1. INTRODUCTION: DEFINING THE SPACE SECURITY

On 4 October 1957, the Soviet Union launched Sputnik I into low Earth orbit, inaugurating an era in which outer space became a theatre for geopolitical competition. The response of the international community was swift: within a decade, the Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, Including the Moon and Other Celestial Bodies — universally known as the Outer Space Treaty (OST) — had been negotiated, signed, and entered into force. The OST established the foundational axioms of space law: that outer space is the province of all mankind, that no state may appropriate it by claim of sovereignty, and that celestial bodies may be used exclusively for peaceful purposes.

In the contemporary geopolitical landscape, outer space has transcended its origins as a laboratory for scientific curiosity to become a cornerstone of national power. As a scholar of international law, I frequently categorize this evolution through two distinct lenses: “Space for Security” (the utilization of orbital assets to bolster terrestrial defense) and “Security for Space” (the protection of the orbital environment and assets from interference). Collectively, these form the basis of Space Security, a state where space activities are conducted with the necessary safety and stability to promote industry while shielding national interests (To understand this framework, one must grasp its three foundational pillars: ① Safety: The mitigation of unintentional risks, such as natural solar events, asteroid impacts, or accidental collisions with debris. ② Stability: The protection of assets from intentional interference and the cultivation of resilience—the capacity to rapidly recover functional capabilities following an attack or accident. ③ Sustainability: The governance of space as a finite resource, ensuring that orbital slots and radio frequencies remain available for future generations by discouraging irresponsible behavior).

“Space security” is not a single treaty-defined term; it is a problem-set. It concerns the conditions under which space systems (satellites, ground segments, data links, and related services) remain safe, stable, secure, and sustainable against both intentional and unintentional harms—armed attack, coercive interference, misperception, accidents, and environmental degradation.

The legal challenge is structural: the foundational treaties were negotiated for a state-centric, low-density orbital environment. Yet the modern ecosystem includes (i) commercial operators providing strategically significant services, (ii) dual-use platforms and payloads, (iii) rapid-cycle deployment, and (iv) counterspace tools that are often non-kinetic and hard to attribute. The result is a classic governance mismatch: high operational interdependence and low clarity on prohibited conduct.

Space security law sits at the intersection of (i) international space law (governing peaceful exploration and use), (ii) general international law on peace and security (including the UN Charter rules on the use of force), (iii) arms control and disarmament processes, and (iv) technical regulatory regimes such as the ITU framework for radiofrequency interference. The field is under stress from congestion (mega-constellations), contested operations (jamming, spoofing, cyber intrusion, rendezvous and proximity operations), and renewed interest in counterspace capabilities — especially those that generate space debris.

This article maps the positive-law baseline (Outer Space Treaty and companion conventions), identifies the principal doctrinal gaps for modern threats, and evaluates the emerging turn toward “norms, rules and principles of responsible behaviours” in UN. It then proposes a pragmatic architecture for near-term legal ordering: (1) hardening interpretive obligations already embedded in space treaties (due regard, harmful interference, consultation), (2) codifying targeted prohibitions where consensus is achievable (notably on destructive direct-ascent ASAT testing), and (3) building verification-by-design through space situational awareness (SSA), notification, and incident response mechanisms [1].

2. WHY SPACE SECURITY MATTERS NOW

In the contemporary era, space has transcended its origins as a theater for scientific exploration to become a vital Strategic Asset. Our modern world operates within what sociologists term a “Risk Society”, where the same high-tech advancements that empower us - global communications, precision navigation, and real-time data- simultaneously expose us to unprecedented, borderless vulnerabilities.

The constitutional obligation has now expanded into the orbital domain. Protecting space is no longer an elective scientific endeavor; it is as essential to our sovereignty as the defense of our land, sea, and air borders.

Space security law draws on four overlapping layers : 1) International space treaty law (core baseline): the 1967 Outer Space Treaty (OST) , supplemented by the Liability Convention and Registration Convention (and, beyond this article’s focus, rescue/return and Moon Agreement instruments) [2]. 2) General international law on peace and security: the UN Charter prohibition on the threat or use of force (Art. 2(4)) and the inherent right of self-defence (Art. 51). 3) Technical regulatory regimes: especially the ITU Radio Regulations framework to prevent and remedy harmful radio interference. and 4) Soft law / political commitments / standards: UN COPUOS long-term sustainability (LTS) guidelines; UN processes on responsible behaviour (OEWG); and regional strategies such as the EU Space Strategy for Security and Defence [3].

