The Legality of Targeting Dual-Use Satellites under the Jus ad Bellum and the Jus in Bello

Table of Contents

LIST OF ABBREVIATIONS

TABLE OF CASES AND ADVISORY OPINIONS

TABLE OF US LEGISLATION

TABLE OF TREATIES

UNITED NATIONS DOCUMENTS

EUROPEAN UNION DOCUMENTS

1. INTRODUCTION

2. DUAL-USE SATELLITES, SPACE DEBRIS, AND ASAT WEAPONS – A FACTUAL OVERVIEW
2.1. DUAL - USE SATELLITES
2.2. THE ISSUE OF SPACE DEBRIS
2.3. ANTI - SATELLIT E WEAPONS

3. JUSAD BELLUM SPATIALIS – PROHIBITED USES OF FORCE IN OUTER SPACE
3.1. THE INTERNATIONAL OUTER SPACE LEGAL FRAMEWORK
3.2. THE UNCHARTER AND CUSTOMARY INTERNATIONAL LAW
3.3. INTERMEDIATE CONCLUSIONS

4. JUSINBELLO SPATIALIS – THE LEGITIMATE CONDUCT OF HOSTILITIES IN OUTER SPACE
4.1. LACK OF OUTER SPACE - SPECIFIC REGULATION
4.2. APPLICATION OF THE CURRENT IHL- FRAMEWORK TO OUTER SPACE ARMED CONFLICTS
4.3. THE NOTION OF “ ATTACK ” IN OUTER SPACE MILITARY OPERATIONS
4.4. DUAL - USE SATELLITES AS LEGITIMATE MILITARY OBJECTIVES
4.5. THE PRINCIPLES OF PROPORTIONALITY AND PRECAUTION AS TARGETING RESTRICTIONS
4.6. PROHIBITED MEANS AND METHODS OF SPACE WARFARE
4.6.1. Outer space-specific prohibitions
4.6.2. Space debris-causing means and methods

5. CONCLUSION AND OUTLOOK

Abstract

The ever-increasing reliance of modern societies and modern militaries on space assets, including dual-use satellites, also increases the likelihood that these systems will be targeted in future outer space conflicts, with potentially devastating humanitarian consequences. This thesis assesses the legality of targeting dual-use satellites under the jus ad bellum and the jus in bello spatialis. Under the jus ad bellum spatialis, consisting of the international outer space legal framework, the UN Charter and customary international law, States are prohibited from using force against other States’ space objects, such as dual-use satellites. In case of armed conflict, the jus in bello spatialis regulates the manner in which dual-use satellites may be legitimately targeted in outer space. The targeting of dual-use satellites poses several unique challenges. Due to their dual-use purpose, dual-use satellites generally qualify as legitimate military objectives which can be lawfully targeted. This is cause for great humanitarian concern. Many satellites serve dual-use purposes and their disruption can have significant effects for the civilian population. The destruction of a dual-use satellite and the resulting space debris can have disastrous consequences for the highly fragile space environment. At the same time, the potential military advantage gained from an attack on a dual-use satellite might be so great that its disruption or destruction can still be considered to be proportionate to the anticipated collateral damage. Further challenging is that due to the lacking international registration regime and the confidential nature of security- related space activities, it is often difficult to make adequate proportionality and precautions assessments. The general prohibitions regarding means and methods of warfare also apply during outer space armed conflict and consequently, the use of kinetic ASAT weapons to target dual-use satellites is prohibited because their effects indiscriminately affect other (civilian) space objects and because they cause widespread, long-term and severe damage to the outer space environment.

List of abbreviations

Abbildung in dieser Leseprobe nicht enthalten

Table of cases and advisory opinions

- Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America) [1986] ICJ Rep 14
- Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion [1996] ICJ Rep 226

Table of US legislation

- Space Policy Directive-4 (2019)

Table of treaties

- Agreement Governing the Activities of States on the Moon and Other Celestial Bodies (signed 18 December 1979, entered into force 11 July 1984) 1363 UNTS 3
- Charter of the United Nations (signed 26 June 1945, entered into force 24 October 1945) 1 UNTS XVI
- Convention on International Civil Aviation (signed 7 December 1944, entered into force 4 April 1947) 15 UNTS 295
- Convention on Registration of Objects Launched into Outer Space (signed 12 November 1974, entered into force 15 September 1976) 1023 UNTS 15
- Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques (signed 10 December 1976, entered into force 5 October 1978) 1108 UNTS 151
- Geneva Convention Relative to the Protection of Civilian Persons in Time of War, (signed 12 August 1949, entered into force 21 October 1950) 75 UNTS 287
- Protocol Additional to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of International Armed Conflicts (Protocol I) (signed 12 August 1977, entered into force 7 December 1978) 1125 UNTS 3
- The Antarctic Treaty (signed 1 December 1959, entered into force 23 June 1961) 402 UNTS 71
- Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Underwater (signed 5 August 1963, entered into force 10 October 1963) 480 UNTS 43
- Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies (signed 27 January 1967, entered into force 10 October 1967) 610 UNTS 205
- United Nations Convention on the Law of the Sea (signed 10 December 1982, entered into force 16 November 1994) 1833 UNTS 3
- Vienna Convention on the Law of Treaties (signed 23 May 1969, entered into force 27 January 1980) 1155 UNTS 331

United Nations Documents

- UNGA Resolution 1962 (XVIII) (13 December 1963) UN Doc A/RES/1962(XVIII)
- UN COPUOS Inter-Agency Space Debris Coordination Committee space debris mitigation guidelines (29 November 2002) UN Doc A/AC.105/C.1/L.260
- UNGA Resolution 62/217 (22 December 2007) UN Doc A/RES/62/217
- UNGA Resolution 72/250 (24 December 2017) UN Doc A/RES/72/250
- UN COPUOS Guidelines for the Long-term Sustainability of Outer Space Activities (27 June 2018) UN Doc A/AC.105/2018/CRP.20

European Union Documents

- Council of the European Union (9 December 2008) EU Doc 17175/08 ‘The space environment has fundamentally changed in the last generation; what was once peaceful and uncontested is now crowded and adversarial.’¹

Mike Pence, US Vice President

1. Introduction

Outer space as an area of growing economic, social, technological, and military concern is becoming increasingly relevant.² It has become a vital part of modern human life and bears countless possibilities of mankind’s future. Modern societies around the globe have grown to become so reliant on space-based services that they could not function without them. Moreover, the future holds a hardly imaginable use, travel and colonization of outer space that so far only science-fictionists dared to predict. The current trends of and needs for fast information exchange via satellite systems will increase exponentially in the upcoming information society, industry 4.0, and the big data revolution. At the moment everything seems possible, however it is imperative that we keep space clean, accessible and peaceful in order to guarantee further prosperity and advancement of mankind.

Besides the peaceful uses of outer space, in the past being mostly about research and discovery and nowadays increasingly about commercial activities, there has always been a less obvious, but nevertheless significant military use of space, that has ever been growing over the last six decades. Like for civil society, space technologies have become indispensable for modern militaries, who highly depend on space-based services in their daily operations.³ These services include for instance navigation systems to enable precision navigation and targeting, communication systems, or space- based monitoring systems that allow for advance warnings of missile attacks, surveillance and reconnaissance. From a strategic position, space as the “fourth dimension of warfare”⁴ is considered the “ultimate high ground”⁵ by modern militaries and space technologies serve as force multipliers, enabling armed forces to be more efficient and effective.⁶ The importance of military space systems will continue to increase in the future. Correspondingly, the probability that these systems will be targeted will likewise increase.⁷ Due to the constant growth of and reliance on outer space use by both modern societies and modern militaries, space is increasingly becoming more competitive, congested, contested and even weaponised, which increases the risk of future conflicts in outer space.

The outer space arms race has only just begun.⁸ Sophisticated means and methods of space warfare to target space objects have been and still are being rapidly developed. At the same time, most space objects, including satellites, serve potential or actual dual- use purposes, meaning they (can) have both civilian and military applications.⁹ Since it is today generally accepted that the rules of the Laws of Armed Conflict (LOAC)¹⁰ are operative in outer space, problematically the legal definition of military objectives will render large parts of the outer space infrastructure a legitimate military objective that can be lawfully targeted. The only restrictions are imposed by the general rules of the UN Charter¹¹, the LOAC, and international space law. It is important to note that the humanitarian and environmental consequences for the highly space-dependent society on Earth and for the highly fragile and unique outer space environment are potentially disastrous, if satellite-based services are disrupted either due to direct military attacks or by space debris resulting from such attacks, which stays in orbit for decades and poses collision risks with other space objects. This has to be considered when targeting those dual-use space objects.

Modern societies have come to rely so heavily on space technologies that large-scale disruptions of space-based services could prove devastating to life as we know it. Space- based services have become vital to the functioning of modern societies in practically all areas of modern life, including communications, transportation, commerce, disaster prevention or food production.¹² Today, air transport, shipping, and in the future increasingly self-driving vehicles, are extremely dependent on Global Navigation Satellite Systems (GNSS). Likewise, financial services, (tele-)communication, health and emergency services, disaster prevention and mitigation, or agriculture and fishery highly rely on satellites and their reliance is ever increasing. It has been noted that these services could partially or even completely fail if the satellites on which they depend are disrupted, disabled, damaged or destroyed.¹³ Besides immense economic losses, the humanitarian effects are potentially disastrous, if safety-critical services, food production, supply of goods, communication services in remote areas or other vital services would fail.

Meanwhile, the likelihood of conflicts in and over outer space, including armed conflicts, is ever increasing. Future conflicts over space resources or geopolitical conflicts on Earth that might spill-over to space contribute to the fragility of the continued peaceful and cooperative use of outer space. The recent 2019 US Space Policy Directive-4, which orders the establishment of a US Space Force, brought the issue of potential future conflicts in outer space back on the international space and security agendas. However not only the US, but also Europe, China, Russia, and various other countries have identified space as part of their critical and their essential military infrastructure and as a potential ground for future battlefields.¹⁴ Fortunately, no hostilities have been conducted in outer space to date. Yet this also means that there is no State practice on the matter so far, but rather much legal and political uncertainty instead.

Unfortunately, the rules governing the jus ad bellum ¹⁵ and the jus in bello ¹⁶ spatialis are far from being conclusively developed and remain insufficient to appropriately tackle upcoming issues. This leaves us with the current international law frameworks regarding the use of force, the conduct of hostilities, and outer space, which urgently need to be clarified and interpreted in the context of outer space warfare. At the moment, the rules of space law found in international treaties focus almost exclusively on the peaceful uses of outer space. Yet, as outer space conflicts are becoming more and more likely, more legal clarity regarding the jus ad bellum and the jus in bello rules is urgently required to prevent these dangerous conflicts and to adequately protect anyone potentially adversely affected.

The purpose of this thesis is to assess the legality of targeting dual-use satellites under the jus ad bellum and the jus in bello. I will analyse which of the current international rules apply and how they govern the targeting of dual-use satellites in potential future outer space conflicts. This includes the relationship between general international space law, the laws prohibiting the use of force between States, and the LOAC. It further includes the general applicability and interpretation of jus ad bellum and jus in bello rules in the atypical, res communis environment that is outer space.

“Targeting” in this context is to be understood as disrupting, disabling, damaging, or destroying an adversary’s satellite with the aim of temporarily or permanently negating him its use. Dual-use refers to the fact that the satellite (can potentially) serve both military and civilian purposes. This thesis only focuses on military operations in outer space, however it is important to note that military operations against ground-based components of space systems can have similar or even equal effects to attacks against space-based components.

In the beginning, I will briefly review the factual background necessary for my legal analysis. This includes an overview over dual-use satellites, the problem of space debris, and anti-satellite (ASAT) weapons. This serves the purpose of both introducing the reader to the subject and is later important to underline my arguments when it comes to assessing the legality (or illegality) of targeting dual-use satellites.

Subsequently, I will analyse the international outer space legal framework (consisting of the outer space treaties, the UN Charter and customary international law), which focuses primarily on the peaceful uses of outer space. Together with the prohibition of the use of force found in the UN Charter, I will see whether and how they limit any forceful measures in outer space (like targeting dual-use satellites).

Afterwards, I will turn to the restrictions and prohibitions posed by IHL when it comes to outer space armed conflicts and the targeting of dual-use satellites. Relevant issues include the application of the LOAC to outer space armed conflicts, the notion of “attack” (distinguishing it from mere “acts of inconvenience”), and the principle of distinction in the context of dual-use objects under IHL and specifically in the outer space context, as large parts of the outer space infrastructure, including satellites, are dual-use objects and thus can be lawfully targeted. Restrictions on the legitimate targeting are imposed by the principles of proportionality and precaution. The potential disastrous immediate environmental effects of outer space military operations for the space environment through the creation of space debris and the potential devastating wider effects for civilians on Earth through the outage of essential (dual-use) satellite- based services must be weighed against the admittedly great potential military advantages that result from neutralising an adversary’s (dual-use) satellite. These potential adverse effects have to be avoided and minimized as much as possible. Lastly, the prohibited means and methods of space warfare will be analysed. It will be shown that the general prohibitions under the LOAC also apply in outer space and that the use of debris-causing ASAT weapons is prohibited in outer space armed conflict because their effects indiscriminately affect other (civilian) space objects and because they cause widespread, long-term and severe damage to the space environment.

2. Dual-use satellites, space debris, and ASAT weapons – a factual overview

In the following subsections, a brief overview over dual-use satellites, space debris, and ASAT weapons will be provided. This background information is necessary for the subsequent legal analysis of the legality of targeting dual-use satellites under the jus ad bellum and the jus in bello in sections 3. and 4.

