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date: 18 April 2021

Space Security Lawfree

  • P.J. BlountP.J. BlountSchool of Law, University of Mississippi


The use and exploration of space by humans is historically implicated with international and national security. Space exploration itself was sparked, in part, by the race to develop intercontinental ballistic missiles (ICBM), and the strategic uses of space enable the global projection of force by major military powers. The recognition of space as a strategic domain spurred states to develop the initial laws and policies that govern space activities to reduce the likelihood of conflict. Space security, therefore, is a foundational concept to space law.

Since the beginning of the Space Age, the concept of security has morphed into a multivariate term, and contemporary space security concerns more than just securing states from the dangers of ICBMs. The prevalence of space technologies across society means that security issues connected to the space domain touch on a range of legal regimes. Specifically, space security law involves components of international peace and security, national security, human security, and the security of the space environment itself.


Since the beginning of the space age, security has been the critical, overriding concern at the heart of both international and domestic space law regimes. While these regimes certainly encompass broader interests, such as commercial uses of outer space, they are built on a legal foundation that is largely intended to regularize interactions among space actors to ensure security, safety, and sustainability in the space environment. As a result, space security law has central goals of maintaining peace and providing security as a public good for the benefit of humankind.

The idea of security is a technical and political construct. The law is a tool that is used to articulate that construct as concept and operationalize it as a value. As such, space security law is a network of law and regulation that governs a wide variety of space activities. There are four broad categories that typify the various manifestations of space security law: international peace and security; national security; human security; and security of the space environment. International peace and security, the first, is directly concerned with the international law and norms that have been adopted to decrease the risk of conflict between states. National security, the second category, consists of domestic law that implements, at the national level, the obligations found in the first category, as well as law that promotes other national security goals. Human security, the third category, is the loose set of law and policy directed at the use of space for the protection of human populations, such as disaster response and human rights protection. Finally, the fourth category, security of the space environment, represents the emerging body of law and policy that seeks to protect the space environment through measures that address space debris and harmful contamination. Obviously, these categories overlap, and laws can serve duplicative purposes, but this compartmentalization reveals much about the legal structures that surround core security projects being pursued in and through space.

International Peace and Security

International space law, at its very core, is concerned with the maintenance of international peace and security. The space law regime inherits the concept of international peace and security from the Charter of the United Nations, placing it as the central concern of the entire modern international law system (Charter of the United Nations [UN Charter], 1945, Art. 1, §1). Indeed, the launch of Sputnik in 1957 could easily be considered the first major challenge to the newly emerged international system for a number of reasons. First, the launch itself effectively demonstrated intercontinental ballistic missile (ICBM) technology for the first time. This demonstration globalized the threat of nuclear war by diminishing the time and ability of a state to defend against such an attack (See, for instance, Bush, 1949, pp. 116–117). Second, the launch, for the first time in modern history, opened up new spatial territory subject to conquest by humans. The anti-colonial, anti-imperial orientation of the new international law system had sought to diminish the risk of conflict by hardening state borders against external conquest by deploying a new international geography. The new spatial reality of human access to outer space challenged this notion by introducing new territorial possibilities into this international geography. Third, space technology was not neatly compartmentalized within state borders as previous technologies had been. One of the underlying assumptions of the international legal system, deployed in the wake of World War II, was that states with hardened borders were the best legal and political containers for people and things. Space technology, however, transcended those boundaries and enabled truly transnational and global activities. Specifically, space technology enabled telecommunications and remote sensing capabilities that could not be contained by state borders as conceived in the international legal system.

As a result, the international community swiftly responded to the emerging Space Age by incorporating it into the international legal system with an international space law regime. This article examines space security law through the lens of international peace and security. First, it discusses the concept of peaceful purposes as applied to outer space. Next, it discusses how space security is structured with legal mechanisms in the Outer Space Treaty. Finally, the article considers the legal issues related to the possible weaponization of space.

Peaceful Purposes

Space technology emerged in a security environment inscribed with the Cold War rivalry between the United States and the Soviet Union. When the USSR launched Sputnik, both states had obtained nuclear weapon capabilities, and each saw the other as an existential threat to its own existence. The ideological differences between the two would play out across the global landscape as the two states came into indirect contact through proxy wars. The introduction of ICBM technology, though, threatened to place the two states into direct contact and direct conflict by making a nuclear attack on the other’s territory a possibility (Logsdon, 1998, p. vii). ICBM technology significantly reduced the time it would take to mount a nuclear assault, meaning that the adversary would have less time to defend against it. Temporal reductions of this sort heightened the risk of direct conflict, by giving the state that struck first a decisive advantage. While these states recognized that curtailing ICBM technology, which reduced the time of an attack to hours, may not be possible, there was recognition that orbital weapons, which would reduce the time of attack to minutes thereby eliminating the risk of a counter attack, would present an untenable security situation. As a result, even before Sputnik was launched, both superpowers began framing outer space as a domain to be used for peaceful purposes.

As both the United States and the USSR explored the possibilities of rocket technologies in the early 1950s, each pledged to place an artificial satellite into space during the International Geophysical Year (IGY) that was planned from July 1957 to December 1958 (National Academies; and NASA, International GeoPhysical Year). Connecting these pledges to a global scientific event framed these initial space activities as scientific endeavors, despite the fact that both states were acutely aware of the military advantages to be gained through space technologies (e.g., see National Security Council, 1955). After the launch of Sputnik, this framing continued and began to take on the attributes of a more substantive obligation. The United States led this effort with its National Aeronautics and Space Act of 1958, which declared that the policy of the United States was that its “activities in space should be devoted to peaceful purposes for the benefit of all mankind” (National Aeronautics and Space Act of 1958, § 101[a]). This idea was then taken up by the United Nations General Assembly (UNGA) in its first resolutions on space. In 1958’s Resolution 1348 (XIII): Question of the Peaceful Use of Outer Space, the UNGA declared that “space should be used for peaceful purposes only,” and it established an ad hoc Committee on the Peaceful Uses of Outer Space to report on, among other things, UN facilitation of the peaceful use of outer space and international co-operation on the peaceful uses of outer space (UN General Assembly [UNGA], 1958, Resolution 1348, XIII). The idea of peaceful uses has remained a mainstay of UNGA resolutions since that time, and the UNGA passes an annual resolution on international cooperation in the peaceful uses of outer space (UNGA, 2016, Resolution 71/90). It should be noted, of course, that UNGA resolutions do not make binding law. The point here is to emphasize the long-standing emphasis that UNGA has placed on the idea of space for peaceful purposes.