Institutionally, “space security” is negotiated across two UN tracks that do not perfectly align: COPUOS (peaceful uses, sustainability, civil governance) and the UN First Committee/UNODA disarmament architecture (arms race prevention, military stability). The UN General Assembly has increasingly used the “responsible behaviours” framing to bridge this divide—explicitly via Resolution 76/231 establishing an Open-Ended Working Group (OEWG) [4].

2.1. Prevention of an Arms Race in Outer Space

The prevention of an arms race in outer space (PAROS) has featured on the agenda of the Conference on Disarmament since 1985, producing no negotiated instrument. Russia and China jointly tabled a draft Treaty on the Prevention of the Placement of Weapons in Outer Space (PPWT) in 2008 and revised it in 2014. The draft has been criticised for its failure to address ground-based ASAT weapons and for verification deficiencies. The United States and its allies have declined to support it. Nevertheless, the underlying imperative — constraining the deployment of weapons capable of threatening space assets — remains foundational to any credible space security regime.

A comprehensive instrument on PAROS would need to define ‘space weapon’ with sufficient precision to be operationally meaningful, without being so broad as to prohibit legitimate dual-use technologies. It would require robust verification mechanisms, including pre-launch notification, telemetry sharing, and on-orbit inspection protocols — challenges of considerable technical and political complexity. The precedent of the Intermediate-Range Nuclear Forces Treaty and the Chemical Weapons Convention demonstrates that such verification regimes are achievable, though not without sustained political will.

2.2. Critical Infrastructure Protection

Contemporary societies depend on space-based systems to an extent that was inconceivable in 1967. Global navigation satellite systems (GNSS) provide precise positioning, navigation, and timing signals that underpin civilian aviation, maritime transport, financial market synchronisation, electricity grid management, and emergency services. Communication satellites relay data, voice, and video traffic across continents. Weather and Earth observation satellites supply the data on which meteorological forecasting, agricultural planning, and disaster response depend. Military forces rely on space-based systems for intelligence, surveillance, reconnaissance, missile warning, and command-and-control.

Space security law must establish clear norms governing interference with these systems. The existing framework does not explicitly designate attacks on satellites as acts of aggression, nor does it specify what level of interference triggers the right of self-defence under Article 51 of the UN Charter. Jamming of satellite signals, cyber intrusion into satellite command systems, blinding of optical sensors with ground-based lasers, and the deployment of co-orbital spoofing platforms all constitute potential acts of hostility whose legal characterisation remains contested. Binding norms establishing the inviolability of critical space infrastructure — analogous to the protection afforded to civilian objects under international humanitarian law — are urgently required.

2.3. Attribution and the Law of State Responsibility

The law of state responsibility requires that a wrongful act be attributable to a specific state before international legal consequences attach. In outer space, attribution presents formidable challenges. Kinetic ASAT attacks generate debris signatures that may be misread as natural fragmentation events. Cyber operations against space systems are designed to be covert and may be launched through intermediary infrastructure in third states. Spoofing attacks manipulate GNSS signals without generating any observable physical effect. Co-orbital proximity operations that disable a satellite through directed electromagnetic interference may be indistinguishable from proximity manoeuvring conducted for legitimate inspection purposes.

Space security law must develop agreed evidentiary standards for attribution, together with proportionate response thresholds calibrated to the severity and reversibility of the interference. The risk of escalation based on misattribution — particularly where space and nuclear command systems are interlinked — argues for the establishment of dedicated communication channels and crisis management protocols, analogous to the Direct Communications Link established between Washington and Moscow in 1963.

2.4. Debris Governance and the Kessler Syndrome

Orbital debris constitutes perhaps the most acute near-term threat to the sustainability of space activities. Decades of launches, upper-stage explosions, and ASAT tests have seeded Earth orbit with millions of fragments ranging from defunct satellites to sub-centimetre particles capable of disabling operational spacecraft. In 1978, the astrophysicist Donald Kessler posited a cascading collision scenario — subsequently known as the Kessler syndrome — in which the density of orbital debris reaches a threshold at which collisions generate further debris at a rate exceeding natural atmospheric decay, rendering certain orbital regimes permanently unusable.

The legal framework governing debris is inadequate. The Liability Convention provides for compensation after damage occurs but does not prohibit activities that generate debris. Voluntary debris mitigation guidelines developed by the Inter-Agency Space Debris Coordination Committee (IADC) and endorsed by COPUOS recommend post-mission disposal within 25 years for satellites in low Earth orbit, but compliance rates have historically been below fifty percent. Active debris removal (ADR) — the retrieval or deorbiting of defunct objects — raises unresolved legal questions about consent, sovereignty, and liability. Space security law must address these gaps through binding mitigation standards, mandatory deorbit timelines, a liability regime that internalises the environmental costs of debris creation, and a legal framework for ADR operations.

