The independent resource on global security

Russia’s anti-satellite test should lead to a multilateral ban

Russia’s anti-satellite test should lead to a multilateral ban
Space debris in orbit around planet earth. Photo: Adobe Stock
Nivedita Raju

On 15 November, Russia conducted a direct-ascent anti-satellite (DA-ASAT) test, destroying one of its own space objects, a defunct satellite, in low-earth orbit. The test captured international attention and was quickly and widely condemned as threatening and irresponsible—not least for the cloud of lethal, uncontrollable debris it created, which will endanger both space assets and human spaceflight for years to come.

The drivers behind Russia’s test remain unclear and official statements do not reveal what prompted it. However, the test and the international response to it have arguably improved the prospects for an urgently needed, outright international ban on debris-creating ASAT tests.

The test and its consequences

The test involved the PL-19 Nudol system, an anti-ballistic missile interceptor that can also be used as a direct-ascent anti-satellite weapon (meaning that it is launched from the ground rather than space). This was the latest of several Russian tests of the Nudol system, but was the first involving destruction of a target in orbit. That target was Cosmos-1408, a satellite with an approximate mass of 2200 kilograms that had previously been part of the Soviet Tselina-D electronic intelligence system. Notably, the test was conducted in low-earth orbit at an altitude of 480 km, the environment used for numerous space activities.

The Russian test clearly illustrates the risks associated with ‘destructive’ ASAT tests (i.e. those that seek to destroy the satellite rather than disable it with non-kinetic means such as lasers or electronic interference). Smaller pieces of space debris, even a millimetre in diameter, can inflict severe damage on satellites and other space assets. The United States Space Command estimated that the 15 November test created over 1500 pieces of trackable debris (10 cm in diameter or larger) and is likely to generate hundreds of thousands of smaller pieces. LeoLabs, an independent space start-up, has been monitoring the debris from the test and by 19 November had identified 250–300 larger fragments.

The debris field is likely to keep growing and, given the altitude of the test, perhaps migrate and disrupt activities occurring in higher orbits.

Responses from states and private actors

The test drew strong condemnation from the international community. Within hours, the US Space Command had published its assessment of the hazards created by the test and accused Russia of ‘a deliberate disregard for the security, safety, stability, and long-term sustainability of the space domain for all nations’. The US State Department said the test threatened the long-term future of international collaboration in space and was something that ‘the US will not tolerate’.

Others to object in the wake of the test included Australia, the European Union, France, Germany, JapanNATO and South Korea. China and India—the two countries other than Russia and the USA that have previously conducted destructive ASAT tests—are yet to comment publicly.

Several private actors in the space sector have also spoken out emphatically against the test, including Astroscale, Virgin Orbit, the Satellite Industry Association and the Space Data Association.

It is worth noting that India’s destructive ASAT test in March 2019 generated fewer and much softer responses than Russia’s.

The risks associated with space debris

All destructive ASAT tests create debris. Space debris can multiply when the fragments collide with each other, a phenomenon known as the Kessler syndrome. Even ASAT tests that seek to minimize the amount of debris—such as India’s, which was conducted at a lower altitude of approximately 285 km—create debris that remains in orbit for months. Debris at higher altitudes can take years, even decades, to deorbit, after which it burns up in the atmosphere while falling back to earth.

The 480 km altitude of the Russian test is particularly worrying as a number of space activities take place debris in this orbit. The debris created from this test now endangers the civilian and military activities of both states and private actors, including the military space assets of Russia and its allies.

Shortly after the Russian test, the crew of the International Space Station (ISS), including several Russians, was forced to take emergency measures and shelter in their spacecraft due to the risk of collision with an approaching debris cloud.

While Russia disputes that any threat was created by the test, the ISS emergency manoeuvre underlined the potential consequences of destructive ASAT testing. NASA reported in May this year that the ISS had conducted 29 debris-avoidance manoeuvres since 1999. This included an incident as recent as 2020, when the ISS was at risk of collision with debris from a Chinese ASAT test that took place 13 years earlier.

The current regulatory framework

The Russian test and the reactions to it present a window of opportunity to tighten the regulation of ASAT tests and ban debris-creating tests outright. A statement by the Russian Foreign Ministry after the test claimed that it was carried out in ‘strict conformity with international law, including the 1967 Outer Space Treaty’. This is questionable.

The Outer Space Treaty is the primary legally binding international agreement regulating activities in space. Its Article IX lays down a number of obligations for states. It requires that states be guided by the principle of cooperation and mutual assistance. Furthermore, it explicitly requires that states ‘pursue studies of outer space, including the Moon and other celestial bodies, and conduct exploration of them so as to avoid their harmful contamination’ and ‘where necessary . . . adopt appropriate measures for this purpose’.

The article additionally obliges states to conduct their space activities with ‘due regard to the corresponding interests of all other States Parties to the Treaty’. As noted, every destructive ASAT test creates new debris that impacts the outer space environment and magnifies the risk of collision for all space activities. The Russian test violated all these obligations.