2.1. Dual-use satellites

Usable¹⁷ (artificial) satellites are man-made space objects¹⁸ that are placed in one of the Earth’s orbits. They usually consist of a power system and functions to send, receive, and collect data and information.¹⁹ Dual-use refers to the fact that these satellites (actually or potentially) simultaneously execute both military and civilian functions.²⁰

It is estimated for example that more than half of all American and Russian (civilian and military) satellites currently in orbit serve or have served military purposes.²¹

‘There is a close affinity between civilian and military space technologies’²² and it has been noted that almost every man-made space object (not only satellites), either directly or by adaptation, has a (potential) military application. According to Scheffran²³, ‘[s]pace technologies have an inherent dual-use capability’. It is therefore usually difficult if not impossible to classify an unknown man-made space object as either civilian or military.²⁴ Furthermore, the difficulty to properly distinguish between civilian and military satellites is also due to the fact that much information regarding the purposes and uses of satellites is classified or hidden by States.²⁵ Admittedly, the REG obliges all States to register their space objects and indicate their intended function with the UN Secretary-General (Art. IV (1) REG). A civilian space object should therefore be clearly identifiable as having civilian status. In reality however, it is rather difficult to assess whether space objects have military (including dual-use) or civilian status. This is because the REG does not differentiate between military and civilian space objects²⁶ and States are not obliged to disclose (potential) military applications. Furthermore, the information provided can be very general²⁷ and space objects must only be registered as soon as is practicable (which can also occur post-mission). This makes it very difficult to identify a (potential) military satellite via the UN registration during its mission.²⁸

Because it is more economically viable to develop satellites for dual-use purposes rather than confining them to either a civilian or military purpose, States and civilian operators increasingly rely on dual-use satellites in their outer space operations.²⁹ Though there are satellites exclusively used by the military, the lines between purely civilian and military satellites become increasingly blurry and dual-use satellites are more and more used.³⁰ Modern militaries, (like the US in particular) not only provide civilian services via their military satellites, but also frequently rely on private commercial satellite operators in their operations.³¹ It is estimated for example that about 80% of all US governmental satellite communications traffic, including that for the US military, is carried out via commercial satellite communications systems.³²

As stated in the introduction, both modern societies and modern militaries have become heavily dependent on satellite-based services. The applications of satellites are manifold,³³ but they are generally used for navigation³⁴, communication³⁵, and remote sensing³⁶. These applications are being offered and used (often simultaneously, thus making the satellites dual-use) by both civilian and military providers and users.³⁷

Civilian applications include for instance air or shipping navigation, navigation in the areas of agriculture or fishery, television broadcasting and enabling long-distance communication, or weather prediction and resource exploration.³⁸ These civilian satellite-services are often mirrored by military uses. For modern militaries, satellites serve as force multipliers and are an essential part in the global C3I-systems (Command, Control, Communication, and Intelligence). They drastically increase the efficiency and effectiveness of the armed forces utilising them. Military satellite-based services include for example navigation systems to enable precision navigation and targeting, communication systems to interlink different military units and enable interconnecting weapons systems, space-based monitoring systems that allow advance warnings of missile attacks, or systems to gather surveillance and reconnaissance data. That is why space-based assets – satellites in particular – have become deeply integrated into modern warfare.³⁹

Space technologies and their applications have become a crucial part of modern human life and the dependency on satellites is ever increasing.⁴⁰ Satellites collect and almost instantly broadcast large amounts of data worldwide and modern societies depend on it. However, if satellite-based services are disrupted, disabled, damaged, or destroyed for example due to direct military attacks or by space-debris (see subsections 2.2. and 2.3.), the consequences for the highly and ever more space-dependent societies are potentially disastrous.⁴¹

It has been noted that any failure of the GNSS for instance could lead to lead to a partial or complete failure of vital civilian services such as food supply, weather prediction and disaster prevention, emergency services, control systems for energy grids and water supply, or the financial system.⁴² The effects of small-scale satellite failures in the past have already lead to major economic losses⁴³ and potential financial losses due to a complete outage of the GNSS are estimated to be one billion dollars per day for the US alone.⁴⁴ Large-scale failures, for example due to direct military attacks on satellites, are predicted to likely be devastating⁴⁵ for the civilian population on Earth.⁴⁶

2.2. The issue of space debris

Space debris⁴⁷ is one of the most prevalent issues in outer space. It is defined as ‘all man-made objects, including fragments and elements thereof, in Earth orbit or re- entering the atmosphere, that are non-functional.’⁴⁸ Space is a very distinct fragile and challenging environment. Time and time again, international fora⁴⁹ and experts⁵⁰ have noted that outer space is becoming more and more congested⁵¹, contested⁵² and competitive⁵³. There are currently more than 900,000⁵⁴ debris objects larger than 1 cm in orbit, of which primarily the US military (and then other space surveillance networks (SSN)) is only able to track approximately 23,000 objects larger than 10 cm at the moment⁵⁵. These objects pose a collision risk to the about 1,950⁵⁶ operating satellites (military and civilian likewise) and manned systems (of which only a few have manoeuvring/debris-avoidance capabilities)⁵⁷ and they dramatically increase the costs of space operations.⁵⁸ Particular troublesome is the situation in the crowded Low Earth Orbits (LEO), where most debris pieces are located. However due to the Earth’s drag force, objects in LEO are also faster removed in comparison to other orbits.⁵⁹ The typical velocity of these debris objects is 30,000 km per hour or more, making the kinetic force of these objects enormous. There have been already several confirmed, unintentional collisions between functional satellites and space debris which have either damaged or destroyed the involved space objects and thereby created thousands of new pieces of debris posing new collision threats to other space objects.⁶⁰ The untimely termination of an active satellite’s mission can cost the owner (or insurance providers) potentially millions of dollars in losses.⁶¹ Even though some objects are gradually (usually over decades) removed from orbit due to the drag force⁶², the whole space system is bound to collapse in the near future due to orbital debris if countermeasures are not taken and if new debris is constantly added. The growing number of space debris poses one of the biggest threats to the continued peaceful and safe use of outer space.⁶³

Physically damaging or destroying space objects is likely to generate space debris, which in turn can damage or destroy other space objects like satellites, many of which are essential for society on Earth (see subsection 2.1.). The US and Russia have conducted dozens of ASAT tests in space since the 1960s, some of which created long- term orbital debris.⁶⁴ The consequences of the 2007 Chinese test attack on one of its own satellites generated at least 3,000 trackable⁶⁵ pieces of harmful debris and demonstrated the potentially grave effects of outer space warfare on the space environment and for other space objects. The debris will continue to pose a collision risk to other space objects for decades to come.⁶⁶ In 2012, the International Space Station (ISS) had to perform an evasive manoeuvre in order to avoid potentially fatal collisions with the debris cloud resulting from that 2007 test attack.⁶⁷ In 2008, the US likewise destroyed one of its own defunct spy satellites via an ASAT weapon (ostensibly to prevent its payload of frozen fuel from causing harm on Earth⁶⁸ ). However, since the satellite was destroyed at a lower altitude, the resulting debris was destroyed upon re-entry into the Earth’s atmosphere shortly after. In 2009, the collision between a Russian military and a US commercial satellite created around 2,000 pieces of potentially harmful debris which are still being tracked.⁶⁹ Like the Chinese ASAT test, the resulting debris will remain in LEO for decades and poses a long-term threat to other space objects.⁷⁰

Generally, while considered antisocial, the creation of long-lasting space debris is not illegal per se under international law.⁷¹ The international outer space legal framework leaves much uncertainty regarding permitted uses and activities in space (see subsection 3.1.) and so far, no binding legal instrument prohibiting the creation of space debris or the use of debris-creating weapons has been adopted. At the moment, it does not appear politically feasible that such an instrument will follow soon. A customary rule prohibiting the creation of orbital debris has likewise not developed (yet).⁷² This could change in the future. Several spacefaring nations have taken active measures to slow the growth of orbital debris or even started to engage in active debris removal missions.⁷³ Furthermore, the spirit of the international outer space framework that focuses on the peaceful and cooperative use of outer space, together with several initiatives such as the Group of Governmental Experts (GGE) process⁷⁴ or the 2014 Draft International Code of Conduct for Outer Space Activities⁷⁵, and voluntary, non- binding instruments, such as the 2007 Space Debris Mitigation Guidelines⁷⁶ or the UN COPUOS Long-term Sustainability Guidelines⁷⁷, might be evidence that such a customary rule is in the making. Such a custom could develop very quickly. Cheng⁷⁸ once famously noted the possibility of ‘instant custom’ in international space law and due to the lack of new binding instruments⁷⁹, soft law has been increasingly utilised to regulate space activities and will likely play an even more important role in regulating space activities in the future.⁸⁰

This is further underlined by events earlier this year (2019), when India likewise tested its ASAT capabilities by destroying one of its own satellites and thus created potentially harmful debris. Afterwards, it was eager to stress that the resulting debris was only minimal and in a LEO, from which it would rapidly decay after re-entering the Earth’s atmosphere. Considering India’s statements in the context of the upset international reactions regarding India’s ASAT test and the resulting debris, this further shows that an international customary rule prohibiting such tests and uses of ASAT weapons might Mutschler, ‘Security Cooperation in Space and International Relations Theory’ in Schrogl and others (n 3) 43-48. be developing. It is definitely needed to prevent further contrary, dangerous State practice from taking form and is currently being discussed in various fora.⁸¹

At the moment, it appears that space debris will further increase over the next years or even decades as it is, since the international efforts to combat the issue are very slow. However, further testing and use of ASAT weapons would drastically worsen the current situation in outer space, with potentially devastating long-term effects for its peaceful and beneficial use. Increasing the number of debris in space will pose an uncontrollable threat to all active satellites in orbit – both military and civilian.

2.3. Anti-satellite weapons

The growing use of and reliance on space assets by modern societies and modern militaries has led many countries⁸² to enhance their counterspace capabilities to gain a strategic advantage over their rival powers. “Counterspace” or “space control” is ‘the set of capabilities or techniques that are used to gain space superiority.’⁸³ ‘Space superiority is the ability to use space for one’s own purposes while denying it to an adversary.’⁸⁴ Counterspace capabilities consist of both offensive and defensive elements. Defensive elements serve the purpose of protecting space assets from attack, while offensive elements aim at denying the adversary the use of its space assets. ASAT weapons (to target the adversary’s satellites specifically) fall in the latter category and are being rapidly developed and are becoming more and more sophisticated.⁸⁵

There are five categories of ASAT weapons: direct-ascent weapons⁸⁶, co-orbital weapons⁸⁷, electronic means of warfare⁸⁸, directed energy weapons⁸⁹, and cyber weapons⁹⁰. An important distinction is to be made between kinetic (i.e. destructive) and non-kinetic (usually non-physically-destructive) means of outer space warfare, which has consequences for the creation of orbital debris. Apart from the potentially non- functional satellite after an ASAT attack, such debris is not created by non-kinetic means of space warfare. However, satellites are more vulnerable to kinetic means. The distinction between destructive and non-destructive capabilities can also affect the extent and duration of a satellite’s damage and disruption postattack (ranging from permanent destruction to only temporary interferences).⁹¹

China’s aforementioned ASAT test is a well-known example of employing a kinetic direct-ascent weapon and the effects in outer space through the creation of dangerous orbital debris that are likely to cause harmful interference with other (military and civilian) space operations are well-documented (see subsection 2.2.).⁹² Fortunately, there have been only tests and demonstrations of kinetic ASAT capabilities by States against their own space assets and dedicated ASAT weapons have not been placed into orbit to date (as far as is known). By contrast, non-kinetic ASAT capabilities (for example cyber weapons) are likely already actively used in today’s military operations.⁹³

The advent of ASAT weapons and the corresponding increased threat of warfare in space increases the risks of space operations and will likely also increase the already high costs of entry for civil and commercial space operators.⁹⁴ It gravely endangers the further peaceful use and exploration of outer space for the benefit of mankind. However generally, the testing, deployment and use of ASAT weapons is not expressly prohibited under international law, although there have been various unsuccessful attempts to ban outer space (including ASAT) weapons.⁹⁵ The legality of targeting (dual-use) satellites will now be discussed in the following sections.

3. Jus ad bellum spatialis – Prohibited uses of force in outer space

The jus ad bellum is the international regime that governs inter-State force and is a system to prevent inter-State conflicts.⁹⁶ In this section, the legality of using force in outer space against other State’s space objects (which includes dual-use satellites) will be assessed. In the following, relevant rules of the international outer space legal framework, the UN Charter, and customary international law in the context of the prohibition of the use of force between States will therefore be analysed.

Lacking State practice when it comes to uses of force in outer space and lacking space- specific regulation complicates this assessment. The rules of the international outer space legal framework focus almost exclusively on the peaceful uses of space; the rules of the UN Charter⁹⁷ are very general and customary international law has not yet sufficiently developed to conclusively assess to what extent States are constraint by international law when it comes to using force in outer space against other State’s space objects, such as dual-use satellites. Still, there are some rules of international space law that restrict the use of force in outer space and the general jus ad bellum rules are also applicable. Art. 31 (1) of the Vienna Convention on the Law of Treaties⁹⁸ provides guidance on how to interpret treaty norms in a new context and states that ‘[a] Treaty shall be interpreted in good faith in accordance with the ordinary meaning to be given to the terms of the treaty in their context and in the light of its object and purpose.’ This thesis will subsequently rely on this provision when interpreting general jus ad bellum (and later jus in bello) provisions and applying them in the context of outer space.

3.1. The international outer space legal framework

The framework of international space law regulating outer space activities consists of five multilateral space treaties at the core⁹⁹, which were concluded under the auspices of the UN, and nowadays also of various soft law agreements, such as United Nations General Assembly (UNGA) resolutions, transparency and confidence-building measures, and policy guidelines.¹⁰⁰ Many of the space treaties’ provisions have customary international law status today¹⁰¹ and generally, custom and soft law instruments are of particular importance for regulating outer space activities.¹⁰²

Unfortunately, the current international outer space legal framework remains insufficient to appropriately regulate uses of force in outer space and does not suffice to ensure the continuing sustainability, peacefulness, and security of outer space. The UN and the international community have been unable to adequately respond to the technological development of ASAT capabilities and to adjust the current international law framework accordingly in a binding fashion. Various initiatives that sought to specifically address and prohibit the placement of weapons in space or the use of force against space objects (such as dual-use satellites) have been unsuccessful. Worth mentioning are the longstanding disarmament efforts by the UN Conference on Disarmament (UNCD) to conclude a treaty on the Prevention of an Arms Race in Outer Space (PAROS), and also the drafting and negotiation process of the Draft Treaty on the Prevention of the Placement of Weapons in Outer Space, the Threat or Use of Force against Space Objects. The latter has been proposed and submitted to the UNCD by China and Russia in 2002, 2008, and 2014, but was never adopted, mainly due to the US’ opposition.¹⁰³ This leaves us with the limited current rules to regulate the jus ad bellum spatialis and to ensure that outer space will be maintained exclusively for peaceful purposes.

It is still contested today where the application of international space law begins, as the delimitation question between airspace and outer space has not been conclusively answered. This has potential implications for the legality of using force in space (see subsection 3.2.)¹⁰⁴. Different from airspace, which is under the sovereign control of the subjacent State¹⁰⁵, outer space as an extra-territorial regime and a global commons (Arts. I, II Outer Space Treaty¹⁰⁶ ) is not under sovereign control. Several proposals have been made in the past with regard to the air-space boundary. At 12 km above the sea lies the re-entry threshold for space systems. At 18 km, the upper limit of civil aviation is reached and at 50 km the upper limit of atmospheric buoyancy. At 100 km (the so- called Kármán Line), aircraft aerodynamic controls become ineffective. At 160 km is the lowest practical operating orbit for satellites. At the moment, there is a global tendency towards the Kármán Line. However, for political reasons, it remains controversial.¹⁰⁷ The US in particular resist any legal delimitation of outer space to avoid restrictions on their high-altitude military activities.¹⁰⁸ In any case, since 160 km is the lowest practical operating orbit for satellites, this thesis premises that (dual-use) satellites are located in the extra-territorial outer space.

