosmonaut survival pistol (for post-landing, pre-recovery use).
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 including 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" for the US' use of these capabilities. The use of Starlink satellites by Ukraine has played a major role in the Russian-Ukrainian War.
Plesetsk Cosmodrome (Russian: Космодром «Плесецк», romanized: Kosmodrom "Plesetsk") is a Russian spaceport located in Mirny, Arkhangelsk Oblast, near the town of Plesetsk, from which it takes its name. Until 2025 and the commissioning of the Andøya base in Norway, it was the only operational orbital spaceport in Europe and the northernmost spaceport in the world. Originally developed as an intercontinental ballistic missile (ICBM) site for the R-7 missile, its strategic location approximately 800 kilometres (500 mi) north of Moscow was key to its selection.
Due to its high latitude, Plesetsk is particularly suited for specific types of satellite launches, such as those into Molniya orbits, and historically served as a secondary launch facility. Most Soviet orbital launches were conducted from Baikonur Cosmodrome, located in the Kazakh SSR. However, following the dissolution of the Soviet Union, Baikonur became part of Kazakhstan, which began charging Russia to lease the land for its use. As a result, Plesetsk has seen significantly increased activity since the 2000s, especially for launching military satellites.