Article IX also states: ‘If a State Party to the Treaty has reason to believe that an activity or experiment planned by it or its nationals in outer space . . . would cause potentially harmful interference with activities of other States Parties in the peaceful exploration and use of outer space . . . it shall undertake appropriate international consultations before proceeding with any such activity or experiment.’ It seems clear that the test violated Article IX on this basis as well: first, as the creation of debris has certainly affected the interests of other states, and second, as Russia failed to consult with others in advance of the test.

The enforcement of Article IX is, however, weakened by its reliance on subjective judgements. This is evident from the fact that the Russian Foreign Ministry maintained in its statement that the test ‘. . . does not pose any obstacles or difficulties to the functioning of orbital stations and spacecraft, or to other space activities’. It is implausible that a test with these parameters would not create such ‘obstacles or difficulties’. This statement—coupled with the decision to conduct the test, along with the precedent of tests conducted by China, India and the USA in the past 15 years—sadly suggests that destructive ASAT tests are becoming normalized despite Article IX. For the sake of international security and for the future of all space activities, this should not be allowed to happen. Condemnation of Russia’s test therefore needs to be followed by discussions on how to discourage future debris-creating ASAT tests.

Challenges to space security

Despite the long-term hazards they create and their potential to drive arms-racing behaviour, the current legal framework does not prohibit states from carrying out debris-creating ASAT tests.

The dual-purpose nature of the weapon systems concerned—for both missile defence and ASAT purposes—poses a challenge to future regulation because states such as the USA are reluctant to limit these capabilities. Progress on regulating space security has additionally been hampered by issues of form rather than substance. Western states tend to prefer voluntary ‘soft law’ instruments, while others—including China and Russia—want only legally binding treaties.

Attempts to introduce additional regulation include a 2008 proposal by the European Union for a code of conduct. The draft code was revised and rebranded as the International Code of Conduct for Outer Space Activities in 2014. However, several states criticized the content and the process. Consequently, negotiations towards its adoption broke down in 2015. In 2018 the United Nations Institute for Disarmament Research proposed a set of guidelines for ASAT testing.

Both of these proposed instruments are voluntary in nature. In contrast, China and Russia have long sought support for a draft treaty on the prevention of the placement of weapons in outer space and of the threat or use of force against outer space objects (PPWT). In Russia’s statement on the 15 November test, it suggested the PPWT as a basis for future work on a binding treaty.

In an attempt to overcome states’ differing approaches at the multilateral level, in December 2020, the United Kingdom led an initiative resulting in a new UN General Assembly resolution on reducing space threats through norms, rules and principles of responsible behaviour (rather than limiting hardware and capabilities). Among its provisions, the resolution invited states to ‘share their ideas on the further development and implementation of norms, rules and principles of responsible behaviours and on the reduction of the risks of misunderstanding and miscalculations with respect to outer space,’ and does not rule out the possibility of a legally binding treaty.

Both states and non-state actors were invited to submit comments on the issues raised in the resolution. Their submissions demonstrate that many share concerns about kinetic ASAT tests (i.e. those tests that involve motion-based physical destruction of a target satellite). Other stakeholders that did not expressly mention kinetic ASAT tests did mention the growing hazards of space debris.

The UN General Assembly First Committee has recommended convening an open-ended working group in 2022 to continue discussions. While the resolution is seemingly only a small step forward, it has the potential to spur meaningful space security measures and break the ongoing space security stalemate.   

A ban on destructive ASAT tests is needed

The idea of tighter regulation of ASAT tests and, in particular, a ban on destructive ASAT tests seems to have gained considerable momentum.

Many statements condemning Russia’s 15 November test included calls for action. Several expressly mentioned the need to develop norms, principles and rules for responsible behaviour in outer space through ongoing multilateral processes. The Secure World Foundation (an American non-governmental organization) issued a statement specifically urging states that have publicly demonstrated DA-ASAT capabilities to adopt unilateral moratoriums on testing.

Two months before the test, the Outer Space Institute (a Canadian think tank) published an open letter urging the UN General Assembly to consider introducing a treaty-based ban on kinetic ASAT testing.

Treaty-based bans on weapon tests have been successfully adopted in the past, for example the 1963 Partial Test-Ban Treaty banning nuclear weapon tests in space and the Outer Space Treaty’s prohibition of any weapon tests on the moon or other celestial bodies.

These proposals recentre the urgency of regulating destructive ASAT tests among the broader discussions on space security. A ban on such ASAT tests is essential. This is not only to prevent the unnecessary creation of space debris, but also to slow the rapid pace at which we are moving towards an arms race in space, and the resulting potential for conflict involving the outer space environment. A ban would curtail ASAT testing by focusing on behaviour, rather than limiting the technology itself—an approach more palatable to states that have been averse to new regulation due to fear of constraints on missile defence.  

Further boosting the prospects of a ban becoming reality, last week the US Department of Defense stated publicly that a prohibition on debris-creating ASAT tests was a priority. Russia has also indicated its willingness to work on space security issues with all states, including the USA, which suggests that there is scope to pursue multilateral solutions.

Russia’s ASAT test has sounded alarm bells. Policymakers around the world should heed them to accelerate discussions and pursue a multilateral ban on destructive ASAT tests.


Nivedita Raju is a Researcher in the SIPRI Armament and Disarmament research area.