The UN outer space treaties focus almost exclusively on the peaceful uses of space and it has been questioned in the past whether international space law even applies in situations of inter-State armed confrontations.¹⁰⁹ However, the treaties do not explicitly exclude such situations and furthermore, customary international law prohibiting the use of force in outer space has started to develop.

First and foremost, outer space is to be used for peaceful purposes,¹¹⁰ despite the past and present military uses of space.¹¹¹ The central international agreement governing the use of outer space is the OST. Paras. 2 and 4 of the OST preamble first mention the principle of the ‘peaceful purposes’ of outer space use,¹¹² which is considered to be customary law.¹¹³ The term appears in almost all UN documents relating to outer space and was adopted from the Antarctic Treaty¹¹⁴ and later repeated again in the UN Convention on the Law of the Sea¹¹⁵. Since the term appears in both treaties, they have often been referenced when interpreting the term regarding outer space. Since the early uses of space, the question of whether “peaceful” means “non-military” or “non- aggressive” is a recurring point of contention, especially with regard to the rapid development of sophisticated means and methods of space warfare (see subsection 2.3.). More widely accepted today is that the term “peaceful” is to be understood as “non- aggressive” and that the OST only prohibits certain military activities (like placing WMD in space, Art. IV OST).¹¹⁶ It has also been pointed out that “non-military” would not correspond with State practice on this matter, as many space assets are in fact military or dual-use¹¹⁷ and since almost any technical space device can potentially be used by armed forces (see subsection 2.1.).

According to Art. I OST, the exploration and use of outer space shall be ‘carried out for the benefit and in the interests of all countries’. Furthermore, it states that space ‘shall be free for exploration and use by all States without discrimination of any kind, on a basis of equality and in accordance with international law’. The last obligation is further reiterated by Art. III OST, according to which outer space activities are to be carried out in accordance with international law, the UN Charter¹¹⁸, in the interest of maintaining international peace and security and promoting international cooperation and understanding.¹¹⁹ These provisions further underline the omnipresent peaceful purposes principle and limit the use of force in outer space (for example against other States’ space objects, such as dual-use satellites).¹²⁰ The UN Charter explicitly prohibits uses of force between States, except in cases of self-defence or if authorised by the UN Security Council acting under Chapter VII of the UN Charter (see subsection 3.2.).¹²¹

Furthermore, it would be difficult to reconcile such illegal uses of force with the ‘peaceful purposes’ (meaning “non-aggressive”) principle or the other provisions of Arts. I and III OST.

In addition, it is worth mentioning that the OST also calls explicitly for international co-operation (Arts. IX and XII) in the conduct of outer space activities. Art. IX OST further specifically obliges State Parties to conduct outer space exploration in a manner as to avoid harmful contamination of the Moon and other celestial bodies. It also states that if a State Party to the Treaty has reason to believe that an activity by it would cause potentially harmful interference with activities of other State Parties in the peaceful exploration and use of outer space, it shall undertake appropriate international consultations before proceeding with that activity. Goh¹²² argues that this requires that an adversarial State shall be consulted beforehand of a hostile act that could potentially harmfully interfere with its space object(s) and she points out that Art. IX does not differentiate between military and civilian uses of space, thus making it also applicable to outer space military operations. Art. IX OST has been invoked in reaction to the aforementioned Chinese, American, and Indian ASAT tests that caused dangerous orbital debris (see subsection 2.2.), when these countries failed to appropriately consult prior to their tests.¹²³ Art. IX OST therefore further limits uses of force in outer space, since it is not in the spirit of international co-operation, could cause harmful interference with other States’ space objects and because space debris potentially resulting from such uses of force could harmfully contaminate the outer space environment. It is noteworthy however that the International Group of Experts involved in the second Tallinn Manual observed that because the obligation to consult has not been met by sufficient State practice, it cannot be concluded that it represents a customary international law requirement.¹²⁴

The last of the five UN space treaties, the Moon Agreement¹²⁵, has been concluded back in 1984 and has only eleven signatories. Although necessary to ensure the continuing peacefulness, sustainability and security of outer space, it is unlikely that any new binding international legal instrument further regulating outer space activities will follow soon.¹²⁶ The major space powers¹²⁷ in particular are currently unwilling or unable to agree on any new space treaty, especially with regard to regulating the use of force, the conduct of hostilities, or the weaponization of outer space.

However, customary international law prohibiting the use of force in outer space has started to form and could eventually prohibit the use of force in outer space. In its Nuclear Weapons Advisory Opinion, the International Court of Justice (ICJ) stressed the importance of soft law (UNGA resolutions in particular) for the development of customary law:

‘The Court notes that General Assembly resolutions, even if they are not binding, may sometimes have normative value. They can, in certain circumstances, provide evidence important for establishing the existence of a rule or the emergence of an opinio juris. To establish whether this is true of a given General Assembly resolution, it is necessary to look at its content and the conditions for its adoption; it is also necessary to see whether an opinio juri s exists as to its normative character. Or a series of resolutions may show the gradual evolution of the opinio juris required for the establishment of a new rule.’¹²⁸ Since the 1959, the UNGA has adopted 63 resolutions on International Co-operation in the Peaceful Uses of Outer Space and 26 resolutions on the Prevention of an Arms Race in Outer Space, almost always with overwhelming support. According to Goh¹²⁹, these resolutions can be considered as authoritative interpretations of the UN Charter in the outer space-context and contribute to the formation of customary international law regarding the prohibition of using force in outer space. Moreover, the 2017 UNGA Resolution on Further Practical Measures for the Prevention of an Arms Race in Outer Space¹³⁰ explicitly encourages all States to actively contribute to the ‘prevention of an arms race in outer space, especially the placement of weapons in outer space, as well as the use of force against space objects’. It is noteworthy that the resolution mentions ‘weapons’ in general, which is in contrast to the Art. IV OST prohibition that only covers WMD. Moreover, it mentions ‘space objects’ specifically, which would include dual-use satellites.

Customary international law is of particular importance in international space law. It fills the gaps of lacking State support for new UN space treaties and compensates for their inadequacies. Such customary space law is frequently formed through soft law agreements like UNGA resolutions. Cheng¹³¹ once famously noted the possibility of ‘instant custom’ in international space law with regard to UNGA resolutions. Furthermore, it has been pointed out that soft has played and will play a ‘crucial role’ in regulating space activities.¹³²

International space law does not explicitly prohibit the use of force against space objects, such as dual-use satellites, to date. However, it appears that a customary rule prohibiting such a use of force has started to form and might eventually fully develop. Further restrictions regarding the use of force in outer space are imposed by the general rules of the jus ad bellum, deriving from the UN Charter and customary international law.

3.2. The UN Charter and customary international law

The UN Charter¹³³ governs the lawfulness of the use of force between States in general. According to Art. 2 (4), frequently described as ‘the cornerstone of the normative and institutional system established by the Charter’¹³⁴ and a jus cogens norm¹³⁵, ‘[a]ll Members [of the UN] shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state, or in any other manner inconsistent with the Purposes of the United Nations.’ This very strict rule prohibits all forceful (meaning armed) acts between all States.¹³⁶ Any actual inter-State armed confrontation, even if only small-scale or localized, comes within the scope of the UN Charter.¹³⁷ The only accepted exceptions to the use of force prohibition are self- defence (in response to an armed attack, Art. 51 UN Charter and customary international law¹³⁸ ) and Chapter VII enforcement actions by the UN Security Council. Self-defence measures have to comply with the requirements of necessity and proportionality,¹³⁹ Chapter VII enforcement actions with jus cogens norms and the purposes and principles of the UN (Art. 24 (2) UN Charter).¹⁴⁰ It is also noteworthy that according to Art. 103 of the UN Charter, Charter obligations supersede any other international obligations, such as those of the UN space treaties.¹⁴¹ For example, obligations arising from Chapter VII enforcement actions would supersede any UN space treaty obligations restricting the use of force.

The application of the jus ad bellum rules to space might not be obvious at first. Conventionally, ‘against the territorial integrity’ is understood to refer to cross-border force.¹⁴² Yet, outer space is res communis ¹⁴³ and does not know any borders. Furthermore, space objects are technically outside the territory of any State. This might make it questionable whether the use of force in outer space is within the scope of Art. 2 (4) UN Charter. Yet, the addendum ‘or in any other manner inconsistent with the Purposes of the United Nations’ (laid down in Art. 1 of the Charter) is meant to also cover and prohibit other uses of force¹⁴⁴ and it has been convincingly argued that the UN Charter prohibition also extends to uses of force in outer space.¹⁴⁵ In addition, as stated in the previous subsection, Art. III OST¹⁴⁶ states that general international principles and the UN Charter are applicable to outer space. This includes the prohibition of the use of force and its exception provisions as well as further customary and jus cogens rules.¹⁴⁷ Furthermore, launching States¹⁴⁸ still retain sovereignty over their space objects (such as dual-use satellites) by exercising ‘jurisdiction and control’ (Art. VIII OST¹⁴⁹ and Art. II REG¹⁵⁰ ).¹⁵¹ This is similar to maritime law and the concept of the ‘flag state’, which also ‘shall exercise jurisdiction and control […] over ships flying its flag’ (Art. 94 UNCLOS¹⁵² ). In the Nicaragua case, the ICJ has held that the ‘principle of respect for State sovereignty […] is […] closely linked with the [principle] of the prohibition of the use of force’.¹⁵³ The fact that dual-use satellites remain under the sovereign control of their respective launching States further underlines that a use of force against another State’s dual-use satellite is a use of force against that State.

In the Nuclear Weapons Advisory Opinion by the ICJ, the Court stated that the prohibition of the use of force applies to ‘any use of force, regardless of the weapons employed.’¹⁵⁴ Therefore, the use of ASAT weapons against another State’s space objects (such as dual-use satellites) comes within the ambit of Art. 2 (4) of the UN Charter and constitutes a use of force. This also includes ASAT cyber weapons, apart from minor (non-damaging or non-destructive) disruptions which do not amount to a use of force. According to Rule 69 of the second Tallinn Manual, ‘[a] cyber operation constitutes a use of force when its scale and effects are comparable to non-cyber operations rising to a level of a use of force.’¹⁵⁵

It can therefore be concluded that the current jus ad bellum rules are also applicable in outer space and that they generally limit and prohibit the use force in space in the same manner as they do on Earth.¹⁵⁶ This means that the targeting of dual-use satellites, if not in self-defence or authorised by the UN Security Council acting under Chapter VII of the UN Charter, is principally illegal under international law.

3.3. Intermediate conclusions

It has now long been accepted that outer space is subject to the general framework of international law, including the jus ad bellum,¹⁵⁷ although much remains to be clarified. The resulting lack of normative clarity contains the risk that States abuse the legal gaps or act in a way that others consider unlawful. It could also alter contemporary, force- restrictive interpretations of the jus ad bellum spatialis due to converse State practice.

It has been argued above that the international outer space legal framework, the UN Charter and customary international law allow military activities in outer space, but limit and prohibit the use of force against other States’ space objects, such as dual-use satellites. International space law obliges States to use outer space cooperatively, for peaceful (meaning non-aggressive) purposes and in accordance with international law, which includes the prohibition of inter-State use of force (except for self-defence or if authorised by the UN Security Council). Furthermore, an international customary rule prohibiting the use of force against space objects has started to develop and could eventually be crucial to ensure the continuing sustainability, peacefulness, and security of outer space.

4. Jus in bello spatialis – The legitimate conduct of hostilities in outer space

The jus in bello spatialis governs the conduct of hostilities in outer space during armed conflict. It regulates the manner in which the use of force in space between belligerent parties, specifically the targeting of any person or object during armed conflict, may be legitimately applied as to limit the effects on those adversely affected by it. While armed conflict is a relatively new issue with regard to outer space and fortunately has not occurred thus far, it is a growing issue of concern amidst the outer space arms race and rising geopolitical tensions. IHL is a system to protect the victims of armed conflict and although outer space is almost uninhabited, armed conflicts in space are likely to affect civilians on Earth.

IHL consists of the so-called “Hague system” and the “Geneva system”, which in turn consist of various treaty and customary rules. According to the ICJ, the Hague and Geneva Conventions have received broad accession from States and ‘constitute intransgressible principles of international customary law.’¹⁵⁸ However, they do not contain space-specific provisions. In addition, lack of State practice with regard to outer space armed conflicts¹⁵⁹ and the confidential nature of outer space military activities further complicate the application of IHL in outer space.¹⁶⁰ Nevertheless, the rules of IHL can be applied in outer space and they govern the legitimate targeting of dual-use satellites.

4.1. Lack outer space-specific regulation

Apart from the ENMOD Convention¹⁶¹, which expressly prohibits military environmental techniques for changing the ’dynamics, composition or structure of the earth […] or of outer space’ (Art. II ENMOD), no other international agreement directly addresses the conduct of hostilities in outer space to date. Likewise, little State practice exists on the subject (although there is opinio juris ¹⁶² ), in particular with regard to the targeting of dual-use satellites. Due to lacking political will, this is not likely to change in the near future. Therefore, we have to rely on the current set of customary and treaty rules of IHL when assessing the legality of targeting dual-use satellites.

In the second Tallinn Manual, the International Group of Experts stated that ‘because State cyber practice is mostly classified and publicly available expressions of opinio juris are sparse, it is difficult to definitely identify any cyber-specific customary international law.’¹⁶³ Therefore they agreed that existing, non-cyber-specific norms of customary international law were applicable to cyber operations. To date, no State has expressly objected to this methodology and it has been convincingly argued that in the same manner, such non-specific norms of customary law can be applied to outer space operations during armed conflict.¹⁶⁴

4.2. Application of the current IHL-framework to outer space armed conflicts

As pointed out in subsection 3.1., Art. III OST¹⁶⁵ states that outer space activities are to be carried out in accordance with international law. This includes the LOAC. It is today generally accepted that IHL applies to any military operations conducted in the context of an armed conflict, including those in outer space.¹⁶⁶ Nevertheless, it is helpful to review some of the arguments to better understand why this thesis relies on IHL and certain provisions in the following subsections.

In the Nuclear Weapons Advisory Opinion, the ICJ famously affirmed that the established principles and rules of IHL apply ‘to all forms of warfare and to all kinds of weapons’, including ‘those of the past, those of the present and those of the future’.¹⁶⁷

Therefore, IHL must also govern outer space warfare and the use of ASAT weapons, and its application is triggered by the same constitutive elements as in conventional armed conflicts.