Interestingly, the term peaceful purposes appears in the Outer Space Treaty only twice. It first appears in the perambulatory text, which declares that there is a “common interest of all mankind in the progress of the exploration and use of outer space for peaceful purposes” (Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies [Outer Space Treaty], 1967, Preamble). The second appearance is in Article IV, which declares that “[t]he Moon and other celestial bodies shall be used by all State Parties to the Treaty exclusively for peaceful purposes” (Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies [Outer Space Treaty], 1967, Art. IV). As a result, it can be said that as a matter of treaty law, peaceful purposes only applies to the Moon and other celestial bodies, as a lesser included part of outer space as a whole, but that the object and purpose of the treaty is to ensure the peaceful uses of outer space as a whole. It should be noted that these are two different regimes. The definition of peaceful purposes applicable to the Moon and other celestial bodies is strictly non-military, whereas as peaceful purposes applicable to space allows some degree of military action.

Despite the fact that the negotiators of the Outer Space Treaty declined to include peaceful purposes as a general legal obligation in space, it is submitted here that the concept has nonetheless entered into the realm of customary international law. The term consistently appears throughout UNGA resolutions, which garner unanimous or near unanimous support for state parties (see generally, UN Office of Outer Space Affairs [UNOOSA], “Documents and Resolutions Database”). Additionally, the UN organ most directly concerned with outer space matters is the United Nations Committee on the Peaceful Uses of Outer Space (UNCOPUOS), which is a consensus driven body (Marchisio, 2005, p. 224). Further, the term consistently appears in state laws and policies pertaining to space, which indicates its widespread acceptance as a legal obligation (Blount, 2009). A salient example of this is North Korea, which sought to justify its space program as being outside the scope of the UN Security Council (UNSC) resolutions that would prohibit it from engaging in ICBM activities, by claiming that the program was for peaceful purposes (Korean Central News Agency, 2012).

States seem to unanimously agree that space is to be used for peaceful purposes, and the implication is that peaceful purposes is more than just a legal obligation; it is the threshold for legality of any space activity. However, there seems to be great ambiguity as to the exact meaning of peaceful purposes, at least in part because it is not a treaty term with definition, except with its applicability to the Moon and other celestial bodies (Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies [Outer Space Treaty], 1967, Art. IV). While the obligation does appear in other areas of international law, it is defined disparately, which indicates that its meaning is specific to its application (see Antarctic Treaty, 1959, Art. 1; Treaty on the Non-Proliferation of Nuclear Weapons [NPT], 1968, Art. III; and United Nations Convention on the Law of the Sea, 1982, Art. 88—high seas, Art 141—deep sea bed). Early in the Space Age, there was debate as to whether peaceful purposes meant simply “non-aggressive,” in line with the regime established by the UN Charter, which bans the aggressive use of force, or whether the term meant “non-military,” a meaning that has been applied in other areas (Antarctic Treaty, 1959, Art. 1; NPT, 1968, Art. III). There has been consistent state use of space for military purposes that are passive or indirect, such as situational awareness monitoring, command and control functions, and intelligence gathering, thus while some developing nations maintain in their diplomatic rhetoric that peaceful purposes means non-military, this interpretation is generally not accepted by space-faring nations. Indeed, Japan in 2008 adopted a new space law that changed its interpretation of peaceful purposes from non-military to non-aggressive (Aoki, 2011, pp. 11–13).

The question, then, remains as to whether peaceful purposes, when applied to space, means more than simply non-aggressive. In other areas of international law, the term is a treaty obligation accompanied by treaty text that articulates the meaning. In space law, one must look to the customary international law surrounding the term. In particular, the UNGA Resolution 1962 (XVIII): Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space can be turned to for particular guidance (1963). This resolution was one of the first attempts by the international community to articulate legal principles that apply to outer space. While not legally binding as such, it was adopted by consensus, and its title indicates that the General Assembly viewed it to have legal significance. Further, the principles articulated in this resolution would later be codified in the Outer Space Treaty, and it is widely considered to be an articulation of the core customary principles that apply to outer space. The preamble to this resolution states that one of its purposes is “to contribute to broad international cooperation in the scientific as well as in the legal aspects of exploration and use of outer space for peaceful purposes,” which indicates that the UNGA is attempting to develop specific principles that apply to the obligation of peaceful purposes (UNGA, 1963). As noted, the principles found in Resolution 1962 (XVIII) were later codified in the Outer Space Treaty and form the core notions underpinning the legal obligation to use space for peaceful purposes. As such, these principles will be addressed in the next section, which discusses security in the treaty regime.

The Space Treaty Regime

At its core, the Outer Space Treaty and the four treaties that followed it are security documents that attempt to limit how states use space in such a way as to maintain stability in international peace and security. The Outer Space Treaty accomplishes this through the use of three general types of mechanisms that were developed to address the security issues that result from space exploration in light of the uncertainty in how the technology would evolve. These mechanisms are external obligations, accountability mechanisms, and socialization mechanisms.

External Obligations

To maintain flexibility, the Outer Space Treaty contains few fully articulated “hard” obligations in the form of specific prohibitions or duties. This is because states were uncertain about what the future of space exploration might hold, and therefore wanted to preserve their right to action as much as possible. The negotiators of the Outer Space Treaty did seek to place some limitation on state action vis-a-vis other states. These are obligations that states must comply with and owe externally to other states in the international community.

The first of these obligations connects the general duty to maintain international peace and security to space and extends the framework of the UN Charter into space. Under Article III of the Outer Space Treaty, international law is extended into space with specific reference to the UN Charter and “international peace and security” (cf. UNGA, 1963, Principle 4). The extension of international law into outer space means that general international law applicable among states will govern their activities in space along with the lex specialis of outer space. It also means that other specialized areas of international law, such as the law of armed conflict, will apply in space when the proper circumstances are present.

