Space Domain Awareness & Control

The joint American and Canadian air defence command built out a network of radars and telescopes to track objects in orbit, laying the foundation for what later became dedicated military space situational awareness and space domain awareness missions.

Under the WS-199A programme, Martin's Bold Orion air-launched ballistic missile flew twelve tests between 26 May 1958 and 13 October 1959 before being adapted with an Altair upper stage for the anti-satellite role. Its single ASAT flight passed within 6.4 km of Explorer 6 at 251 km altitude — close enough for a nuclear warhead but not a conventional one.

On 22 September 1959 the High Virgo air-launched missile, carried by a B-58 Hustler, attempted an intercept of Explorer 5, but communications were lost and the camera packs were never recovered. Work on the WS-199 projects ended with the start of the GAM-87 Skybolt project.

Following an April 1960 meeting at which Vladimir Chelomei secured a go-ahead for the UR-200 rocket as an ASAT launcher, the decision to begin work on the Istrebitel Sputnikov ('destroyer of satellites') weapon was taken in March 1961. The system was co-orbital, manoeuvring near its target over one to two orbits before detonating a shrapnel warhead. This established the first sustained state programme dedicated to destroying satellites.

An adapted nuclear-armed Nike Zeus, codenamed Mudflap and designated DM-15S, served as a US ASAT from 1962, with a single missile deployed at Kwajalein until 1966. It was superseded by the USAF Thor-based Program 437, which stationed modified Thor missiles armed with nuclear warheads on Johnston Atoll in the Pacific, intended to destroy satellites by radiation and blast effects at a distance; it remained operational until 6 March 1975, by which time the approach had fallen out of favour.

During the 1958 Hardtack Teak test observers noted damaging EMP effects on electronics, and the 1962 Starfish Prime detonation of a 1.4-megaton warhead over the Pacific damaged three satellites and disrupted power and communications. This established nuclear detonation as a crude but effective indiscriminate counterspace method.

Delays in the UR-200 forced Chelomei to use R-7 rockets for prototype testing; Polyot 1 and 2 launched on 1 November 1963 and 12 April 1964, carrying out an intercept test in early 1964. These were the first flight demonstrations of Soviet co-orbital interception hardware.

LLNL developed a proposal in 1968 for an X-ray laser pumped by a nuclear explosion, alongside conventional laser and maser concepts including satellites with fixed lasers and deployable targeting mirrors. The X-ray laser effort was cancelled in 1977 but revived in the 1980s under the Strategic Defense Initiative.

The Soviet Istrebitel Sputnikov programme manoeuvred an interceptor spacecraft close to a target satellite before detonating a warhead, an approach distinct from the direct-ascent missiles other countries later favoured, and one of the earliest dedicated anti-satellite systems. After initial IS test launches on 27 October 1967 and 28 April 1968, in November 1968 the interceptor Kosmos 252 closed within the five-kilometre kill radius of the target Kosmos 248 and detonated its warhead, destroying it — the first successful orbital ASAT intercept, proving co-orbital satellite killing in practice.

After some 23 identified test launches, the Istrebitel Sputnikov system was declared operational in February 1973. It gave the USSR the world's first fielded operational anti-satellite capability.

Elements of the Soviet space industry convinced Brezhnev that the Shuttle was a single-orbit first-strike bomber launched from Vandenberg, prompting renewed IS testing from 1976 and a Soviet shuttle programme. The IS was subsequently expanded to attack higher altitudes and declared operational in that configuration on 1 July 1979.

In the early 1980s the USSR began a counterpart to the US air-launched ASAT, using at least six modified MiG-31D 'Foxhound' aircraft carrying the 79M6 missile. The USSR also experimented with arming Almaz stations with R-23 auto-cannons.

ASATs were low priority in the US until 1982, when knowledge of the successful Soviet programme became widespread in the west. The resulting crash programme produced the Vought ASM-135, based on the AGM-69 SRAM with an Altair upper stage and carried by a modified F-15 Eagle.