The application of IHL does not depend on whether forceful measures are lawful under the jus ad bellum.¹⁶⁸ According to Common Art. 2 of the Geneva Conventions (GC) (incorporated into AP I by its Art. 1 (3)¹⁶⁹ ), the provisions of the Conventions ‘shall apply to all cases of declared war or of any other armed conflict which may arise between two or more the High Contracting Parties, even if the state of war is not recognized by one of them.’¹⁷⁰ Furthermore, according to Common Art. 1 of the GC, ‘The High Contracting Parties undertake to respect and to ensure respect for the present Convention in all circumstances’. The lack of any limitation on the spatial application of the LOAC in the GC as well as the emphasis on ‘all cases’ and ‘all circumstances’ further indicates that IHL also governs the conduct of hostilities in outer space.

Besides being expressed in customary IHL, IHL’s targeting restrictions are primarily established by AP I¹⁷¹. The scope of AP I’s rules on the conduct of hostilities is established by Art. 49 (3). According to the article, the protocol’s provisions on the conduct of hostilities apply to land, sea, and air warfare which may affect civilians or civilian objects on land. This is however not a closed list. It has been pointed out that there is no indication that the drafters of AP I excluded outer space warfare on purpose¹⁷² and that opinio juris is such that those provisions on the conduct of hostilities in AP I which reflect customary international law also apply to outer space warfare.¹⁷³

Therefore, the provisions of AP I on the conduct of hostilities are likewise applicable to outer space armed conflicts. Because of their customary status, most of the following rules of IHL apply not only in international armed conflict, but also in non-international armed conflict.

4.3. The notion of “attack” in outer space military operations

This thesis analyses the legality of targeting dual-use satellites. As stated in the introduction, “targeting” in this context is to be understood as disrupting, disabling, damaging, or destroying an adversary’s satellite with the aim of temporarily or permanently negating him its use.

In IHL, the notion of “attack” is the concept that serves as the basis for various specific limitations and prohibitions under the LOAC, which govern the manner in which persons and objects may be legitimately targeted.¹⁷⁴ These limitations and restrictions will be discussed in the following subsections. Art. 49 (1) AP I¹⁷⁵ defines “attacks” as ‘acts of violence against the adversary, whether in offence or in defence.’

It has been convincingly argued that ‘acts of violence’ includes both kinetic and non- kinetic means and methods of space warfare, as both can have similar damaging and destructive consequences.¹⁷⁶ Similar arguments have been made with regard to cyber weapons in the second Tallinn Manual.¹⁷⁷ The use of both kinetic and non-kinetic ASAT weapons (see subsection 2.3.) is therefore limited and prohibited by the same rules of IHL.

“Attacks” are understood to be operations that cause damage or destruction to targeted objects or death or injury to persons. It remains controversial whether acts that result in consequences short of this standard, so-called “acts of inconvenience”, are likewise regulated by IHL. Such “acts of inconvenience” include operations which lead to a mere temporary loss of functionality of an object without physically damaging it (for example through jamming of radio signals or cyber means). In the same manner, certain non- destructive and non-damaging interferences with satellites by ASAT means could thus not be considered an “attack” and thereby not restricted or prohibited under IHL.¹⁷⁸

However, an overly restrictive interpretation of the notion of “attack” is difficult to reconcile with the object and purpose of IHL, which is to ensure the effective protection of those adversely affected by hostilities, lately especially civilians.¹⁷⁹ Temporary disruptions and losses of functionality of space objects (like dual-use satellites) which seriously affect the civilian population should therefore also be covered by the notion of “attack” and thus regulated by IHL.

4.4. Dual-use satellites as legitimate military objectives

The protection of civilians and civilian objects is one of the primary goals of IHL, but often difficult to ensure during armed conflict.¹⁸⁰ The principle of distinction, which is the requirement that the parties to an armed conflict distinguish at all times between civilians and civilian objects on the hand and military objectives on the other, and direct attacks only against the latter¹⁸¹, is the ‘undisputed cornerstone of IHL’.¹⁸² It is a ‘cardinal’¹⁸³, ‘intransgressible’¹⁸⁴ principle of IHL and recognized as a jus cogens norm by the ICJ.¹⁸⁵ As such, it also governs the targeting of space objects during armed conflict. Space objects which are exclusively used for civilian purposes must therefore not be made the object of a direct attack. By contrast, military space objects are not protected against direct attack.

Military objectives are those which ‘by their nature, location, purpose or use make an effective contribution to military action and whose total or partial destruction, capture or neutralization, in the circumstances ruling at the time, offers a definite military advantage.’¹⁸⁶ All objects which do not fall under this definition are protected against direct attack. In space, the legal definition of military objective presents several practical challenges.

The line between military and non-military outer space activities is ‘notoriously blurry’.¹⁸⁷ As described in subsection 2.1., large parts of the space infrastructure – including satellites – serve a (potential) dual-use purpose meaning they are (actually or potentially) used by both civilians and the military. It is today widely accepted that this qualifies dual-use objects as military objectives which can be lawfully targeted, provided they make an effective, (not just potential) contribution to military action.¹⁸⁸

This ‘effective contribution’ can even be marginal in relation to the civilian use,¹⁸⁹ which does not affect the qualification of military objective, and is to be assessed on a case-by-case basis. Generally, all types of satellites described in subsection 2.1. are capable of making such an ‘effective contribution’ and are thus not generally protected against direct attack.

Due to the lack of an effective international regime of identification or marking and because a lot of information about the functions and purposes of many space objects is intentionally hidden (see subsection 2.1.), it is often difficult to verify the legal status of a military (including dual-use) or civilian satellite and to evaluate its ‘effective contribution to military action’.¹⁹⁰ However under IHL, an attacker is under an obligation to ‘do everything feasible to verify’ that a potential target is a legitimate military objective¹⁹¹ and in case of doubt has to presume protected status¹⁹².¹⁹³ This makes the legal targeting of dual-use satellites very challenging in practice.

In view of the high dependency of modern societies on (dual-use) satellite-based services, the fact that many of these services-enabling satellites can be lawfully targeted is cause for great humanitarian concern. The only targeting restrictions are imposed by the principles of proportionality and precaution and by environmental considerations (see subsections 4.5. and 4.6.2.).¹⁹⁴

4.5. The principles of proportionality and precaution as targeting restrictions

As outlined in subsections 2.1. and 2.2., an attack on a dual-use satellite entails grave risks of significant, even devastating humanitarian consequences for the civilian population on Earth and for the outer space environment. The protection of the victims of armed conflict and ‘to regulate the conduct of hostilities based on a balance between military necessity and humanity’ is ‘THE primary aim’ [sic] of IHL.¹⁹⁵ The principle of proportionality seeks to limit the effects of attacks by balancing military and humanitarian interests.¹⁹⁶ IHL prohibits the launching of ‘an attack which may be expected to cause incidental loss of civilian life, injury to civilians, damage to civilian objects, or a combination thereof, which would be excessive in relation to the concrete and direct military advantage anticipated.’¹⁹⁷ While protected from direct attack, it remains legally accepted that in the ‘harsh reality of war’, civilian persons and objects may be incidentally affected by an attack directed at a legitimate military objective through mistaken target identification or unintended, but inevitable side effects of that attack. This is referred to as “collateral damage” and it is lawful under IHL’s principle of proportionality only if that damage is not excessive in relation to the concrete and direct¹⁹⁸ military advantage anticipated. Otherwise it is prohibited.¹⁹⁹

Besides the principle of proportionality, IHL dictates that constant care to spare the civilian population, civilians and civilian objects is to be taken during military operations, and that expected collateral damage to the civilian population and the natural environment must be considered when assessing feasible precautions in attack as to avoid, or in any event minimize, incidental civilian harm and damage to civilian objects.²⁰⁰

When it comes to the legitimate targeting of dual-use satellites, the foreseeable harmful effects (both direct²⁰¹ and indirect²⁰² ) of the attack on the civilian population and civilian objects (including the space environment) must be avoided or minimized where practicable and practically possible²⁰³, and they must be proportionate to the definite, anticipated military advantage as a whole in terms of weakening the enemy forces.²⁰⁴

The proportionality and precautions assessments are to be made in good faith²⁰⁵ and on a case-by-case basis before an attack.²⁰⁶ Like all dual-use objects²⁰⁷, dual-use satellites generally inhibit a high risk of collateral damage. Although there is a low risk of casualties directly resulting from an attack in outer space since it is vastly uninhabited, the collateral damage for the space environment through the creation of harmful debris and the indirect damage for the civilian population on Earth through the outage of essential (satellite-based) services can be quite high, even devastating (see subsections 2.1. and 2.2.). At the same time, due to the heavy dependence of modern militaries on (dual-use) satellites, the anticipated military advantage is potentially decisive and thus proportionate vis-à-vis the collateral damage. This is cause for great humanitarian concern. While the exact scope of potential humanitarian consequences following an attack on a dual-use satellites remains uncertain and is often difficult to assess, given the lack of a sufficient international registration regime, a few indicative examples will be subsequently discussed.

Disrupting a whole GNSS just to stop a military convoy from delivering food supplies might be disproportionate and contrary to the principle of precautions, considering the potential large-scale disruptions it would cause in modern-day societies, especially with regard to safety-critical civilian activities and essential civilian services (for example air traffic control or emergency services), which could likely lead to ‘incidental loss of civilian life, injury to civilians’ or similar damage. However temporarily disabling or disrupting a dual-use satellite to effectively hinder the enemy forces from communicating or using advanced weapons systems could be a proportionate (because far greater) military advantage and compatible with the principle of precaution because the adverse effects are only temporary.

Another factor to consider in the proportionality and precautions assessments could be the manner of how a dual-use satellite is being targeted. Temporary disruptions of satellite-based services (through non-kinetic ASAT weapons) have less harmful effects on the outer space environment and essential civilian services are only temporarily disabled. Damaging or destroying a dual-use satellite (through kinetic ASAT weapons) on the other hand might be more effective and reliable from a military standpoint, but the risks of creating dangerous debris and the harmful consequences for the civilian population are much graver (see subsections 2.1.-2.3.). If feasible, choosing a less crowded orbit for an attack, where the effects on other satellites are less harmful, or a LEO from which resulting debris would decay faster, could also be factored into the precautions assessment.²⁰⁸ Generally, if a belligerent party has the choice between different means and methods of space warfare, which are similarly effective in neutralising the military objective (here dual-use satellites), or between different military objectives whose neutralisation entails a similar military advantage, the principles of proportionality and precaution dictate that it has to conduct its operation in a manner which avoids collateral damage as much as possible²⁰⁹.²¹⁰ For instance, if a belligerent party wants to disrupt the enemy’s reconnaissance capabilities, but in the process has the choice between targeting a dual-use satellite or a dedicated military satellite, it should target the latter as to avoid or minimize the adverse consequences for civilians. If it has the choice between an equally effective kinetic or non-kinetic ASAT weapon, it should resort to the latter as to avoid or minimize the creation of harmful debris.

4.6. Prohibited means and methods of space warfare

The rights of belligerent parties to choose means²¹¹ and methods²¹² of warfare is not unlimited.²¹³ This also extends to the targeting of dual-use satellites. In its Nuclear Weapons Advisory Opinion, the ICJ held that ‘the established principles and rules of [IHL] appl[y] to all forms of warfare and to all kinds of weapons, [including] those of the past, […] the present and […] the future.’²¹⁴ It further held that two ‘cardinal principles’ govern the choice of the means and methods of warfare. First, States are prohibited from making ‘civilians the object of attack and must consequently never use weapons that are incapable of distinguishing between civilian and military targets.’²¹⁵

Secondly, weapons causing unnecessary suffering (and superfluous injury²¹⁶ ) are likewise prohibited.²¹⁷ The second principle is only of limited application for the targeting of dual-use satellites in space, since humans are (basically always) not directly affected by military operations in the vastly uninhabited outer space. Or to quote an emerging maxim in space security law: ‘satellites have no mothers’.²¹⁸ The first principle however certainly applies to the targeting of dual-use satellites. It prohibits ASAT weapons per se that are incapable of being targeted at a military satellite (including dual-use) only²¹⁹.²²⁰ It further prohibits ASAT weapons whose effects cannot be sufficiently limited, for example by triggering a chain of harmful, uncontrollable events.²²¹ As described in subsections 2.2. and 2.3., the effects of kinetic ASAT weapons cause uncontrollable, dangerous chain reactions of space debris (described by the “Kessler Syndrome”). Since these effects meet the requisite degree of harm by causing large clouds of dangerous debris that will uncontrollably affect civilian space objects, kinetic ASAT weapons cannot be legally used in outer space warfare to target dual-use satellites.

Further (potential) restrictions when targeting dual-use satellites are imposed by the OST²²², the Limited Test Ban Treaty²²³, and IHL’s environmental protection provisions.

4.6.1. Outer space-specific prohibitions

Despite the international efforts (outlined in sections 2. and 3.), no international instrument specifically outlawing the use of ASAT weapons has yet materialised. However, it has been argued in the past that the OST²²⁴ and the LTBT²²⁵ at least prohibit the use of WMD in outer space, which would then potentially also restrict the use of (for example nuclear) ASAT weapons. These arguments will now be reviewed.

Art. IV OST states that ‘State Parties to the Treaty undertake not to place in orbit around the Earth any objects carrying nuclear weapons or any other kind of weapons of mass destruction, install such weapons on celestial bodies, or station such weapons in outer space in any other manner.’ It is important to note that this article does not cover other types of (conventional or ASAT²²⁶ ) weapons.²²⁷ According to Lee, Art. IV OST prohibits the use of WMD in outer space.²²⁸ However, the jus in bello application of Art. IV has been convincingly questioned,²²⁹ since it does not explicitly prohibit the “use” of WMD, but rather their “placement” in outer space.²³⁰

The LTBT reiterates Art. IV OST and prohibits nuclear explosions for both testing and non-testing purposes ‘including [in] outer space’ (Art. I LTBT). Like Art. IV OST, the LTBT’s jus in bello application has been convincingly questioned. As has been pointed out, the treaty primarily focuses on the testing of nuclear weapons and thus has only peacetime application.²³¹ It follows that the use of WMD against dual-use satellites is not expressly prohibited in outer space warfare under the OST or the LTBT. Furthermore, even if applicable, both treaties are only of limited relevance when it comes to the targeting of dual-use satellites, since ASAT weapons are usually not WMD²³² and the use of WMD against space objects is thus highly unlikely. Still, if they were used, the effects for the outer space environment and other space objects could be devastating and would be hardly compatible with the principles of distinction, proportionality, and precautions.²³³

4.6.2. Space debris-causing means and methods

As stated in subsections 2.2. and 2.3., existing international law does not adequately regulate the employment of space debris-causing weapons.²³⁴ An absolute ban of these types of weapons would be required to protect the highly fragile outer space environment from orbital debris, but to date does not exist.²³⁵ Despite the extreme fragility and volatility of the space environment, where military conflicts could have catastrophic implications, efforts to prevent it from becoming another battlefield are only under way and not likely to materialise soon.²³⁶ However, there are certain restrictions imposed by IHL, which also have implications for the targeting of dual-use satellites, and they will be subsequently analysed.