As a place in which international law governs, states have deemed space to be non-territorial or a global commons (Blount & Robinson, 2016, pp. 170–171). This idea is found mainly in Article II of the Outer Space Treaty, which states that outer space and celestial bodies “are not subject to national appropriation” (cf. UNGA, 1963, Principle 3). This is further bolstered by the principle, found in Art. I, that states have free access to use and explore space, coupled with the idea that the exploration and use of outer space is “the province of all mankind,” indicating a non-territorial nature for space (cf. UNGA, 1963, Principle 2). By de-territorializing space, the negotiators of the treaty sought to bring space into the international geography, which was deployed by the UN Charter—one of territorial states confined within hard borders, to avoid the types of conflicts that occurred under previous imperial systems of world-scale governance (see Blount & Robison, 2016, pp. 170–172; on the concept of “world-scale governance,” see Sassen, 2006, p. 14). By denying states the ability to gain sovereignty over places in outer space, the negotiators sought to disincentivize states from engaging in conflict over that territory. The non-appropriation principle has consistently been the source of much debate, as its effects on private property rights are unclear, likely because the negotiators of the treaty were more concerned with security issues rather than issues of commercial exploitation (for the diversity in literature on Art. II, see generally Blount & Robison, 2016; Coffey, 2009; de Man, 2015–2016; Ganatra & Modi, 2015–2016; Gangale, 2015–2016; Gorove, 1969; and Masson-Zwaan & Richards, 2015).

The final external obligation is found in Article IV of the Outer Space Treaty. Article IV places specific limitations on weaponization and military action in outer space. Article IV’s first paragraph bans states from placing or stationing nuclear weapons and weapons of mass destruction (WMD) in space or on celestial bodies. In its second paragraph, it states that the “moon and other celestial bodies shall be used . . . exclusively for peaceful purposes.” Unlike the general obligation to use space for peaceful purposes, the regime for the moon and other celestial bodies is strictly nonmilitary and bans the establishment of military infrastructure on these masses, as well as “the testing of any type of weapon.” The difference in these two regimes should be noted. The specific ban of all weapons only applies to celestial bodies, whereas the ban on WMD only applies to space in general. By implication, therefore, it can be said that conventional weapons and military activities are legal in the void of space under the terms of the Outer Space Treaty. A further question arises as to what constitutes a WMD being placed or stationed in space, since ICBMs armed with nuclear warheads, which are considered a legal defensive weapon terrestrially, would traverse space in their ballistic trajectory. The United States and the Soviet Union seemed to agree that to be placed in space a weapon would need to complete a full orbit of the Earth (Garthoff, 1980–1981).

Accountability Mechanisms

Articles VI, VII, and VIII represent mechanisms through which states undertake to ensure to other states that they will be accountable for their space activities (cf. UNGA, 1963, Principles 5, 7, and 8). This set of mechanisms also consists of obligations, but these obligations have more ambiguity in their application than those discussed in the previous subsection.

Article VI is the foundation to the responsibility regime, and it is a unique treaty clause in international law. Generally, states are not to be held internationally responsible for the actions of their nongovernmental actors unless some form of agency can be established that links the nongovernmental actor to the state (International Law Commission, 2001, Chap. II). Article VI, on the other hand makes states “internationally responsible for the national activities” of their nongovernmental actors, regardless of whether agency can be established. It couples this burden with a duty that states “authorize” and “continually supervise” their nongovernmental actors’ space activities. The reasoning behind this provision can be attributed to the ambiguous nature of space activities. It is very difficult to determine the operations of any given satellite and who is operating it, thus Article VI removes a layer of ambiguity through which a state might argue that they were not connected with a space activity. Article VI then serves to assure all states that all space actors, even those not directly under the control of a state, are operating in compliance within the bounds of the international legal regime. This is important context in a strategic environment.

Article VII extends the idea of international responsibility (which is connected to breaches of international law) and makes states liable for damage caused by its space objects. This treaty provision was later expanded on in the 1972 Liability Convention, which imposes a two tiered system of liability on “launching states” (Convention on International Liability for Damage Caused by Space Objects [Liability Convention], 1972, Art. I). A strict liability regime applies to damage caused on the surface of the Earth, including damage caused to aircraft in flight, and a fault-based liability regime applies to damage caused in space Liability Convention, 1972, Art. II–III). Similar to the responsibility provisions, this provision and its follow-on treaty are meant to ensure that states behave responsibly in space by placing burdens on noncompliant behavior. Liability under these provisions has only been appealed to once, in the case of Cosmos-954, a Soviet nuclear-powered satellite that impacted Canadian territory in 1977 (Protocol Between the Government of Canada . . . , 1981). Though Canada invoked the liability regime, the parties settled the dispute diplomatically.

Finally, Article VIII states that the state “on whose registry an object launched into outer space is carried shall retain jurisdiction and control over such object.” Article VIII thus requires states to maintain a registry of their space objects and to affirmatively retain jurisdiction and control over those objects. Article VIII serves to bolster the security assurances found in Articles VI and VII by further strengthening the links of attributability by imposing jurisdiction on a specific state. The wording of this provision is key, in that states “shall retain,” which not only gives states a right to exercise jurisdiction, but also places an affirmative burden of jurisdiction on them. If a harmed or damaged state is seeking to determine the state to which it should address its grievances, then this provision seeks to require that there be at least one state that cannot shirk that responsibility. The concept of registration is poorly defined in Article VIII and was expanded on in the 1974 Registration Convention, which requires states to maintain a registry and to provide information to the UN Secretary General for inclusion in a register of space objects maintained by the UN (Convention on Registration of Objects Launched into Outer Space [Registration Convention], 1974, Arts. II, III, and IV; see also UNGA, 2007, Res 62/101).

Socialization Mechanisms

The final set of mechanisms in the Outer Space Treaty that are intended to enhance international peace and security are socialization mechanisms. These are softer mechanisms that are meant to create engagement on space among states within the international community structure established under the UN Charter. These mechanisms seek to socialize states through cooperation and communication in the space domain, and the intent is that, through such socialization, space will be secured by building trust and confidence among states. The mechanisms are directly related to the concept of “friendly relations” and peaceful dispute resolution advanced by the UN Charter (UN Charter, 1945, Art. 1).