Proposed in 1983 by the Reagan administration, the Strategic Defense Initiative — quickly nicknamed Star Wars — envisaged a space-based missile defence system, pushing the militarisation of space to the centre of superpower competition and shaping defence research spending for a decade even though it was never built as envisioned. Though focused on defence against nuclear warheads, it gave both US and Soviet ASAT programmes a major boost, with ASAT projects adapted for anti-ballistic missile use and vice versa. By 1988 the US plan had become a four-stage programme beginning with the Brilliant Pebbles constellation of 4,600 kinetic interceptors in low Earth orbit, at a first-stage cost of about $125 billion by 2000.

In 1983 Andropov terminated IS testing and all later attempts to resume it failed. Ironically the United States began its own ASAT testing at roughly the same time in response to the Soviet programme.

After a first missile launch in January 1984, an F-15 flying from Edwards AFB climbed to 11,613 m and vertically launched an ASM-135 that destroyed the ageing American satellite Solwind P78-1 at 555 km altitude on 13 September 1985. It was the only successful interception of the programme, which was cancelled in 1988, and the only US destructive test of its kind, after which Washington observed an informal moratorium on destructive anti-satellite testing for more than two decades; the last catalogued debris deorbited in May 2004.

The 11F19DM Skif-DM/Polyus, an orbital megawatt laser platform, failed at launch in 1987. It represented the Soviet Union's closest approach to experimental deployment of orbital directed-energy anti-satellite weaponry.

During a 1987 visit to Baikonur Cosmodrome Gorbachev was presented with the 'Naryad' (Sentry) anti-satellite system, also designated 14F11, to be launched by UR-100N rockets. It indicated continuing Soviet work on orbital interception after the end of IS testing.

Both superpowers began reducing expenditure on space weapon research from 1989, and the Russian Federation unilaterally discontinued all SDI research in 1992. Research was later reported to have resumed under Vladimir Putin as a counter to renewed US strategic defence efforts after the Anti-Ballistic Missile Treaty lapsed.

On 11 January 2007 China destroyed its defunct Fengyun-1C weather satellite at about 865 km altitude in a head-on kinetic collision, the SC-19 missile launched from a mobile transporter-erector-launcher at Xichang. The test created more than 40,000 debris fragments larger than one centimetre — the largest orbital debris field on record at the time — prompting international criticism and accelerating other countries' interest in both offensive counterspace weapons and debris-tracking capability. It marked China's entry into the ASAT club; evidence suggests the same SC-19 system was also tested in 2005, 2006, 2010 and 2013.

On 21 February 2008 a ship-fired RIM-161 Standard Missile 3 destroyed the decaying reconnaissance satellite USA-193 about 247 km above the Pacific, officially to disperse its 450 kg of toxic hydrazine. The test produced 174 catalogued debris pieces, the last of which re-entered on 28 October 2009, and demonstrated that sea-based missile defence interceptors could serve as ASATs.

Senior officers said publicly that the service was developing capabilities to disrupt or disable adversary satellites, a shift from earlier public emphasis on defensive space operations, citing growing Chinese and Russian counterspace threats as the rationale.

Armed forces in several countries increasingly bought tracking data and analysis from private space-situational-awareness providers rather than relying solely on government radar and telescope networks, a shift driven by the growing number of satellites and debris objects to monitor.

The French military space programme continued developing small satellites intended to escort high-value French spacecraft and identify close approaches by other countries' inspector satellites, building on an earlier in-orbit demonstration mission.

Japan's Air Self-Defense Force continued expanding a dedicated space unit and a deep-space radar intended to track objects in geostationary orbit, part of a wider effort to monitor threats to Japanese and allied satellites.

India continued building out a dedicated military space organisation formed in the years after its 2019 anti-satellite missile test, part of a broader push to develop space situational awareness and counterspace capability alongside China and Pakistan.