According to the ICJ, ‘States must take environmental considerations into account when assessing what is necessary and proportionate in the pursuit of legitimate military objectives.’²³⁷ They have an obligation to ‘ensure that activities within their jurisdiction and control respect the environment of […] areas beyond national control’.²³⁸ As stated in subsection 3.2., launching States retain ‘jurisdiction and control’ over their respective space objects in outer space, which is (as res communis) not subject to sovereign control. It has been convincingly argued that the environmental protection provisions under IHL extend to the space environment.²³⁹

IHL prohibits the employment of means and methods of warfare which are intended or may be expected to cause widespread, long-term and severe damage to the natural environment.²⁴⁰ These three cumulative conditions²⁴¹ are potentially fulfilled when targeting (dual-use) satellites with ASAT weapons, due to the creation of orbital debris, and thus restrict the legitimate targeting of dual-use satellites.

There is no generally accepted definition of the term ‘natural environment’. Art. II ENMOD²⁴² for example refers to the ‘dynamics, composition or structure’ of the space environment. However, due to alleged lacking State practice and opinio juris, it remains disputed whether ‘natural environment’ includes the space environment.²⁴³ Although this seems unconvincing considering the language in various UN documents relating to outer space and the international efforts to combat space debris.²⁴⁴ The condition of “long-term damage” has generally been interpreted as “lasting for decades”.²⁴⁵ “Widespread and severe damage” is assessed on a case-by-case basis. In the Understandings attached to Art. I ENMOD, ‘widespread’ is defined as ‘encompassing an area on the scale of several hundred square kilometres’ and ‘severe’ as ‘serious or significant disruption or harm to human life, natural and economic resources or other assets.’

As Blount²⁴⁶ points out, these conditions are likely fulfilled when targeting satellites with debris-causing weapons. As described in subsections 2.2. and 2.3., kinetic attacks on satellites are likely to cause dangerous debris that contaminates the orbits for decades, thus the damage is ‘long-term’. Due to the vast areas of outer space affected, the damage is certainly ‘widespread’. Lastly, because space debris significantly threatens and harms economic, social, and environmental interests in space, the damage of orbital debris caused by ASAT weapons is likely to be ‘severe’. It follows that the use of kinetic ASAT weapons against dual-use satellites is prohibited.

5. Conclusion and outlook

The reliance of modern societies and modern militaries on space assets is ever increasing. This likewise increases the likelihood that these systems will be targeted in future outer space conflicts. Sophisticated means and methods of space warfare to target space objects have been and still are being rapidly developed, even though the use of force against space objects and the use of such means and methods (especially with regard to kinetic ASAT weapons) during armed conflict might not even be legal. At the same time, most space objects, including satellites, serve potential or actual dual-use purposes, meaning they (can) have both civilian and military applications. Problematically, this further increases the likelihood that space systems which serve vital services for modern societies will be targeted. The humanitarian effects of an attack on a dual-use satellite for the highly fragile and unique outer space environment, due to the creation of orbital debris, and for the highly space-dependent civilian population on Earth, due to the disruption of essential satellite-based services, can be significant, even devastating. Despite these concerns, there is neither specific regulation nor legal clarity regarding potential future conflicts in outer space, and the political will to change that is lacking.

In this thesis, I have tried to humbly contribute to the current debate regarding more legal clarity in outer space operations, by applying and interpreting the existing rules and principles of international space law, the jus ad bellum, and the jus in bello in the unique context of outer space, specifically with regard to the legality of targeting dual- use satellites.

I have reached the conclusion that the jus ad bellum spatialis, consisting of the international outer space legal framework, the UN Charter and customary international law, generally allows military activities in outer space, but limits and prohibits the use of force against other States’ space objects, such as dual-use satellites. International space law obliges States to use outer space cooperatively, for peaceful (meaning non- aggressive) purposes and in accordance with international law, which includes the prohibition of inter-State use of force (except for self-defence or if authorised by the UN Security Council). Furthermore, an international customary rule prohibiting the use of force against space objects has started to develop and could eventually be crucial to ensure the continuing sustainability, peacefulness, and security of outer space use.

In case of an armed conflict, it is today generally accepted that IHL applies to outer space military operations. The notion of “attack” in IHL is the concept that serves for various specific targeting restrictions and prohibitions that have to be interpreted in the context of outer space. The legitimate targeting of dual-use satellites poses several unique challenges.

Under the principle of distinction, dual-use satellites generally qualify as legitimate military objectives, provided they make an actual, effective contribution to military action. Problematically, this renders large parts of the space infrastructure legitimate military objectives, whose disruption or destruction due to a direct attack can have significant, even devastating consequences for the outer space environment and for the civilian population on Earth. These adverse effects be proportionate to the concrete and direct military advantage anticipated from the attack on a dual-use satellite and they have to be avoided or minimized as much as possible in the harsh realities of outer space warfare. The fact that despite the potentially significant collateral damage, the military advantage gained from an attack on a dual-use satellite might even be greater and thus proportionate, is cause for great humanitarian concern.

Further challenging is that due to the lacking international registration regime and the confidential nature of security-related space activities, it is often difficult to adequately assess the collateral damage and the effective contribution that a dual-use satellite makes to military action. Similarly, it is frequently difficult to adequately verify whether a satellite qualifies as a civilian object (which would then be protected against direct attack) or a legitimate military objective. This makes the legitimate targeting of dual- use satellites very challenging in military practice.

Dual-use satellites are targeted by ASAT weapons. Although there is no specific regulation of these types of weapons (yet) under international law, I have argued that the use of kinetic ASAT weapons is prohibited under IHL because their effects indiscriminately affect other (civilian) space objects and because they cause widespread, long-term and severe damage to the outer space environment. Nevertheless, they have been and still are being rapidly developed.

Considering the potentially devastating humanitarian consequences of outer space warfare for the space environment and for the civilian population on Earth, binding and restrictive outer space-specific regulation of the use of force against space objects and the conduct of hostilities in space and further clarification of the applicable law is urgently required. Customary international law has not yet sufficiently developed and the current international rules and principles are far too permissive to provide for an adequate protection of the outer space environment and for the highly space-dependent societies on Earth. Unfortunately, due to lacking political will, it is unlikely that sufficient regulation will follow soon. The resulting lack of normative clarity contains the risk that States abuse the legal gaps or act in a way that others consider unlawful. It could also dangerously alter contemporary, restrictive interpretations of the jus ad bellum and the jus in bello spatialis due to converse State practice.

In this regard, the current MILAMOS and WOOMERA projects are welcome and eagerly awaited initiatives. Similar to the Tallinn Manuals, the San Remo Manual, or the Harvard Manual, the international and independent groups of legal experts involved in these projects will hopefully provide for further clarification of the existing jus ad bellum and jus in bello rules and principles applicable to outer space operations soon. Otherwise, the future of the continuing peaceful, sustainable and beneficial use of outer space could be dire.

Bibliography

Books

- Ailor W, ‘Space traffic control: issues and options’ in Rathgeber W, Schrogl K-U, and Williamson R (eds), The Fair and Responsible Use of Space: An International Perspective, Studies in Space Policy vol 4 (Springer 2010)

- Ailor W, ‘Space Traffic Management’ in Kai-Uwe Schrogl and others (eds), Handbook of Space Security (Springer 2015)

- Blake D, ‘Military Strategic Use of Outer Space’ in Nasu H and McLaughlin R (eds), New Technologies and the Law of Armed Conflict (Springer 2014)

- Cheng B, Studies in International Space Law (OUP 1997)

- Dinstein Y, The Conduct of Hostilities Under the Law of International Armed Conflict, (CUP 2004)

- Freeland S, ‘The Laws of War in Outer Space’ in Schrogl K-U and others (eds), Handbook of Space Security (Springer 2015)

- Henckaerts J-M and Doswald-Beck L, Customary International Humanitarian Law (CUP 2005)

- Hitchens T, ‘Peaceful uses of outer space vs. militarization: a cost-benefit analysis’ in Rathgeber W, Schrogl K-U, and Williamson R (eds), The Fair and Responsible Use of Space: An International Perspective, Studies in Space Policy vol 4 (Springer 2010)

- Hobe S, ‘Article I’ in Hobe S, Schmidt-Tedd B, and Schrogl K-U (eds), Cologne Commentary on Space Law, Outer Space Treaty (Berliner Wissenschafts-Verlag 2017)

- Jakhu R and Freeland S, ‘Article II’ in Hobe S, Schmidt-Tedd B, and Schrogl K-U (eds), Cologne Commentary on Space Law, Outer Space Treaty (Berliner Wissenschafts-Verlag 2017)

- Lamb S, ‘Legal Limits to United Nations Security Council Powers’ in Goodwin-Gill G and Talmon S (eds), The Reality of International Law: Essays in Honour of Ian Brownlie (OUP 1999)

- Masson-Zwaan T, ‘The International Framework for Space Activities’ in Johnson C (ed), Handbook for New Actors in Space (Secure World Foundation 2017)

- Melzer N, ‘The Principle of Distinction Between Civilians and Combatants’ in Clapham A and Gaeta P (eds), The Oxford Handbook of International Law in Armed Conflict (OUP 2018)

- Mutschler M, ‘Security Cooperation in Space and International Relations Theory’ in Schrogl K-U and others (eds), Handbook of Space Security (Springer 2015)

- Pelton J, ‘Future of Military Satellite Systems’ in Pelton J, Madry S, and Camacho-Lara S (eds) Handbook of Satellite Applications (Springer 2015)

- Ribbelink O, ‘Article III’ in Hobe S, Schmidt-Tedd B, and Schrogl K-U (eds), Cologne Commentary on Space Law, Outer Space Treaty (Berliner Wissenschafts-Verlag 2017)

- Schmidt-Tedd B, Malysheva N, and Stelmakh O, ‘Article IV (Information by Each State of Registry)’ in Hobe S, Schmidt-Tedd B, and Schrogl K-U (eds), Cologne Commentary on Space Law, Rescue Agreement, Liability Convention, Registration Convention, Moon Agreement (Carl Heymanns Verlag 2013)

- Schmidt-Tedd B and Mick S, ‘Article VIII’ in Hobe S, Schmidt-Tedd B, and Schrogl K-U (eds), Cologne Commentary on Space Law, Outer Space Treaty (Berliner Wissenschafts-Verlag 2017)

- Schmitt M (ed), Tallinn Manual 2.0 on the International Law Applicable to Cyber Operations (1st edn, CUP 2017)

- Schrogl K-U and others (eds), Handbook of Space Security (Springer 2015)

- Schrogl K-U and Neumann J, ‘Article IV’ in Hobe S, Schmidt-Tedd B, and Schrogl K-U (eds), Cologne Commentary on Space Law, Outer Space Treaty (Berliner Wissenschafts-Verlag 2017)

- Sheehan M, ‘Defining Space Security’ in Kai-Uwe Schrogl and others (eds), Handbook of Space Security (Springer 2015)

- Tronchetti F, ‘Soft Law’ in Brünner C and Soucek A (eds), Outer Space in Society, Politics and Law, Studies in Space Policy vol 8 (Springer 2011)

- Venet C, ‘The political dimension’ in Brünner C and Soucek A (eds), Outer Space in Society, Politics and Law, Studies in Space Policy vol 8 (Springer 2011)

- Weeden B and Samson V (eds), Global Counterspace Capabilities: An Open Source Assessment (Secure World Foundation 2019)

- Williamson R, ‘Fairness and responsibility in space activities’ in Rathgeber W, Schrogl K-U, and Williamson R (eds), The Fair and Responsible Use of Space: An International Perspective, Studies in Space Policy vol 4 (Springer 2010)

Journal articles

- Ailor W and Krag H, ‘Space Debris and Space Safety: Looking Forward’ [2009] 62 JBIS 261

- Bernheim C, ‘United States Armed Intervention in Nicaragua and Article 2(4) of the United Nations Charter’ [1985] 11 Yale Journal of International Law 104

- Blount P, ‘Targeting in Outer Space: Legal Aspects of Operational Military Actions in Space’ [2012] Harvard National Security Journal 1

- Bourbonnière M and Lee R, ‘Legality of the Deployment of Conventional Weapons in Earth Orbit: Balancing Space Law and the Law of Armed Conflict’ [2008] 18 (5) The European Journal of International Law 874

- Cunningham P, ‘Military Payloads Hosted on Commercial Satellites’ [2015] 53 Air Command and Staff College Wright Flyer Paper

- Finch E, ‘Outer Space for “Peaceful Purposes”’ [1968] 54 (4) American Bar Association Journal 365

- Goh G, ‘Keeping the peace in outer peace: a legal framework for the prohibition of the use of force’, [2004] 20 Space Policy 259

- Hakimi M and Cogan J, ‘The Two Codes on the Use of Force’ [2016] 27 (2) The European Journal of International Law 257

- Hebert K, ‘Regulation of Space Weapons: Ensuring Stability and Continued Use of Outer Space’ [2014] 12 (1) Astropolitics 1

- Kessler D and Cour-Palais B, ‘Collision Frequency of Artificial Satellites: The Creation of a Debris Belt’ [1978] 83 (A6) Journal of Geophysical Research 2637

- Lee R, ‘Jus Ad Bellum in Outer Space: The Interrelation between Article 103 of the Charter of the United Nations and Article IV of the Outer Space Treaty’ [2002] 45 Proceedings on the Law of Outer Space 139

- Lee R, ‘The Jus Ad Bellum in Spatialis: The Exact Content and Practical Implications of the Law on the Use of Force in Outer Space’ [2003] 29 Journal of Space Law 93

- Lee R and Steele S, ‘Military Use of Satellite Communications, Remote Sensing, and Global Positioning Systems in the War on Terror’ [2014] 79 (1) Journal of Air Law and Commerce 69

- Mačák K, ‘Silent War: Applicability of the Jus in Bello to Military Space Operations’ [2018] 94 International Law Studies 1

- Maogoto J and Freeland S, ‘Space Weaponization and the United Nations Charter Regime on Force: A Thick Legal Fog or a Receding Mist?’, [2007] 41 (4) The International Lawyer 1091

- Quéguiner J-F, ‘Precautions under the law governing the conduct of hostilities’ [2006] 88 (864) International Review of the Red Cross 793

- Ruys T, ‘The Meaning of “Force” and the Boundaries of the Jus Ad Bellum: Are “Minimal” Uses of Force excluded from UN Charter Article 2(4)?’ [2014] 108 (2) AJIL 159

- Schmitt M, ‘International Law and Military Operations in Space’ [2006] 10 Max Planck Yearbook of United Nations Law 89

- Steer C, ‘Global Commons Implications of Military and Security Uses of Outer Space‘, [2017] 18 (1) Georgetown Journal of International Affairs 9