The first set of these obligations are aspirational in nature, but build on the non-territoriality of outer space. They seek to frame space as a place meant to serve the entirety of the human population. Article I of the Outer Space Treaty states that the use and exploration of space is the “province of mankind,” and that such use and exploration is to be executed for the “benefit and in the interest of all countries,” regardless of their respective state of development. This provision is based on Principle 1 of Resolution 1962 (XVIII), but is a reformulation of the principle, which states that “[t]he exploration and use of outer space shall be carried on for the benefit and in the interests of all mankind.” Regardless of this reformulation, this principle is meant to give states an obligation to use space in such a way that it benefits the global population rather than their respective national populations. While it cannot be said to go as far as requiring equal benefit sharing across the globe, it is a significant statement by the negotiators of the treaty on how states should conduct their space activities (see also UNGA, 1996, Res. 51/122). This idea is further bolstered by Article V of the treaty, which declares that astronauts are “envoys of mankind.” While the bulk of that article is concerned with the protection of astronauts, which includes protecting them from interrogation in cases of emergency landings (Ramey, 2000, pp. 150–153), the envoys of mankind language indicates that these individuals represent the global population rather than their respective states, an idea supported by the plaque attached to the Apollo 11 landing module that stated “[w]e come in peace for all mankind” (NASA, n.d., “Apollo 11 Plaque Left on the Moon).

The second group of socialization mechanisms emphasizes the value of international cooperation in space (cf. UN Charter Art. 1[3]). The value placed on international cooperation can be seen in its prevalence throughout the Outer Space Treaty. The phrase is found in the Treaty’s preamble and in Articles I, III, IX, X, and XI. It is further implied in the assistance and reciprocity components of Art. V, VII, and XII. The obligation to engage in international cooperation is, for the most part, aspirational in scope and gives no specifics as to the extent to which states should engage in these activities. So for instance, the United States and the USSR, though adversaries, have engaged in extensive space cooperation (Sagdeev, n.d.), while the United States in the early 21st century has refused to engage in cooperative activities with China despite the fact that the two countries are major trading partners (Beldavs, 2015). Regardless, the concept of international cooperation is a critical component of the space security regime, which is illustrated by annual adoption, by the UNGA, of a resolution titled “International Cooperation in the Peaceful Uses of Outer Space” that emphasizes the role of cooperation in space security (UNOOSA, n.d., “Documents and Resolutions Database”).

The final set of mechanism seeks to encourage information sharing regimes to bolster trust between states with regard to their space operations. Due to the opacity of space activities, it can be difficult to discern a peaceful use from a non-peaceful use. A not insignificant example is that an early warning system would be unable to discern the difference in the plumes created by a space launch vehicle and an ICBM. To this end, the negotiators built in informational exchanges as a way to increase security in space. Article VIII and the Registration Convention requires states to share basic information on space objects launched into space (Convention on Registration of Objects Launched into Outer Space [Registration Convention], 1974, Art. IV; for a supplemental information sharing regime, see also International Code of Conduct Against Ballistic Missile Proliferation, 2002). Article IX implements a reciprocal duty between states in cases of “potential harmful interference.” If a state thinks that it may cause harmful interference to another state or be a victim of another state’s harmful interference in space, then that state “may request consultation” with the other state (Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies [Outer Space Treaty], 1967, Art. IX; for further discussion, see Blount, 2011, pp. 33–35). This provision falls far short of a formal dispute resolution mechanism, which is absent from the Outer Space Treaty, but it again represents an effort by negotiators to encourage states to exchange information in order to support secure and safe space activities. Finally, Articles X, XI, and XII of the treaty all have information sharing components that fulfill similar goals.


Since the outer space legal regime is intended to prevent conflict in outer space, and Article IV of the Outer Space Treaty leaves open the possibility of conventional weapons placed in space, then a critical question for space activities is the legality of weaponization. The history of arms control in space begins before the adoption of the Outer Space Treaty. The Partial Nuclear Test Ban Treaty of 1963 prohibited state parties from engaging in nuclear tests in outer space, the atmosphere, and underwater, but the international community has never adopted formal legal measures to ban non-WMD weapons from space.

Efforts have been made to advance the non-weaponization, namely under the banner of the Prevention of an Arms Race in Outer Space (PAROS). PAROS can be seen at the international level in both the UNGA and the Conference on Disarmament (CD). The UNGA currently passes annual resolutions that requests states to engage in adopting measures related to PAROS (e.g., UNGA, 2016, Res. 71/31) and on Transparency and Confidence-building Measures in Outer Space Activities (e.g., UNGA, 2016, Res. 71/42). Also of note, in 2014 the UNGA adopted Res. 63/32, which attempted to get states to pledge to a no first placement of weapons in space policy, and this resolution has been adopted annually since (UNGA, 2014, Res. 69/31; UNGA, 2016, Res. 71/32). These efforts have had a significant detractor in the United States, which has vacillated between negative votes and abstentions on PAROS resolutions. The CD is the international body tasked with negotiating multilateral disarmament agreements, and PAROS is part of its mandate. However, due to procedural rules, which require the CD to adopt a Program of Work annually and by consensus, it has been deadlocked for close to two decades, and has been unable to make headway in the matter. This was due in part to the Bush Administration’s space policy in the United States, which was to not take part in any negotiations on new rules for outer space (White House, 2004). That administration vetoed any Program of Work that included PAROS, and the Russian Federation vetoed any Program of Work that did not include PAROS. This policy changed under the Obama Administration in 2009, but the CD remains deadlocked based on other issues, including fissile materials.