Alliance members worked through how an attack on a member state's satellite might trigger collective defence obligations, while a space centre supporting the alliance continued sharing data among member states on threats to satellites in orbit.

The Shijian-25 satellite approached and conducted close-proximity operations with the older Shijian-21 spacecraft in geostationary orbit, demonstrating refuelling and servicing technology that analysts said could equally be used to disable or move another country's satellite.

US and allied intelligence assessments continued to describe Russian work on a nuclear-armed anti-satellite system intended to disable large numbers of satellites at once through radiation effects rather than striking a single target, a capability that would breach the Outer Space Treaty if fielded.

In 2024 US intelligence sources indicated Russia was developing an anti-satellite weapon involving nuclear technology, though it was unclear whether this meant a nuclear warhead or a nuclear-powered device. The disclosure raised the prospect of a return to indiscriminate nuclear counterspace effects.

Seoul reported repeated episodes of satellite navigation interference originating from North Korean territory, disrupting civilian aviation and fishing vessels near the border, part of a long-running pattern of electronic interference rather than a new escalation.

Delegates renewed calls for a binding ban on weapons in space after Russia had vetoed a similar United Nations Security Council resolution earlier in the year, reflecting a wider stalemate in arms control efforts covering outer space.

In November 2023 Israel's Arrow 3 system intercepted a Houthi-launched missile above the atmosphere, the first exoatmospheric interception during wartime. Experts including Israel Space Agency chairman Yitzhak Ben Yisrael consider the exoatmospheric Arrow 3 capable of operating as an ASAT.

The United States ceased testing of direct-ascent anti-satellite missiles, banning the practice in 2022. The move sought to establish a norm against debris-generating counterspace demonstrations.

In November 2021 a Russian direct-ascent anti-satellite missile destroyed the defunct satellite Kosmos 1408, creating over 1,500 pieces of trackable debris that forced astronauts on the International Space Station to shelter temporarily. The test drew international condemnation over the resulting orbital hazard and intensified concern about debris-generating destructive ASAT demonstrations.

On 27 March 2019 a DRDO interceptor launched from the Integrated Test Range at Chandipur struck the Microsat-R satellite at 300 km altitude after 168 seconds. India stated the low altitude was chosen so debris would decay within weeks; US Air Force Space Command tracked 270 pieces. The test made India the fourth nation with demonstrated anti-satellite missile capability.

Carved out of the Air Force, the new service consolidated American military space operations under a single branch for the first time, reflecting a judgement that space had become a warfighting domain requiring dedicated forces and doctrine.

On 5 February 2018 China tested the Dong Neng-3 exoatmospheric ballistic missile, which has potential ASAT application. State media described the test as purely defensive and said it achieved its objectives.

Launches were reported in December 2016, on 26 March 2018 and 23 December 2018, the latter two from transporter-erector-launchers. US officials said Russia conducted a direct-ascent anti-satellite missile test capable of destroying spacecraft in low Earth orbit on 15 April 2020, with a further test on 16 December 2020.

In May 2013 China announced a suborbital rocket carrying an ionospheric science payload, but US government sources described it as the first test of a new ground-based ASAT system. Open-source analysis by the Secure World Foundation, using commercial imagery, concluded it may have been an ASAT test threatening satellites in geostationary orbit.

On 10 February 2010, DRDO Director-General V. K. Saraswat said India possessed all the necessary building blocks to integrate an anti-satellite weapon against targets in low Earth and polar orbits, following an earlier announcement at the 97th Indian Science Congress. In April 2012 he confirmed the critical technologies came from radars and interceptors of the Indian Ballistic Missile Defence Programme, and the ASAT programme was formally sanctioned in 2017.

In August 2009 Alexander Zelin announced that the Russian Air Force had resumed the MiG-31D project, shelved after the Soviet collapse due to reduced defence spending. The Sokol Eshelon airborne laser prototype on an A-60 aircraft was reported restarting development in 2012, and a new ASAT missile was seen on a MiG-31 in September 2018.