- Stephens D and Steer C, ‘Conflicts in Space: International Humanitarian Law and its Application to Space Warfare’ [2015] XL Annals of Air and Space Law 1

- West J, ‘Why the chances of conflict in outer space are going up’ [2018] 39 (4) The Ploughshares Monitor 8

Reports and studies

- O’Connor A and others, Economic Benefits of the Global Positioning System (GPS) (RTI International 2019)

- Thomas M (ed), Global Navigation Space Systems: reliances and vulnerabilities (The Royal Academy of Engineering 2011)

- US Department of Defense and Office of the Director of National Intelligence, National Security Space Strategy Unclassified Summary (2011)

Conference papers

- Ailor W and others, ‘Space Debris and the Cost of Space Operations’ (Proceedings of the Fourth IAASS Conference ‘Making Safety Matter’, Huntsville, 2010)

- ICRC, ‘International humanitarian law and the challenges of contemporary armed conflicts Report’ (32nd International Conference of the Red Cross and Red Crescent, Geneva, 2015)

- Desgagne R, ‘International Humanitarian Law in Outer Space’ (ASEAN Regional Forum Workshop on Space Security, Beijing, 2015)

Websites and blogs

- Baraniuk C, ‘GPS error caused ’12 hours of problems’ for companies’ (BBC, 4 February 2016) <https://www.bbc.co.uk/news/technology-35491962> accessed 24 July 2019

- Bender B and Klimas J, ‘Space war is coming – and the U.S. is not ready’ (Politico, 6 April 2018) <https://www.politico.com/story/2018/04/06/outer- space-war-defense-russia-china-463067> accessed 9 July 2019

- Clark C, ‘US Presses Russia, China on ASAT Tests; Space Control Spending Triples’ (Breaking Defense, 16 April 2015) <https://breakingdefense.com/2015/04/space-control-spending-triples/> accessed 6 June 2019

- Clark C, ‘Chinese ASAT Test Was ‘Successful:’ Lt. Gen. Raymond’ (Breaking Defense, 14 April 2015) <https://breakingdefense.com/2015/04/chinese-asat-test-was-successful-lt-gen- raymond/> accessed 6 June 2019

- Clark C, ‘India Anti-Satellite Strike: Less Debris Likely, Not Like China’s’ (Breaking Defense, 28 March 2019) <https://breakingdefense.com/2019/03/india-anti-satellite-strike-less-debris- likely-not-like-chinas/> accessed 6 June 2019

- De Zwart M, ‘New Technologies Symposium: Contested and Fragile – The Dual-Use Space Environment’ (OpinioJuris, 7 May 2019) <http://opiniojuris.org/2019/05/07/new-technologies-symposium-contested- and-fragile-the-dual-use-space-environment/> accessed 29 June 2019

- Erwin S, ‘Space Force discussions increasingly blur the line between military and civilian space’ (SpaceNews, 31 October 2018) <https://spacenews.com/space-force-discussions-increasingly-blur-the-line- between-military-and-civilian-space/> accessed 9 July 2019

- European Space Agency, ‘Active Debris Removal’ (ESA, 2019) <https://m.esa.int/Our_Activities/Space_Safety/Space_Debris/Active_debris_r emoval> accessed 24 July 2019

- European Space Agency, ‘Space Debris by the Numbers’ (ESA, January 2019) <http://m.esa.int/Our_Activities/Space_Safety/Space_Debris/Space_debris_by _the_numbers> accessed 28 June 2019

- Freedberg S, ‘Pentagon Reports on China’s Satellite Killers’ (Breaking Defense, 11 May 2015) <https://breakingdefense.com/2015/05/pentagon- reports-on-chinas-satellite-killers/> accessed 6 June 2019

- Hitchens T, ‘U.S. India ASAT Test React May Backfire, Experts Say’ (Breaking Defense, 3 April 2019) <https://breakingdefense.com/2019/04/u-s- india-asat-test-react-may-backfire-experts-say/> accessed 6 June 2019

- Howell E, ‘What is a Satellite?’ (space.com, 27 October 2017) <https://www.space.com/24839-satellites.html> accessed 23 July 2019

- Johnson C, ‘The UN Group of Governmental Experts on Space TCBMs’ (Secure World Foundation, April 2014) <https://swfound.org/media/109311/swf_gge_on_space_tcbms_fact_sheet_apr il_2014.pdf> accessed 6 June 2019

- Kilibarda P, ‘Space law revisited (2/3): Are weapons of mass destruction prohibited in space?’ (ICRC, 21 December 2016) <https://blogs.icrc.org/law- and-policy/2016/12/21/space-law-weapons-mass-destruction/> accessed 17 July 2019

- Kilibarda P, ‘Space law revisited: The militarization of outer space’ (ICRC, 9 March 2017) <https://medium.com/law-and-policy/space-law-revisited-the- militarization-of-outer-space-d65df7359515> accessed 6 June 2019

- Lamb H, ‘Space agencies join forces to tackle problem of small debris in low Earth orbit’ (E&T, 19 January 2018) <https://eandt.theiet.org/content/articles/2018/01/space-agencies-tackle- problem-of-small-space-debris-in-low-earth-orbit/> accessed 24 July 2019

- Martin D, ‘The Battle Above’ (CBS, 2 August 2015) <https://www.cbsnews.com/news/rare-look-at-space-command-satellite- defense-60-minutes-2/> accessed 9 July 2019

- Shah A, ‘Militarization and Weaponization of Outer Space’ (Global Issues, 21 January 2007) <http://www.globalissues.org/article/69/militarization-and- weaponization-of-outer-space> accessed 6 June 2019

- Shalal A, ‘U.S. eyes new ways to prepare and win future war in space’ (Reuters, 17 April 2015) <https://www.reuters.com/article/us-usa-military- space-future-idUSKBN0N82E820150417> accessed 6 June 2019

- Spark J, ‘ISS Dodges Chinese ASAT Debris’ (Space Safety Magazine, 30 January 2012) <http://www.spacesafetymagazine.com/news/iss-forced-dodge- chinese-asat-debris/> accessed 25 July 2019

- Stephens D, ‘The International Legal Implications of Military Space Operations: Examining the Interplay between International Humanitarian Law and the Outer Space Legal Regime’ [2018] 94 International Law Studies 75

- Stephens D, ‘Why Outer Space Matters: Dr. Dale Stephens Gives a Brief Introduction to International Humanitarian Law’ (IKRK, 7 November 2016) <http://intercrossblog.icrc.org/blog/twmzia1cp84kv2c29bi4iz6q4u03in> accessed 6 June 2019

- Tate K, ‘Space Junk Explained: How Orbital Debris Threatens Future of Spaceflight (Infographic)’ (space.com, 2 October 2013) <https://www.space.com/23039-space-junk-explained-orbital-debris- infographic.html> accessed 16 July 2019

- The White House, ‘Remarks by Vice President Pence on the Future of the U.S. Military in Space’ (whitehouse.gov, 9 August 2018) <https://www.whitehouse.gov/briefings-statements/remarks-vice-president- pence-future-u-s-military-space/> accessed 1 July 2019

- United Nations, ‘Outer Space Increasingly ‘Congested, Contested and Competitive’, First Committee Told, as Speakers Urge Legally Binding Document to Prevent Its Militarization’ (UN, 25 October 2013) <https://www.un.org/press/en/2013/gadis3487.doc.htm> accessed 28 June 2019

- United Nations, ‘Raising Alarm over Possible Space Wars, First Committee Delegates Explore Ways to Build New Order for Preventing Celestial Conflict, Confrontation’ (UN, 24 October 2018) <https://www.un.org/press/en/2018/gadis3609.doc.htm> accessed 10 July 2019

- United Nations, ‘Stronger Rules Must Guarantee Outer Space Remains Conflict-Free, First Committee Delegates Stress, Calling for New Laws to Hold Perpetrators Accountable’ (UN, 17 October 2017) <https://www.un.org/press/en/2017/gadis3583.doc.htm> accessed 10 July 2019

- Voosen P, ‘Outer space may have just gotten a bit closer’ (ScienceMag, 24 July 2018) <https://www.sciencemag.org/news/2018/07/outer-space-may- have-just-gotten-bit-closer> accessed 28 July 2019

- Weeden B, ‘Anti-Satellite Tests in Space – The Case of China’ (Secure World Foundation, 16 August 2013) <https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&c ad=rja&uact=8&ved=2ahUKEwi5icDvjavjAhVHZcAKHflfDpcQFjAAegQIA BAC&url=https%3A%2F%2Fswfound.org%2Fmedia%2F115643%2Fchina_a sat_testing_fact_sheet_aug_2013.pdf&usg=AOvVaw0e3o7Vcoz98qLN5512C ivV> accessed 10 July 2019

- Weeden B, ‘Why Outer Space Matters: Brian Weeden on Natural and Human- generated Threats on Satellites’ (IKRK, 24 October 2016) <http://intercrossblog.icrc.org/blog/why-outer-space-matters-brian-weeden-on- natural-and-human-generated-threats-on-satellites> accessed 6 June 2019

- Wilson K, ‘Why Outer Space Matters: Krystal Wilson on Humanitarian Uses of Space’ (IKRK, 18 October 2016) <http://intercrossblog.icrc.org/blog/why- outer-space-matters-krystal-wilson-on-humanitarian-uses-of-space> accessed 16 July 2019

[...]

---

¹ The White House, ‘Remarks by Vice President Pence on the Future of the U.S. Military in Space’ (wh itehouse.gov, 9 August 2018) <https://www.whitehouse.gov/briefings-statements/remarks-vice- president-pence-future-u-s-military-space/> accessed 1 July 2019.

² Christophe Venet, ‘The political dimension’ in Christian Brünner and Alexander Soucek (eds), Outer Spac e in Society, Politics and Law, Studies in Space Policy vol 8 (Springer 2011) 73-90.

³ Kai-Uwe Schrogl and others (eds), Handboo k of Space Secu rity (Springer 2015) 521-716; Cassandra Steer, ‘Global Commons Implications of Military and Security Uses of Outer Space‘, [2017] 18 (1) Georgetown Journal of International Affairs 9.

⁴ After land, sea, and airspace.

⁵ Located above all three conventional dimensions of warfare.

⁶ Anup Shah, ‘Militarization and Weaponization of Outer Space’ (Global Issues, 21 January 2007) <http://www.globalissues.org/article/69/militarization-and-weaponization-of-outer-space> accessed 6 June 2019.

⁷ In 2009, the Chinese Air Force chief Xu Qiliang stated that ‘competition between military forces’ in space was ‘a historical inevitability', see Sydney Freedberg, ‘Pentagon Reports on China’s Satellite Killers’ (Break ing Defense, 11 May 2015) <https://breakingdefense.com/2015/05/pentagon-reports-on- chinas-satellite-killers/> accessed 6 June 2019; Likewise, other nations like the US, are preparing for such scenarios, see David Martin, ‘The Battle Above’ (CBS, 2 August 2015) <https://www.cbsnews.com/news/rare-look-at-space-command-satellite-defense-60-minutes-2/> accessed 9 July 2019.

⁸ Bryan Bender and Jacqueline Klimas, ‘Space war is coming – and the U.S. is not ready’ (Politico, 6 April 2018) <https://www.politico.com/story/2018/04/06/outer-space-war-defense-russia-china- 463067> accessed 9 July 2019.

⁹ Jürgen Scheffran, ‘Dual-Use in a New Security Environment The Case of Missiles and Space’ [2006] 26 INESAP Information Bulletin 48, 49.

¹⁰ Also referred to as International Humanitarian Law (IHL).

¹¹ Charter of the United Nations (signed 26 June 1945, entered into force 24 October 1945) 1 UNTS XVI [hereinafter UN Charter].

¹² Martyn Thomas (ed), Global Navigation Space Systems: reliances and vulnerabilities (The Royal Academy of Engineering 2011); Andrea Shalal, ‘U.S. eyes new ways to prepare and win future war in space’ (Reuters, 17 April 2015) <https://www.reuters.com/article/us-usa-military-space-future- idUSKBN0N82E820150417> accessed 6 June 2019.

¹³ Thomas (n 12).

¹⁴ Steven Freeland, ‘The Laws of War in Outer Space’ in Schrogl and others (n 3) 81-109; Brian Weeden and Victoria Samson (eds), Globa l Counterspace Capabilities: An Open Source Assessment (Secure World Foundation 2019).

¹⁵ The international regime governing inter-State armed force.

¹⁶ The LOAC, which is the international regime regulating the conduct of hostilities during armed conflict.

¹⁷ Unusable artificial satellites are all other man-made objects in orbit.

¹⁸ Legally, the UN space treaties do mention satellites in particular and rather refer to ‘space objects’, which are all man-made objects (including their component parts as well as their launch vehicles and parts thereof) launched into outer space, see for example Art. I (b) of the Convention on Registration of Objects Launched into Outer Space (signed 12 November 1974, entered into force 15 September 1976) 1023 UNTS 15 [hereinafter REG].

¹⁹ Elizabeth Howell, ‘What is a Satellite?’ (space.com, 27 October 2017) <https://www.space.com/24839-satellites.html> accessed 23 July 2019.

²⁰ Scheffran (n 9) 48.

²¹ Jackson Maogoto and Steven Freeland, ‘Space Weaponization and the United Nations Charter Regime on Force: A Thick Legal Fog or a Receding Mist?’, [2007] 41 (4) The International Lawyer 1091, 1100.

²² Scheffran (n 9) 48.

²³ ibid 49.

²⁴ Gérardine Goh, ‘Keeping the peace in outer peace: a legal framework for the prohibition of the use of force’ [2004] 20 Space Policy 259, 269.

²⁵ Dale Stephens and Cassandra Steer, ‘Conflicts in Space: International Humanitarian Law and its Application to Space Warfare’ [2015] XL Annals of Air and Space Law 1, 20; Colin Clark, ‘US Presses Russia, China on ASAT Tests; Space Control Spending Triples’ (Breaking Defense, 16 April 2015) <https://breakingdefense.com/2015/04/space-control-spending-triples/> accessed 6 June 2019; Michel Bourbonnière, ‘Law of Armed Conflict (LOAC) and the Neutralisation of Satellites or Ius In Bello Satellitis ’ [2004] 9 (1) Journal of Conflict & Security Law 43, 45.

²⁶ Michel Bourbonnière and Ricky Lee, ‘Legality of the Deployment of Conventional Weapons in Earth Orbit: Balancing Space Law and the Law of Armed Conflict’ [2008] 18 (5) The European Journal of International Law 874, 893.

²⁷ For example their function is simply described as “Earth Remote Sensing” or “Communication Satellite”, see Bernhard Schmidt-Tedd, Nataliya Malysheva, and Olga Stelmakh, ‘Article IV (Information by Each State of Registry)’ in Stephan Hobe, Bernhard Schmidt-Tedd, and Kai-Uwe Schrogl (eds), Cologne Commentary on Space Law, Rescue Agreement, Liability Convention, Registration Convention, Moon Agreement (Carl Heymanns Verlag 2013) 302.