There have been two recent agreements that were intended to advance the cause of keeping space de-weaponized. The first is the draft Treaty on the Prevention of the Placement of Weapons in Outer Space (PPWT), which was introduced in the CD by Russia and China in 2008 (CD, 2008a). This draft text would ban states from placing conventional weapons in outer space, but has been criticized for its lack of verification mechanisms, for allowing Earth to space weapons deployment, and for placing no restrictions on development of these weapons (CD, 2008a, Art. II; CD, 2008b). Further, since this document was introduced as a multilateral disarmament treaty to the CD, it will not advance unless the deadlock of the CD can be broken. The second agreement is the European Union Code of Conduct (EUCOC) (Council of the European Union, 2010; see generally Meyer, 2014). This is a nonbinding agreement that was brought forward by the European Union. In light of the lack of progress at the CD, the EU opted to use a nonbinding agreement, which would fall outside the CD mandate. This agreement seeks to ensure responsible behavior by states in space and includes provisions that require participants to refrain from ASAT testing, but it also contains a controversial provision that acknowledges a state’s inherent right to self-defense. This agreement went through three rounds of international consultations before the EU called for a formal negotiation in 2015. These negotiations failed for a variety of reasons, and the future of the agreement is unclear (Blount, 2018).

To date, there is no verified placement, by a state, of a weapon in Earth orbit. However, three states have engaged in ASAT tests: USSR, US, and China (Grego, 2012). The bulk of this activity occurred in the 1970s and 1980s, after which the United States and the USSR entered into a voluntary moratorium on ASAT tests (Grego, 2012). This moratorium was broken when China tested an ASAT in 2007, and the United States followed suit in 2008. These showings of ASAT capability mean that possibly one of the most salient places to look for legal restrictions on space weapons is the international law of armed conflict (LOAC). LOAC is a specialized branch of international law that applies when states are engaging in hostilities, and its application to outer space is confirmed by Article III of the Outer Space Treaty (see generally Blount, 2009, 2012; Bourbonnière & Lee, 2007; Ramey, 2000). Further, it has provisions on weapons that affect the legality of weapons outside of an armed conflict. To this end, states are required to do a legal review of weapons that they develop to ensure that these weapons are compliant with the law (Protocol Additional to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of International Armed Conflicts [API], 1977, Art. 36). Importantly for outer space, states cannot deploy weapons that are indiscriminate in nature, meaning that the weapon must be able to be used in such a way that they can be targeted specifically at military targets and avoid unduly affecting civilians or civilian objects (API, 1977, Arts. 52–53; Blount, 2012, pp. 5–6). Kinetic antisatellite weapons can cause large debris clouds that could place civilian objects (satellites) and civilians who rely on satellite services at risk, which may mean that they rise to the level of an indiscriminate weapon. Further, both Additional Protocol I to the Geneva Convention and the Environmental Modification Convention (ENMOD), ban states from using environmental change as a tactic in armed conflict (Protocol Additional to the Geneva Conventions of 12 August 1949, and relating to the Protection of Victims of International Armed Conflicts [API], 1977, Art. 35; Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Techniques, 1977, Art. I). The long-term effects of space debris may be precluded by this treaty (Blount, 2012, pp. 20–21). These limitations would apply to those weapons that destroy a satellite causing it to break up on orbit, which has been the method of all ASATs to date; however, new capabilities based on cyber or on-orbit servicing capabilities, which would avoid debris creation, would like not run afoul of LOACs bar on indiscriminate effects.

National Security

Though the core goal of the space treaty regime is the maintenance of international peace and security, it must be remembered that this task was to be accomplished in an international governance system that made sovereign equality a foundational notion. The result is that each state is free to pursue its own national security goals as long as those goals do not impinge on international peace and security. This means that states are free to develop defensive and offensive military capabilities as long as those capabilities do not threaten international peace and security. As the nuclear build-up of the Cold War illustrates, there are few limitations on the development of such capabilities. Indeed, the primary limitation on a state is not the mere possession of a capability, but how a state uses that capability (Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion, 1996). Thus, an aggressive use of a weapon not sanctioned by the UNSC would be illegal, but a defensive use of the same weapon under UN Charter Article 51 and the residual “inherent right to self-defense” would be legal.

Space has become an integral component to many state’s national security regime. This section addresses the central legal concerns that states have in implementing and controlling space technology for national security regimes. Issues are discussed pertaining to disarmament, protection of space assets on orbit, and the protection of space technology from proliferation. Each of these areas has significant crossover with the international legal regime discussed in the previous section, but the goal here is to discuss general mechanisms, both domestic and international, that states use to provide for national security.


As noted, concern about the weaponization of space has been a constant theme in international space law. Space technology, however, also offers the potential to enable disarmament mechanisms for terrestrial weapons as well. Remote sensing capabilities give states a unique tool for verification of disarmament agreements.

Verification is a critical component to any disarmament agreement. In the 1950s, one of the roadblocks to drawing back the arms race between the United States and the USSR was the inability to verify any arms limitation agreement due to Soviet opposition to on-site inspections of their nuclear facilities. The United States was limited to intelligence it gathered through its U-2 program, which used high altitude planes to surveil the territory of other states. This program came to a halt over Soviet territory after the shooting down of a U-2 aircraft in sovereign Soviet airspace in 1960. The United States, though, was already working on developing remote sensing capabilities to gather intelligence on USSR military capabilities. Indeed, when Sputnik was launched, it was unclear whether a satellite would have the right to overfly another nation’s territory. As Sputnik circled the Earth, one advisor to President Eisenhower put a positive spin on the event by noting that the Soviet’s “did us a good turn” by establishing that right (Memo on Sputnik, 1957). As a result, satellite capabilities and disarmament verification became intrinsically linked.

The legal status of these capabilities can most readily be seen in the bilateral disarmament agreements between the United States and the USSR, and later Russia (namely, US Department of State [ABM], 1972; US Department of State [SALT I], 1972; Strategic Arms Reduction Treaty I, 1993; and Strategic Arms Reduction Treaty II, 2002). Each of these treaties states that the parties “shall use national technical means of verification” (NTM) to ensure compliance with the respective treaty. Further, each of these treaties requires that “each of the parties undertakes not to interfere” with the NTM of the other. NTM was chosen as an oblique phrase that kept the parties from disclosing specifics about their technical capabilities, but it was understood to primarily consist of remote sensing satellites. This was publicly confirmed in 1978 in a speech by US President Jimmy Carter, who stated that “[p]hotoreconnaissance satellites have become an important stabilizing factor in world affairs in the monitoring of arms control agreements” (Carter, 1978).