2.5. Dual-Use Technology and Transparency Regimes

The dual-use character of space technology creates persistent ambiguity at the interface of civil and military space activity. A satellite capable of rendezvous and proximity operations (RPO) for debris removal or on-orbit servicing is structurally identical to one designed to disable or destroy an adversary’s spacecraft. A high-resolution imaging satellite serves both commercial and intelligence functions. A nuclear power source that enables deep-space exploration also powers a spacecraft capable of sustained co-orbital operations.

Transparency and confidence-building measures (TCBMs) can ameliorate, though not eliminate, this ambiguity. Pre-launch notification of RPO missions, the sharing of orbital manoeuvre data, the establishment of agreed exclusion zones around critical satellites, and joint monitoring arrangements can reduce the risk that benign activities are misinterpreted as hostile ones. Some of these measures are already practised informally; their consolidation in a binding legal instrument would enhance their effectiveness and extend their applicability to new entrants to the orbital environment.

2.6. Commercial Actors and the Accountability Gap

The Outer Space Treaty predates the commercial space industry as it exists today. Under Article VI, states bear international responsibility for the national activities of non-governmental entities in outer space and are required to authorise and continuously supervise such activities. This allocation of responsibility was designed for an era in which space activities were conducted by or under close governmental direction. It is poorly suited to a world in which private corporations operate constellations of hundreds or thousands of satellites, conduct launch services for clients in multiple jurisdictions, and provide space-based services to governments and civilians alike.

The accountability gap is threefold. First, national licensing regimes vary considerably in their stringency, creating incentives for regulatory arbitrage. Second, the continuous supervision requirement is operationally demanding where thousands of satellites are involved, and most states lack the technical capacity to exercise meaningful oversight. Third, novel business models — including on-orbit servicing, in-space manufacturing, and resource extraction — fall into legal grey zones that existing frameworks do not address. Space security law must establish harmonised minimum standards for national licensing regimes and develop new accountability mechanisms appropriate to the scale and diversity of commercial space activity.

2.7. Equitable Access and the Prevention of Orbital Monopoly

The geostationary orbit and the radio frequency spectrum are finite natural resources. Prime geostationary orbital slots — concentrated above population centres and key geographic regions — and the radio frequencies associated with them are allocated by the International Telecommunication Union (ITU) under a first-come, first-served regime that systematically advantages technologically advanced states. Developing states, which lack the capacity to occupy assigned slots, risk losing access to them through disuse, while the megaconstellations of major spacefaring states risk saturating low Earth orbit in ways that constrain future access for all.

The principle that outer space is the province of all mankind, enshrined in the OST, implies an obligation to ensure that the benefits of space access and use are not monopolised by a handful of states. Space security law must grapple with questions of distributive justice: how to reserve orbital capacity for future users, how to ensure that small island states and landlocked developing countries retain meaningful access to orbital resources, and how to govern the relationship between commercial constellation operators and states that lack the capacity to compete on equal terms. These questions are as much matters of security as of equity, since perceptions of exclusion and exploitation can generate the geopolitical resentment that fuels conflict.

3. THE GREAT PARADIGM SHIFT FROM R&D TO SECURITY

As articulated in the 4th Basic Plan for Space Development Promotion of ROK, the space security policy is moving away from a narrow focus on “Research and Development (R&D)” toward a comprehensive framework of space security, industry, and diplomacy.

This evolution is reflected in Korea’s strategic milestones: reaching expanded domestic infrastructure by 2030 and achieving global-tier capabilities by 2040. This shift brings three transformative changes: 1) Establishing Formal Legal Grounds: Moving beyond administrative guidelines to create “Space Security Laws.” This includes updating the legal legacy of the Outer Space Treaty (1967) — the “Magna Carta of Space” - to address modern challenges like the militarization of orbit. 2) Infrastructure Designation: Officially classifying space systems as Critical Information Infrastructure (CII), granting them the same protection status as power grids or financial networks against cyber-interference and physical attacks. 3) Global Strategic Cooperation: Active participation in international norms to prevent the “weaponization” of space while fostering alliances that ensure resilient orbital access [5].

3.1. Core principles relevant to security

The OST establishes freedom of exploration and use; non-appropriation; international responsibility for national activities (including private actors); jurisdiction and control over registered space objects; and a duty to conduct activities with “due regard” and avoid “harmful interference,” paired with consultation obligations.