²⁸ Goh (n 24) 268.

²⁹ Goh (n 24) 270; Scheffran (n 9) 48; Shalal (n 12).

³⁰ Joseph Pelton, ‘Future of Military Satellite Systems’ in Joseph Pelton, Scott Madry, and Sergio Camacho-Lara (eds) Handbook of Satellite Applications (Springer 2015) 7-10; Sandra Erwin, ‘Space Force discussions increasingly blur the line between military and civilian space’ (SpaceNews, 31 October 2018) <https://spacenews.com/space-force-discussions-increasingly-blur-the-line-between- military-and-civilian-space/> accessed 9 July 2019.

³¹ Peter Cunningham, ‘Military Payloads Hosted on Commercial Satellites’ [2015] 53 Air Command and Staff College Wright Flyer Paper 3; US Department of Defense and Office of the Director of National Intelligence, Na tional Security Space Strategy Unclassified Summary (2011) 5; Shalal (n 12); Dale Stephens, ‘Why Outer Space Matters: Dr. Dale Stephens Gives a Brief Introduction to International Humanitarian Law’ (IKRK, 7 November 2016) <http://intercrossblog.icrc.org/blog/twmzia1cp84kv2c29bi4iz6q4u03in> accessed 6 June 2019.

³² Ricky Lee and Sarah Steele, ‘Military Use of Satellite Communications, Remote Sensing, and Global Positioning Systems in the War on Terror’ [2014] 79 (1) Journal of Air Law and Commerce 69, 80.

³³ Thomas (n 12) 13-14.

³⁴ Position finding and navigation satellites are able to provide precise34, real-time data on the positions of mobile objects on the ground. Such data is provided by GNSS (such as the American GPS, the European Galileo, the Chinese Beidou, or the Russian GLONASS) for both civilian and military users. Especially the GPS, originally developed by and for the US military, today also enables many vital civilian functions (for example in the areas of disaster management, banking and transport), see Lee and Steele (n 32) 71.

³⁵ ‘Communication satellites are able to transmit a vast range of data with high speed and assure almost instant global communication, regardless or the distances or positions involved.’ Technical devices and communication technologies have been and increasingly become more interconnected into a global network of which satellites are a vital part, see Scheffran (n 9) 50.

³⁶ Remote sensing satellites are used for Earth observation and monitor the Earth with multispectral scanners to collect data.

³⁷ Scheffran (n 9) 50.

³⁸ Thomas (n 12); Krystal Wilson, ‘Why Outer Space Matters: Krystal Wilson on Humanitarian Uses of Space’ (IKRK, 18 October 2016) <http://intercrossblog.icrc.org/blog/why-outer-space-matters-krystal- wilson-on-humanitarian-uses-of-space> accessed 16 July 2019.

³⁹ Michael Schmitt, ‘International Law and Military Operations in Space’ [2006] 10 Max Planck Yearbook of United Nations Law 89, 91; Scheffran (n 9) 50; Weeden and Samson (n 14) vv.

⁴⁰ Thomas (n 12) 7.

⁴¹ Shalal (n 12).

⁴² Thomas (n 12).

⁴³ Chris Baraniuk, ‘GPS error caused ’12 hours of problems’ for companies’ (BBC, 4 February 2016) <https://www.bbc.co.uk/news/technology-35491962> accessed 24 July 2019.

⁴⁴ Alan O’Connor and others, Econom ic Benefits of the Global Positioning System (GPS) (RTI International 2019) ES-4.

⁴⁵ ibid 5-13.

⁴⁶ Shalal (n 12).

⁴⁷ Also referred to as orbital debris.

⁴⁸ UN COPUOS Inter-Agency Space Debris Coordination Committee space debris mitigation guidelines (29 November 2002) UN Doc A/AC.105/C.1/L.260, declared as State practice and endorsed by UNGA Resolution 62/217 (22 December 2007) UN Doc A/RES/62/217.

⁴⁹ For example United Nations, ‘Outer Space Increasingly ‘Congested, Contested and Competitive’, First Committee Told, as Speakers Urge Legally Binding Document to Prevent Its Militarization’ (UN, 25 October 2013) <https://www.un.org/press/en/2013/gadis3487.doc.htm> accessed 28 June 2019.

⁵⁰ Already back in 1978, NASA scientist Donald Kessler first described the so-called “Kessler Syndrome” or “Kessler effect”. The increasing number of space objects – consisting space debris, satellites, and other man-made objects – in Earth’s LEO would grow so large that collisions would become inevitable. The resulting new debris would eventually lead to an exponential growth (cascade effect) of space debris as there was an accompanying exponential growth of collisions. The LEO might become useless to mankind, see Donald Kessler and Burton Cour-Palais, ‘Collision Frequency of Artificial Satellites: The Creation of a Debris Belt’ [1978] 83 (A6) Journal of Geophysical Research 2637; Duncan Blake, ‘Military Strategic Use of Outer Space’ in Hitoshi Nasu and Robert McLaughlin (eds), New Technologies and the Law of Armed Conflict (Springer 2014) 115.

⁵¹ The number of space operators and countries owing space assets is constantly growing. The space debris population is likewise constantly increasing.

⁵² The dependence on space-based systems has increased enormously over the last six decades, but also their vulnerability due to the development of new offensive capabilities (see subsections 2.1. and 2.3.).

⁵³ Commercial space operators are increasingly driving competition for higher performance and lower cost space systems. At the same time, space as the “ultimate military highground” and its economic benefits is a (potential) cause for geopolitical tensions.

⁵⁴ European Space Agency, ‘Space Debris by the Numbers’ (ESA, January 2019) <http://m.esa.int/Our_Activities/Space_Safety/Space_Debris/Space_debris_by_the_numbers> accessed 28 June 2019.

⁵⁵ Tanja Masson-Zwaan, ‘The International Framework for Space Activities’ in Christopher Johnson (ed), Handbook for New Actors in Space (Secure World Foundation 2017) 33.

⁵⁶ European Space Agency, ‘Space Debris by the Numbers’ (n 54).

⁵⁷ William Ailor and Holger Krag, ‘Space Debris and Space Safety: Looking Forward’ [2009] 62 JBIS 261.

⁵⁸ William Ailor and others, ‘Space Debris and the Cost of Space Operations’ (Proceedings of the Fourth IAASS Conference ‘Making Safety Matter’, Huntsville, 2010) 1.

⁵⁹ Hillary Lamb, ‘Space agencies join forces to tackle problem of small debris in low Earth orbit’ (E&T, 19 January 2018) <https://eandt.theiet.org/content/articles/2018/01/space-agencies-tackle-problem-of- small-space-debris-in-low-earth-orbit/> accessed 24 July 2019.

⁶⁰ Masson-Zwaan (n 55) 40.

⁶¹ William Ailor, ‘Space traffic control: issues and options’ in Wolfgang Rathgeber, Kai-Uwe Schrogl, and Ray Williamson (eds), The Fair and Responsible Use of Space: An International Perspective, Studies in Space Policy vol 4 (Springer 2010) 123.

⁶² William Ailor, ‘Space Traffic Management’ in Schrogl and others (n 3) 233-235.

⁶³ Karl Tate, ‘Space Junk Explained: How Orbital Debris Threatens Future of Spaceflight (Infographic)’ (space .com, 2 October 2013) <https://www.space.com/23039-space-junk-explained- orbital-debris-infographic.html> accessed 16 July 2019.

⁶⁴ Brian Weeden, ‘Anti-Satellite Tests in Space – The Case of China’ (Secure World Foundation, 16 August 2013) <https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=2a hUKEwi5icDvjavjAhVHZcAKHflfDpcQFjAAegQIABAC&url=https%3A%2F%2Fswfound.org%2F media%2F115643%2Fchina_asat_testing_fact_sheet_aug_2013.pdf&usg=AOvVaw0e3o7Vcoz98qLN 5512CivV> accessed 10 July 2019.

⁶⁵ Besides many more smaller, untrackable pieces of debris.

⁶⁶ Weeden, ‘Anti-Satellite Tests in Space – The Case of China’ (n 64).

⁶⁷ Joel Spark, ‘ISS Dodges Chinese ASAT Debris’ (Spac e Safety Magazine, 30 January 2012) <http://www.spacesafetymagazine.com/news/iss-forced-dodge-chinese-asat-debris/> accessed 25 July 2019.

⁶⁸ Brian Weeden, ‘Why Outer Space Matters: Brian Weeden on Natural and Human-generated Threats on Satellites’ (IKRK, 24 October 2016) <http://intercrossblog.icrc.org/blog/why-outer-space-matters- brian-weeden-on-natural-and-human-generated-threats-on-satellites> accessed 6 June 2019.

⁶⁹ Melissa De Zwart, ‘New Technologies Symposium: Contested and Fragile – The Dual-Use Space Environment’ (Op inioJuris, 7 May 2019) <http://opiniojuris.org/2019/05/07/new-technologies- symposium-contested-and-fragile-the-dual-use-space-environment/> accessed 29 June 2019.

⁷⁰ Weeden, ‘Why Outer Space Matters’ (n 68).

⁷¹ Maogoto and Freeland (n 21); De Zwart (n 69).

⁷² Percy Blount, ‘Targeting in Outer Space: Legal Aspects of Operational Military Actions in Space’ [2012] Harvard National Security Journal 1, 2.

⁷³ For example European Space Agency, ‘Active Debris Removal’ (ESA, 2019) <https://m.esa.int/Our_Activities/Space_Safety/Space_Debris/Active_debris_removal> accessed 24 July 2019.

⁷⁴ Aiming at improving international cooperation and work out transparency and confidence-building measures, see Christopher Johnson, ‘The UN Group of Governmental Experts on Space TCBMs’ (Secur e World Foundation, April 2014) <https://swfound.org/media/109311/swf_gge_on_space_tcbms_fact_sheet_april_2014.pdf> accessed 6 June 2019.

⁷⁵ Council of the European Union (9 December 2008) EU Doc 17175/08; A non-binding, voluntary international instrument originally proposed by the European Union in 2008 and aimed at building norms of responsible behaviour in space activities, policies and procedures to prevent and minimise space debris. It was negotiated until 2014, but never made it past the draft status, see Christopher Johnson, ‘Draft International Code of Conduct for Outer Space Activities Fact Sheet’ (Secure World Foundation, February 2014) <https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=2&cad=rja&uact=8&ved=2a hUKEwj54P2bhqjjAhUUEcAKHaZJDUYQFjABegQIChAE&url=https%3A%2F%2Fswfound.org%2 Fmedia%2F166384%2Fswf_draft_international_code_of_conduct_for_outer_space_activities_fact_she et_february_2014.pdf&usg=AOvVaw1DVSEdejjxChdB8cT5ksdZ> accessed 9 July 2019; Max

⁷⁶ (n 48).

⁷⁷ UN COPUOS Guidelines for the Long-term Sustainability of Outer Space Activities (27 June 2018) UN Doc A/AC.105/2018/CRP.20, a compilation of best practices and soft law to be implemented voluntarily on the national level, aimed at preserving the space environment, ensuring the exploration and use of outer space for peaceful purposes and limiting the growth of space debris.

⁷⁸ Bin Cheng, Studies in International Space Law (OUP 1997) 127-150.

⁷⁹ The last of the five UN treaties on outer space, the Moon Agreement, has been concluded back in 1984 and has only eleven signatories, Agreement Governing the Activities of States on the Moon and Other Celestial Bodies (signed 18 December 1979, entered into force 11 July 1984) 1363 UNTS 3 [hereinafter Moon Agreement].

⁸⁰ Fabio Tronchetti, ‘Soft Law’ in Brünner and Soucek (n 2) 619-633.

⁸¹ Theresa Hitchens, ‘U.S. India ASAT Test React May Backfire, Experts Say’ (Breaking Defense, 3 April 2019) <https://breakingdefense.com/2019/04/u-s-india-asat-test-react-may-backfire-experts-say/> accessed 6 June 2019.

⁸² Mainly the US, China, and Russia, but also other countries like Brazil, India, Iran, or North Korea, see for example Weeden and Samson (n 14); Jessica West, ‘Why the chances of conflict in outer space are going up’ [2018] 39 (4) The Ploughshares Monitor 8.

⁸³ Weeden and Samson (n 14) xv.

⁸⁴ ibid.

⁸⁵ For a basic overview over dedicated and non-dedicated ASAT weapons, see Scheffran (n 9) 50-51.

⁸⁶ ‘[W]eapons that use ground, air-, or sea-launched missiles with interceptors that are used to kinetically destroy satellites through force of impact, but are not placed in orbit themselves’, Weeden and Samson (n 14) xv.

⁸⁷ ‘[W]eapons that are placed into orbit and then maneuver to approach the target’ to destroy it, ibid.

⁸⁸ ‘[W]eapons that use radiofrequency energy to interfere with or jam the communication to or from satellites’, ibid.

⁸⁹ ‘[W]eapons that use focused energy, such as laser, particle, or microwave beams to interfere or destroy space systems’, ibid.

⁹⁰ ‘[W]eapons that use software and network techniques to compromise, control, interfere, or destroy computer systems’, ibid.

⁹¹ Schmitt, ‘International Law and Military Operations in Space’ (n 39) 96.

⁹² Colin Clark, ‘Chinese ASAT Test Was ‘Successful:’ Lt. Gen. Raymond’ (Breaking Defense, 14 April 2015) <https://breakingdefense.com/2015/04/chinese-asat-test-was-successful-lt-gen-raymond/> accessed 6 June 2019; Colin Clark, ‘India Anti-Satellite Strike: Less Debris Likely, Not Like China’s’ (Break ing Defense, 28 March 2019) <https://breakingdefense.com/2019/03/india-anti-satellite-strike- less-debris-likely-not-like-chinas/> accessed 6 June 2019.

⁹³ Weeden and Samson (n 14) viii.

⁹⁴ Theresa Hitchens, Peaceful uses of outer space vs. militarization: a cost-benefit analysis, in Rathgeber, Schrogl, and Williamson (n 61) 46-47.

⁹⁵ Consider the GGE process on Further Practical Measures for the Prevention of an Arms Race in Outer Space, UNGA Resolution 72/250 (24 December 2017) UN Doc A/RES/72/250; also consider the drafting and negotiation process of the Draft Treaty on the Prevention of the Placement of Weapons in Outer Space, the Threat or Use of Force against Space Objects, Mutschler (n 75) 43-48.

⁹⁶ Blake (n 50) 122-126.

⁹⁷ UN Charter (n 11).

⁹⁸ Vienna Convention on the Law of Treaties (signed 23 May 1969, entered into force 27 January 1980) 1155 UNTS 331.