One of the most important features of NTM as used in these treaties is that each treaty contains a non-interference provision. Because of the technical difficulties involved in knowing what the functions of a satellite in orbit are, it has been argued that the legal obligation not to interfere with NTM served, during the Cold War at least, as a keystone in protecting all satellite infrastructure (Harrison, n.d., 9–10). This line of reasoning holds that because of the opaqueness of space operations, any satellite on orbit could be used for NTM, therefore the obligation not to interfere applies to all satellites. In this regard, the NTM obligation advances the Outer Space Treaty’s Article IX obligation to seek consultations in cases where there might be “harmful interference” and hardens it into a more salient obligation. It should be noted that NTM non-interference exists as a bilateral rather than multilateral obligation. While it bound the two states with motive and capability for interference during the Cold War, it can no longer be understood to be as strong a limitation as it was historically.

Protection of Space Assets

States use a number of mechanisms to ensure that their space assets, in particular military assets, are protected on orbit. The bulk of these measures are strategic and technical in nature, such as on-orbit redundancy and hardening of circuits against electrical impulses. Some of these mechanisms have legal components. This section will briefly discuss the legal issues related to Space Situational Awareness (SSA) and to cybersecurity for satellites.

SSA data is required by all satellite operators to avoid collisions between satellites. Currently the most comprehensive SSA collection is done by the military Joint Space Operations Center (JSPOC), which functions as part of the United States Strategic Command (STRATCOM). JSPOC collects SSA data primarily to ensure the safety of the space assets of the United States and its allies. However, as part of this mission, it completes a daily conjunction analysis that is distributed to all operators that it has contact information for, and it makes specific contact with operators that are at risk (Space Traffic Management, 2014, p. 108). Thus while JSPOC has a domestic military mission, its data is used for worldwide knowledge on safety operations. To this end, JSPOC has entered into bilateral data sharing agreements with both governmental and commercial entities to increase the quality of its data (Hearing on National Defense Authorization Act, 2013, p. 101). Recently, though, there has been discussion of moving this capability out of JSPOC to a civil agency and adopting an open data platform for all users (FAA/AST, 2016). Such a move may be the beginnings of a Space Traffic Management (STM) system for the United States and possibly for the world (Space Traffic Management, 2014, pp. 51–64). Establishing such a system could lead to better management of space assets for safe and secure operations. It does have risk, however, in that it would make military satellites much easier to target by adversaries; thus, the future of such a regime will likely depend on the law’s ability to ensure that states do not feel as though their national security is compromised.

SSA seeks to protect satellites from physical threats in space that may cause collision, but the new threat of cyberattacks is beginning to be realized for space assets. Cyberattacks take advantage of the networked nature of satellites to compromise, take control, or disable satellites or their systems or subsystems. This presents a clear strategic advantage, as it would result in a debris-free ASAT. While there have been no documented attacks that rise to this level, there are numerous examples of cyber exploits that take advantage of satellites (Blount, 2017, pp. 279–280). A full discussion of cybersecurity for satellites is beyond the scope of this article, but cybersecurity present significant legal issues in the national security realm (see generally, Blount, 2017; Mejia-Kaiser, 2013; Petras, 2002; Rendleman & Ryals, 2013; Wingfield, 1998). Internet Protocol (IP) based network technology creates an open network that adversaries and criminal actors may take advantage of to access satellite systems. States must rely on criminal statutes in order to prosecute these actors, but these actors are most likely to be located outside of their jurisdiction. This means that states should focus their law and policy on prevention to protect their space assets and capabilities. At this time, there are no generally accepted standards and no legal standards that apply to the satellite industry, leaving cybersecurity to be governed by more general standards, laws, and policies.

Export Controls and Non-Proliferation

The fact that space technologies can be a key enabler of advanced weapons technologies has led to many states to attempt to block the proliferation of this technology to other states that may weaponize it. Nonproliferation measures are primarily concerned with the export of weapons technology to other states, and the category of weapons technology often includes both launch vehicles and spacecraft technology.

At the international level, the multilateral Wassenaar Arrangement on Export Controls for Conventional Arms and Dual-Use Goods and Technologies serves as the framework through which states agree on which items should be controlled (Wassenaar Arrangement, n.d., “About Us”). The Arrangement itself is not a binding regime, but participating states agree to maintain export control lists and to work towards transparency in munitions exports (Wassenaar Arrangement, 2017a, pp. 4–5). Space technology is included on the agreed upon control list, with an emphasis on launch vehicles, which are easily repurposed as ICBMs (Wassenar Arrangement, 2017b). Similarly, the Missile Technology Control Regime (MTCR) has established guidelines on the export of missile and rocket technology. Like the Wassenaar Arrangement, the MTCR is not based on a binding agreement, but its participating states have agreed “to limit the risks of proliferation of weapons of mass destruction (i.e., nuclear, chemical, and biological weapons), by controlling transfers that could make a contribution to delivery systems (other than manned aircraft) for such weapons” (Missile Technology Control Regime [MTCR], n.d.). The guidelines adopted by the MTCR “are not designed to impede national space programs or international cooperation in such programs as long as such programs could not contribute to delivery systems for weapons of mass destruction” (MTCR, n.d.). The MTCR technical annex on technology that should be controlled includes space launch technology (MTCR, 2017, 1.A.1 & 19.A.1).

These international regimes must be implemented at the national level in the export control lists of the participating states. With regard to space technology, the United States International Traffic in Arms Regulations (ITAR) has become one of the most notorious of these domestic regimes (Gold, 2008). This is because, until 2014, ITAR classified all space technology, including component parts and technical data, as a weapon on the US Munitions List (USML). This meant that to export a satellite a commercial company would need to get an export license from the US Directorate of Defense Trade Controls. The US space and satellite industry complained that this process was burdensome and that the regulations were hurting the industry in the international marketplace. In 2014, significant portions of the space technology previously categorized as munitions were re-categorized as dual-use and moved to the US Department of Commerce export control list (Department of Commerce, 2014; Department of State, 2014). Dual use items still require an export control license, but the process is less burdensome than under the ITAR regime.

Contrasting the US position is the EU regime. While each state of the EU has the competency to establish its own export control list, dual-use items fall within the bounds of EU competency (Mineiro, 2011, pp. 216–217). EU regulation No 388/2012 sets out a control list that is much more similar to the controls undertaken in the Wassenaar Arrangement (European Union, 2012). Launch vehicles are controlled under this regulation, but only specific components of satellites are subject to export controls (European Union, 2012, 9A004). As a result, EU export control regulations have generally been understood to be more permissive than US regulations. This may remain the truth even after the reform of the ITAR.