Two points matter for security law: Article IV’s arms-control core is narrow: it prohibits placing nuclear weapons or other WMD in orbit and installing such weapons on celestial bodies; it also limits military installations and manoeuvres on celestial bodies, however, many conventional counterspace capabilities (kinetic or non-kinetic) are not expressly banned by the OST.

“Peaceful purposes” is not a blanket demilitarization rule. The treaty text itself contemplates uses of “military personnel” for scientific or other peaceful purposes on celestial bodies, strongly supporting the mainstream inference that “peaceful” is closer to “non-aggressive” than “non-military.” (Interpretive inference grounded in OST Article IV’s wording.)

3.2. The responsibility-liability-registration triad

Security incidents are often framed as “attacks,” but many are functionally damage events (collisions, debris creation, interference, loss of control). Here the companion conventions matter:

According to the Liability Convention, a launching state is absolutely liable for damage on Earth or to aircraft, and liable on a fault basis for damage occurring elsewhere (i.e., in space). Due to the Registration Convention, it requires states to maintain a national registry and provide information to the UN to facilitate identification and responsibility.

These regimes are indispensable for attribution and remedy, but they are not optimized for deterrence or crisis stability—especially for non-kinetic interference and cyber operations where “damage” can be reversible, indirect, or hard to quantify.

4. HARMFUL INTERFERENCE, JAMMING/SPOOFING, AND CYBER ATTACKS WHERE SPACE LAW MEETS ITU LAW

4.1. ITU law as a core security-relevant constraint

Many coercive acts in orbit are executed through the electromagnetic spectrum: uplink/downlink interference, GNSS spoofing, or control-link disruption. The ITU framework is central because it binds member states to apply the Radio Regulations and provides procedures to prevent and address harmful interference. Space law reinforces this through the OST’s duties of due regard and avoidance of harmful interference—though the OST is not a technical interference code.

4.2. Cybersecurity as space security law in practice

Cyber operations against space systems are now routinely treated as first-order threats because they can create mission loss without debris, and can also produce debris indirectly by inducing loss of control. A prominent example of state-driven norm articulation is U.S. Space Policy Directive-5 (SPD-5) on cybersecurity principles for space systems (Sept. 4, 2020), emphasizing lifecycle cybersecurity and resilience, including continuity of operations and the risk that malicious cyber activity could lead to harmful debris creation. While SPD-5 is national policy (not international law), it illustrates how “space security law” is increasingly compliance-through-licensing and standards, especially for commercial operators whose services are strategically embedded in national infrastructure.

4.3. Armed conflict in space is constrained by International Humanitarian Law

Even where states disagree on arms control, they increasingly accept that international humanitarian law (IHL/LOAC) applies when an armed conflict exists and operations are connected to it. The ICRC has contributed directly to the UN OEWG, urging norms that reduce risks to civilian populations, including resilience of satellite services used for humanitarian relief and emergency response.

This highlights a practical legal reality: many satellite services (communications, navigation, earth observation) are dual-use, and attacks on them can have severe downstream effects on civilian infrastructure. The governance task is to translate general IHL principles (distinction, proportionality, precautions) into operational expectations for space and counterspace planning — an area where state practice remains thin.

5. SUSTAINABILITY AS SECURITY: DEBRIS GOVERNANCE AND LONG-TERM ACCESS

The security of space systems is inseparable from the sustainability of orbital environments. UN COPUOS LTS guidelines frame sustainability as the ability to conduct space activities indefinitely while preserving the space environment for future generations - explicitly tying sustainability to continued peaceful use and equitable benefits. Legally, debris creation can convert “security competition” into collective denial of access; “due regard” and “harmful interference” become operationalizable through debris-mitigation expectations, conjunction analysis, passivation rules, and end-of-life disposal policies. In other words, sustainability instruments often function as security law by another name.

UNGA Resolution 76/231 created the OEWG on reducing space threats through norms, rules and principles of responsible behaviours, explicitly emphasizing risks from debris-generating destruction and instability arising from miscommunication and lack of transparency. The UN has continued to renew this agenda; for example, UNGA Resolution 78/20 (Dec. 4, 2023) was adopted 166-9-4, reflecting broad—though not universal—support for this normative pathway.

Norms-first approach is attractive because first it avoids definitional deadlock (“what is a space weapon?”), second it targets behaviours that create instability, and third it can be adopted incrementally and adapted to technology.

However, it might be risky because: first, it may substitute for binding constraints where those are needed, second it can be unevenly applied or strategically interpreted, and third verification and compliance remain under-specified. The best reading is that norms-first is not an end-state but a sequencing strategy: build shared expectations and verification capacity, then codify where feasible.

6. REGIONAL GOVERNANCE AND GLOBAL COOPERATION

6.1. EU Space Strategy for Security and Defence

The EU issued its first Space Strategy for Security and Defence (March 10, 2023), emphasizing that space is increasingly contested and highlighting threats including debris and hostile acts; it also links EU-owned constellations (e.g., Galileo, Copernicus, and IRIS2) to security interests. A Commission factsheet (March 18, 2024) reinforces this posture.

And the Artemis Accords (initiated 2020) are explicitly grounded in the OST and related treaties and aim to supply operational principles for civil exploration — transparency, interoperability, emergency assistance, deconfliction (“safety zones”), and debris mitigation. From a space security law perspective, their importance is structural: they show how coalitions generate practice that can later migrate into multilateral norms, especially on deconfliction and resource-related governance.

6.2. Global Cooperation and the Role of UN COPUOS

The institutional heart of space governance is the UN COPUOS (Committee on the Peaceful Use of Outer Space). Established in 1959, its mission is to foster international cooperation and resolve legal complexities arising from space exploration. Today, COPUOS is the primary venue for addressing three urgent security agendas: [6]

First, Developing guidelines for the Space Debris Management to mitigate the millions of artificial fragments that threaten orbital safety [7].

Second, Addressing kinetic and non-kinetic threats, including the devastating potential of high-altitude EMP weapons designed to incapacitate satellite constellations to mitigate the Anti-Satellite Weapon.

Third, Regulating the dual use technologies intended to disrupt, deny, or degrade space systems through electronic interference with Counterspace Weapons [8].

Furthermore, the PAROS (Prevention of an Arms Race in Outer Space) initiative remains the essential diplomatic forum for preventing military escalation. However, the governance landscape is shifting as the monopoly of the state gives way to commercial power.

7. TOWARD A WORKABLE LEGAL ARCHITECTURE

A realistic space-security regime should proceed along two complementary axes: the hardening of existing legal duties and the negotiation of a deliberately circumscribed set of new commitments selected for their observability and compatibility with verification. The first task is to operationalize the otherwise indeterminate obligations of “due regard” and non-interference. This entails developing common procedures for conjunction warnings, agreed best practices for rendezvous and proximity operations, minimum notification thresholds for close approaches, and clearer consultation triggers under Article IX of the Outer Space Treaty, including an agreed interpretation of what constitutes potentially harmful interference. It further entails codifying a durable prohibition, or at minimum a universal moratorium, on destructive direct-ascent anti-satellite testing, taking General Assembly Resolution 77/41 as the political baseline and negotiating attendant verification practices around space situational awareness (SSA) data-sharing and debris tracking.

The regime should also establish an incident notification and assistance mechanism modelled on the safety logic of aviation and maritime governance, providing for the standardized reporting of interference events, anomalous maneuvers, on-orbit breakups, losses of control, and cyber incidents affecting command and control. Critical humanitarian space services warrant particular protection: the recommendations advanced by the International Committee of the Red Cross can be translated into responsible-behaviour commitments requiring restraint and precaution with respect to satellite services that support humanitarian relief and emergency response. Cybersecurity, in turn, should be treated as a condition of authorization and continuing supervision under the State-responsibility logic of Article VI, drawing on frameworks such as Space Policy Directive 5 to establish common minimum controls encompassing secure update paths, network segmentation, key management, incident response, and resilience testing. Finally, the regime should embed verification by design through SSA and registration discipline, strengthening the completeness and timeliness of registration and promoting interoperable SSA sharing; the identification function of the Registration Convention constitutes a foundational compliance layer for any meaningful deterrence regime.

8. CONCLUSION

The evolution of space law has reached a turning point, shifting from the research-centric focus of the Cold War to a security and economy-centric framework for the 21st century. For students of international law, three takeaways are paramount: 1) The Policy Shift: Governance is moving from R&D promotion toward complex traffic management and the regulation of the space economy. 2) The Necessity of Resilience: Legal frameworks must incentivize the ability of space systems to recover functions quickly after damage, moving beyond simple defense to “survivability.” 3) Domestic Implementation: International treaties require domestic teeth. We see this in Korea’s 4th Basic Plan for Space Development Promotion, which underscores the need for a domestic Space Security Act to fulfill treaty obligations and protect national assets. Ultimately, we must defend the vision of outer space as the “Common Heritage of Mankind.” It is our shared duty to ensure this domain remains a sanctuary for peaceful cooperation rather than a theater for conflict.