Human Security

As noted, the benefits language in Article I of the Outer Space Treaty is highly aspirational, but it does represent an early attempt at recognizing the concept of human security. The concept of human security seeks to refocus the security lens from national borders to the individuals and populations that reside in and across those borders (United Nations Trust Fund for Human Security, 2009, pp. 5–6). The benefits language is a significant attempt at linking the emerging space regime to the human rights regime that became part of international law post WWII. Space plays a role in a number of sectors in bringing benefits to human populations, but remote sensing capabilities are the most closely linked to human security. This can be seen in disaster response and in its potential to support human rights.

Disaster Response

Natural and manmade disasters are often easily seen from space, and space plays a critical role in responses to these disasters. There is no formal legal regime governing the use of space for disaster response, but there are mechanisms that guide both state and nonstate actors. The use of remote sensing for disaster management is part of the UNGA’s Principles on Remote Sensing, which state that “[r]emote sensing shall promote the protection of mankind from natural disasters,” and encourages states to make available remote sensing data to affected states (UNGA, 1986, Resolution 41/65). There are several international frameworks that promote space capabilities for disaster management.

The first of these is the Disasters Charter (Charter on Cooperation, 2000; see also Beets, 2010). This is a voluntary agreement with both state and non-state participants. The participants in this regime have agreed to provide assistance to affected states when the Charter is formally activated by a requesting party. To the extent feasible, these actors provide data to a state that has been subject to a disaster to better help that state respond to that disaster. While this agreement is nonbinding, it represents significant international cooperation in coping with the effects of disasters.

A second regime is that of UN-SPIDER, which is under the direction of the UN Office of Outer Space Affairs (UNOOSA). The United Nations Platform for Disaster Management and Emergency Response (UN-SPIDER) was established by UNGA Resolution 61/110 in 2006 (UNGA, 2007, Resolution 61/110). The mission of UN-SPIDER is to “[e]nsure that all countries and international and regional organizations have access to and develop the capacity to use all types of space-based information to support the full disaster management cycle” (UN-SPIDER, n.d.). UN-SPIDER differs from the Disasters Charter in that it attempts to use space-based capabilities not just to respond to crises, but through “all phases of the disaster management cycle, including the risk reduction phase” (UN-SPIDER, n.d.).

A third regime is a legal regime, but is not directly related to space activities. The Tampere Convention is a treaty for the provision of telecommunications services for disaster mitigation (Tampere Convention on the Provision of Telecommunication Resources for Disaster Mitigation and Relief Operations, 1998). According to Article 3(2)(a), these services may include satellite communications. The provision of telecommunications infrastructure is a significant question of sovereignty for any nations, and while this treaty was an attempt to mitigate this problem its efficacy has been questionable (Rahrig, 2010, pp. 283–286).

Human Rights

The ability of satellites to observe and verify terrestrial activities has been recognized since the very beginning of the space age, but has only been generally accepted as a means of verification in disarmament treaties (Hettling, 2003). States have been unwilling to adopt these capabilities into environmental or human rights regimes for a variety of reasons, but mainly based on issues related to state sovereignty. These capabilities though have not gone unused, and both international and nongovernmental organizations have employed these technologies.

Both the UN High Commissioner on Human Rights (UNHCHR) and the UN High Commissioner on Refugees (UNHCR) have employed remote sensing data to make public human rights violations and issues. Additionally, the prosecutor of the International Criminal Court (ICC) has used remote sensing evidence to prosecute individuals accused of international crimes (Macauley, 2013; Williams, 2013). The use of satellite data as evidence is well accepted, though it will need to need to conform to the evidentiary rules of a given legal forum to be accepted in court (Shipman, 2013).

The use of satellite data to prevent human rights atrocities is less accepted. NGOs such as the now defunct Satellite Sentinel Project attempted to gather and distribute data to prompt action in this realm. The Satellite Sentinel Project, which has folded its operations into The Sentry, gathered remote sensing data to publicize possible genocide in Sudan (Satellite Sentinel Project). Since one of the key notions in the Genocide Convention is the “prevention” of genocide, this type of use seems to be in line with the purpose and scope of the treaty (Convention on the Prevention and Punishment of the Crime of Genocide, 1951). Indeed, the use of space to bolster human security seems to not be inhibited so much from legal roadblocks, but instead by a lack of legal implementation. Using remotely sensed data in this way is consistent with the benefits language of Article I of the Outer Space Treaty, but states have no affirmative obligation to share and use this data.

A salient example could be the emerging idea of the “responsibility to protect” (see generally Bellamy, 2006). Under this concept, the international community would reserve the right to intervene when a state failed to fulfill an obligation to protect its populace as a form of humanitarian intervention. Specifically, this would be used in cases in which the state was directly responsible for crimes against its own people. This concept is controversial under international law for a number of reasons, but if it were to emerge as a principle, one of the questions would be how to determine the extent of the failure by a state. Satellite data would have a specific role to play in this respect, but states would need to be responsible for disseminating this data to the proper international authority to make the principle effective. Until there is an affirmative obligation to share this type of data at the international level, remote sensing data will likely only be a part of the evidence used in prosecution rather than a true tool of prevention in the realm of human rights.

Security of the Space Environment

The previous sections of this article have dealt with the concepts of using space to secure the terrestrial sphere. Many of the mechanisms discussed would in effect help protect the space environment from damage, but their main purpose is to ensure security on the surface of the Earth. Article IX of the Outer Space Treaty does require states to conduct space activities “so as to avoid their harmful contamination.” There are two specific concerns with regard to the harmful contamination of space: space debris and planetary protection.

Space Debris

Space debris is, in very simple terms, junk that is in Earth orbit consisting for the most part of nonfunctional spacecraft and fragments of spacecraft. Due to the physics of space, when an object is placed in orbit, it will remain there until such time as it is removed or until its orbit finally degrades and it re-enters the Earth’s atmospheres. Depending on the orbit of an object, this can take from years to decades to centuries. Space debris poses a significant threat to space operations as on-orbit collisions can be catastrophic events leading to the creation of more debris. The Kessler Syndrome is a term used to describe a situation in which debris collisions cause debris to grow exponentially in a cascading effect, which could eventually destroy human ability to use Earth orbit (Kessler, Johnson, Liou, & Matney, 2010). Debris is a major concern for all actors in space as it threatens the safe and secure operations of all spacecraft.

Despite the fact that space debris represents a pressing issue for all operators, outside of Article IX there are no legal texts that govern debris creation. Instead, states have relied on technical guidelines on debris mitigation to reduce the amount of debris created. The Inter-agency Debris Coordination Committee (IADC), which is a cooperative effort among 11 global space agencies, has adopted technical Debris Mitigation Guidelines (2007). These Guidelines were later adopted by UNCOPUOS and the UNGA, respectively, and have been implemented at the domestic level by a number of states (on domestic implementation, see Mirmina, 2004). While these guidelines represent best technical practices, they do not rise to the level of binding law, except within the domestic legal systems in which they have been adopted. They may, however, be of significant interest if a question of fault liability were to arise from a collision in outer space caused by debris.

Currently, a new effort is under way at UNCOPUOS to develop Guidelines on the Long Term Sustainability of Space. These guidelines are also not intended to create legal requirements for debris mitigation but, instead, to set out best practices for states to preserve the environment of space. These guidelines are to be adopted in two separate sets that will then be submitted to the UNGA for adoption as a formal resolution (UNOOSA, n.d., “Long-Term Sustainability”). The first set of guidelines was adopted in 2016. The guidelines are not explicitly devoted to space debris, but overall would serve to help slow the creation of space debris. Specifically, these guidelines request that states share information on space debris and SSA to prevent further collisions and breakups on orbit (United Nations Committee on the Peaceful Uses of Outer Space [UNCOPUOS], 2016, Guidelines 12–13). They also request that states seek to develop new ways of dealing with the space debris problem (UNCOPUOS, 2016, Guidelines 27–28).

Planetary Protection

Another concern of the scientific community is that space exploration may contaminate the sites that spacecraft visit. For example, if a spacecraft were to land on Mars carrying Earth-born bacteria that is able to propagate itself on the Martian surface, then scientists may be unable to ever determine whether life exists or existed independently on Mars.

Again, outside of Article IX, there are no international rules in this regard. There are however, accepted technical standards that have been adopted by the Committee on Space Research’s (COSPAR) Panel on Planetary Protection (Committee on Space Research [COSPAR], n.d.). These guidelines separate space operations into different categories and discuss the proper safeguards that should be taken to ensure that forward contamination from the Earth to space does not despoil celestial bodies, and that back contamination from space to Earth does not damage the surface of the Earth (COSPAR, 2005).

Similarly, there have been efforts to protect historical sites on celestial bodies such as the site of the Apollo landing (David, 2013; SSERVI, n.d.). These efforts have primarily been attempts to pass US legislation declaring them national historic sites. As yet, these laws have not passed, and the efficacy of doing so is unknown.


Space security is a diverse concept that touches on all aspects of security. This article is a basic introduction to some of the core concepts and is as comprehensive as possible within the limited space. Space security law itself is still emerging, and as space technology continues to evolve, it will be a constant challenge for the law to keep pace with the innovations. Further, as new state and commercial actors begin to take part in space activities, the security environment will continue to evolve and change. Specifically, many of the assumptions that supported space security law during the Cold War will be subsumed by new circumstances, and while the core principles of space law will likely remain applicable, interpretations of them will need to adapt in order to maintain space as a safe, secure, and sustainable environment that, by maintaining global security, serves the benefit of all humankind.

Further Reading

  • Beets, J. (2010). The International Charter on Space and Major Disasters and international disaster law: The need for collaboration and cooperation. Air & Space Lawyer, 22(4), 12–15.
  • Blount, P. J. (2011). Developments in space security and their legal implications. Law/Technology, 44 (2), 18–39.
  • Blount, P. J. (2012). Targeting in outer space: Legal aspects of operational military actions in space. Harvard National Security Journal.
  • Blount, P. J. (2017). Satellites Are Just Things on the Internet of Things. Air and Space Law, 42, 279–280.
  • Garthoff, R. L. (1980–1981). Banning the bomb in outer space. International Security, 5(3), 25–34.
  • Grego, L. (2012). A history of anti-satellite programs. Union of Concerned Scientists.
  • Harrison, R. G. (2011). Space and verification, Vol. 1: Policy implications. USAFA, CO: Eisenhower Center for Space and Defense Studies.
  • Hettling, J. K. (2003). The use of remote sensing satellites for verification in international law. Space Policy, 19, 33–39.
  • Macauley, D. E. (2013). The use of EO technologies in court by the office of the prosecutor of the International Criminal Court. In R. Purdy & D. Leung (Eds.), Evidence from earth observation satellites: Emerging legal issues (pp. 217–240). Leiden, The Netherlands: Martinus Nijhoff.
  • Marchisio, S. (2005). The evolutionary stages of the legal subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS). Journal of Space Law, 31, 219.
  • McDougall, W. A. (1985). Heavens and the earth. New York: Basic Books.
  • Meyer, P. (2014). The diplomacy of space security: Whither the International Code of Conduct? Simons Papers in Security and Development. No. 38/2014. Vancouver, Canada: Simon Fraser University.
  • Mineiro, M. (2011). An inconvenient regulatory truth: Divergence in US and EU satellite export control policies on China. Space Policy, 27, 213–221.
  • Mirmina, S. A. (2004). The regulation of orbital debris through national measures. Air and Space Law, 29(2), 137–146.
  • Petras, C. M. (2002). Use of force in response to cyber-attack on commercial space systems-reexamining self-defense in outer space in light of the convergence of US military and commercial space activities. Journal of Air Law & Commerce, 67, 1213.
  • Ramey, R. A. (2000). Armed conflict on the final frontier: The law of war in space. Air Force Law Review, 48, 150–153.
  • Wright, D., Grego, L., & Gronlund, L. (2005). The physics of space security: A reference manual. Cambridge, MA: American Academy of Arts and Sciences.