⁹⁹ Most of which today enjoy wide ratification.

¹⁰⁰ Freeland (n 14) 91.

¹⁰¹ This concerns all of the provisions discussed below if not indicated otherwise; Ricky Lee, ‘The Jus Ad Bellum in Spatialis: The Exact Content and Practical Implications of the Law on the Use of Force in Outer Space’ [2003] 29 Journal of Space Law 93; Goh (n 24) 260; Michael Schmitt (ed), Tallinn Manual 2.0 on the International Law Applicable to Cyber Operations (1st edn, CUP 2017) 270.

¹⁰² Cheng (n 78) 127-150; Tronchetti (n 80) 619-633.

¹⁰³ Micheal Sheehan, ‘Defining Space Security’ in Schrogl and others (n 3) 12-13; Mutschler (n 75) 43- 48; Bourbonnière and Lee (n 26) 890.

¹⁰⁴ And for the application of IHL (see subsection 4.2.).

¹⁰⁵ Art. 1 of the Chicago Convention establishes the pre-eminence of national law and thus the sovereignty of the subjacent State over its respective airspace, Convention on International Civil Aviation (signed 7 December 1944, entered into force 4 April 1947) 15 UNTS 295.

¹⁰⁶ Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies (signed 27 January 1967, entered into force 10 October 1967) 610 UNTS 205 [hereinafter OST].

¹⁰⁷ Masson-Zwaan (n 55) 12

¹⁰⁸ Paul Voosen, ‘Outer space may have just gotten a bit closer’ (ScienceMag, 24 July 2018) <https://www.sciencemag.org/news/2018/07/outer-space-may-have-just-gotten-bit-closer> accessed 28 July 2019.

¹⁰⁹ Blake (n 50) 137.

¹¹⁰ Edward Finch, ‘Outer Space for “Peaceful Purposes”’ [1968] 54 (4) American Bar Association Journal 365.

¹¹¹ Goh (n 24).

¹¹² Also for example in The Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space, UNGA Resolution 1962 (XVIII) (13 December 1963) UN Doc A/RES/1962(XVIII); and repeated in various other legal outer space instruments.

¹¹³ Blount (n 72) 2.

¹¹⁴ Art. I of The Antarctic Treaty (signed 1 December 1959, entered into force 23 June 1961) 402 UNTS 71.

¹¹⁵ Art. 88 of the United Nations Convention on the Law of the Sea (signed 10 December 1982, entered into force 16 November 1994) 1833 UNTS 3 [hereinafter UNCLOS].

¹¹⁶ Finch (n 110); Ricky Lee, ‘Jus Ad Bellum in Outer Space: The Interrelation between Article 103 of the Charter of the United Nations and Article IV of the Outer Space Treaty’ [2002] 45 Proceedings on the Law of Outer Space 139, 140; Masson-Zwaan (n 55) 8-9.

¹¹⁷ Bourbonnière and Lee (n 26) 877.

¹¹⁸ UN Charter (n 11).

¹¹⁹ Bourbonnière and Lee (n 26).

¹²⁰ ibid; Blake (n 50) 118.

¹²¹ Schmitt, Tallinn Manual 2.0 (n 101) 273.

¹²² Goh (n 24) 261.

¹²³ Dale Stephens, ‘The International Legal Implications of Military Space Operations: Examining the Interplay between International Humanitarian Law and the Outer Space Legal Regime’ [2018] 94 International Law Studies 75, 87-88.

¹²⁴ Schmitt, Tallinn Manual 2.0 (n 101) 377.

¹²⁵ Moon Agreement (n 79).

¹²⁶ Shah (n 6); United Nations, ‘Stronger Rules Must Guarantee Outer Space Remains Conflict-Free, First Committee Delegates Stress, Calling for New Laws to Hold Perpetrators Accountable’ (UN, 17 October 2017) <https://www.un.org/press/en/2017/gadis3583.doc.htm> accessed 10 July 2019; United Nations, ‘Raising Alarm over Possible Space Wars, First Committee Delegates Explore Ways to Build New Order for Preventing Celestial Conflict, Confrontation’ (UN, 24 October 2018) <https://www.un.org/press/en/2018/gadis3609.doc.htm> accessed 10 July 2019.

¹²⁷ The US, Russia, China, and also the European Countries.

¹²⁸ Legality of the Threat or Use of Nuclear Weapons, Advisory Opinion [1996] ICJ Rep 226 [hereinafter Nuclear Weapons Advisory Opinion] para 70.

¹²⁹ Goh (n 24) 260.

¹³⁰ UNGA Resolution 72/250 (24 December 2017) UN Doc A/RES/72/250.

¹³¹ Cheng (n 78) 127-150.

¹³² Tronchetti (n 80) 619-633.

¹³³ UN Charter (n 11).

¹³⁴ Carlos Bernheim, ‘United States Armed Intervention in Nicaragua and Article 2(4) of the United Nations Charter’ [1985] 11 Yale Journal of International Law 104, 104; see also for example Military and Paramilitary Activities in and against Nicaragua (Nicaragua v. United States of America) (Merits, separate opinion of President Nagendra Singh) [1986] ICJ Rep 14 [hereinafter Nicaragua case], 153 (‘the very cornerstone of the human effort to promote peace in a world torn by strife’).

¹³⁵ Nicaragua case (n 134) para 190.

¹³⁶ Tom Ruys, ‘The Meaning of “Force” and the Boundaries of the Jus Ad Bellum: Are “Minimal” Uses of Force excluded from UN Charter Article 2(4)?’ [2014] 108 (2) AJIL 159.

¹³⁷ ibid 187.

¹³⁸ Nicaragua case (n 134) para 176.

¹³⁹ ibid para 194.

¹⁴⁰ Susan Lamb, ‘Legal Limits to United Nations Security Council Powers’ in Guy Goodwin-Gill and Stefan Talmon (eds), The Reality of International Law: Essays in Honour of Ian Brownlie (OUP 1999) 361-388.

¹⁴¹ Lee, ‘Jus Ad Bellum in Outer Space’ (n 116).

¹⁴² Monica Hakimi and Jacob Cogan, ‘The Two Codes on the Use of Force’ [2016] 27 (2) The European Journal of International Law 257, 257.

¹⁴³ Such territory is principally incapable of being placed under sovereign control and belongs to all mankind. According to Art. I OST (n 106 ), outer space is ‘the province of all mankind’ and Art. II OST states that outer space is not subject to any means of national appropriation. Another prominent example of re s communis are the high seas (the ‘Common heritage of mankind’, Art. 136 UNCLOS (n 115)), see Stephan Hobe, ‘Article I’ in Stephan Hobe, Bernhard Schmidt-Tedd, and Kai-Uwe Schrogl (eds), Co logne Commentary on Space Law, Outer Space Treaty (Berliner Wissenschafts-Verlag 2017) 167-220; Ram Jakhu and Steven Freeland, ‘Article II’ in Hobe, Schmidt-Tedd, and Schrogl (n 143) 221-270.

¹⁴⁴ Schmitt, Tallinn Manual 2.0 (n 101) 329.

¹⁴⁵ Goh (n 24) 263.

¹⁴⁶ OST (n 106).

¹⁴⁷ Olivier Ribbelink, ‘Article III’ in Hobe, Schmidt-Tedd, and Schrogl (n 143) 274.

¹⁴⁸ That is each State Party to the OST (and because it is a customary rule, each State) that launches or procures the launching of an object into outer space, including the Moon and other celestial bodies, and each State Party from whose territory or facility an object is launched, Arts. VII OST, I (a) REG (n 18).

¹⁴⁹ OST (n 106).

¹⁵⁰ REG (n 18).

¹⁵¹ Bernhard Schmidt-Tedd and Stephan Mick, ‘Article VIII’ in Hobe, Schmidt-Tedd, and Schrogl (n 143) 520-524.

¹⁵² UNCLOS (n 115).

¹⁵³ (n 134) para 212.

¹⁵⁴ (n 128) para 39.

¹⁵⁵ Schmitt, Tallinn Manual 2.0 (n 101) 330.

¹⁵⁶ Lee, ‘Jus Ad Bellum in Outer Space’ (n 116); Masson-Zwaan (n 55) 8-9.

¹⁵⁷ Cheng (n 78) 70-72.

¹⁵⁸ Nuclear Weapons Advisory Opinion (n 128) para 79.

¹⁵⁹ Stephens and Steer (n 25) 12.

¹⁶⁰ Note that the ICRC Study on Customary IHL does not once cite evidence of State practice regarding outer space, see Jean-Marie Henckaerts and Louise Doswald-Beck, Cus tomary International Humanitarian Law (CUP 2005).

¹⁶¹ Convention on the Prohibition of Military or Any Other Hostile Use of Environmental Modification Techniques (signed 10 December 1976, entered into force 5 October 1978) 1108 UNTS 151 [hereinafter ENMOD].

¹⁶² Kubo Mačák, ‘Silent War: Applicability of the Jus in Bello to Military Space Operations’ [2018] 94 International Law Studies 1.

¹⁶³ Schmitt, Tallinn Manual 2.0 (n 101) 3.

¹⁶⁴ Mačák (n 162) 23.

¹⁶⁵ OST (n 106).

¹⁶⁶ Schmitt, Tallinn Manual 2.0 (n 101) 276; Stephens and Steer (n 25).

¹⁶⁷ (n 126) para 86.

¹⁶⁸ Stephens and Steer (n 25).

¹⁶⁹ Protocol Additional to the Geneva Conventions of 12 August 1949, and Relating to the Protection of Victims of International Armed Conflicts (Protocol I) (signed 12 August 1977, entered into force 7 December 1978) 1125 UNTS 3 [hereinafter AP I].

¹⁷⁰ See for example, Geneva Convention Relative to the Protection of Civilian Persons in Time of War, (signed 12 August 1949, entered into force 21 October 1950) 75 UNTS 287.

¹⁷¹ (n 169).

¹⁷² Schmitt, ‘International Law and Military Operations in Space’ (n 39) 115.

¹⁷³ Schmitt, Tallinn Manual 2.0 (n 101) 414.

¹⁷⁴ ibid 415.

¹⁷⁵ (n 169).

¹⁷⁶ Richard Desgagne, ‘International Humanitarian Law in Outer Space’ (ASEAN Regional Forum Workshop on Space Security, Beijing, 2015) 3.

¹⁷⁷ Schmitt, Tallinn Manual 2.0 (n 101) 415.

¹⁷⁸ Schmitt, ‘International Law and Military Operations in Space’ (n 39) 117.

¹⁷⁹ ICRC, ‘International humanitarian law and the challenges of contemporary armed conflicts Report’ (32nd International Conference of the Red Cross and Red Crescent, Geneva, 2015) 41.

¹⁸⁰ Stephens, ‘Why Outer Space Matters’ (n 31).

¹⁸¹ Codified in Art. 48 AP I (n 169); Rule 1 of the ICRC Study on Customary IHL, Henckaerts and Doswald-Beck (n 160) 3.

¹⁸² Nils Melzer, ‘The Principle of Distinction Between Civilians and Combatants’ in Andrew Clapham and Paolo Gaeta (eds), Th e Oxford Handbook of International Law in Armed Conflict (OUP 2014) 296.

¹⁸³ Nuclear Weapons Advisory Opinion (n 128) para 78.

¹⁸⁴ ibid para 79.

¹⁸⁵ ibid paras 82-83.

¹⁸⁶ Art. 52 (2) AP I (n 169).

¹⁸⁷ Mačák (n 162) 6.

¹⁸⁸ Goh (n 24) 268; Blount (n 72) 10.

¹⁸⁹ Blake (n 50) 134.

¹⁹⁰ Blount (n 72) 6-8; Blake (n 50) 135.

¹⁹¹ Art. 57 (2) (a) (i) AP I (n 169).

¹⁹² Art. 52 (3) AP I (n 169).

¹⁹³ This does not require absolute certainty, since doubt is frequently present during armed conflict. What is required is sufficiently reliable information and efforts to obtain such information before the attack so that a reasonable commander can conclude that he is about to target a legitimate military objective, see Schmitt, Ta llinn Manual 2.0 (n 101) 448.

¹⁹⁴ Yoram Dinstein, Th e Conduct of Hostilities Under the Law of International Armed Conflict, (CUP 2004) 120.

¹⁹⁵ Melzer (n 182) 296.

¹⁹⁶ Bourbonnière (n 25) 49.

¹⁹⁷ Arts. 51 (5) (b), 57 (2) (a) (iii) AP I (n 169); Rule 14 of the ICRC Study on Customary IHL, Henckaerts and Doswald-Beck (n 160) 46.

¹⁹⁸ Not mere speculative, see Schmitt, Ta llinn Manual 2.0 (n 101) 476.

¹⁹⁹ Jean-François Quéguiner, ‘Precautions under the law governing the conduct of hostilities’ [2006] 88 (864) International Review of the Red Cross 793, 794.

²⁰⁰ Art. 57 AP I (n 169); Rules 15 and 22 of the ICRC Study on Customary IHL , Henckaerts and Doswald-Beck (n 160) 51-68.

²⁰¹ Meaning ‘the immediate, first order consequences [of the attack], unaltered by intervening events or mechanisms’, see Schmitt, Tallinn Manual 2.0 (n 101) 476.

²⁰² Meaning ‘the delayed and/or displaced second-, third-, or higher-order consequences of actions, created through intermediate events or mechanisms’, see ibid.

²⁰³ Henckaerts and Doswald-Beck (n 160) 54.

²⁰⁴ Bourbonnière (n 25) 61; Henckaerts and Doswald-Beck (n 160) 46.

²⁰⁵ Absolute certainty is not required; reliable information so that a reasonable commander can factor an educated assessment is sufficient, see Schmitt, Ta llinn Manual 2.0 (n 101) 435.

²⁰⁶ Goh (n 24) 268.

²⁰⁷ Dinstein (n 194) 120.

²⁰⁸ Bourbonnière (n 25) 60-61.

²⁰⁹ Art. 57 (3) AP I (n 169).

²¹⁰ Stephens, ‘Why Outer Space Matters’ (n 31).

²¹¹ Weapons and associated systems, ‘means of warfare that are used, designed, or intended to be used to cause injury to, or death of, persons or damage to, or destruction of, objects, […] that result in the consequences required for qualification of […] as an attack, see Schmitt, Ta llinn Manual 2.0 (n 101) 452.

²¹² Tactics, techniques, and procedures by which hostilities are conducted, see ibid 453.

²¹³ Art. 35 (1) AP I (n 169); Rule 45 of the ICRC Study on Customary IHL , Henckaerts and Doswald- Beck (n 160) 151.

²¹⁴ (n 128) para 86.

²¹⁵ ibid para 78; also established by Art. 51 (4) AP I (n 169); Rule 71 of the ICRC Study on Customary IHL , Henckaerts and Doswald-Beck (n 160) 244.

²¹⁶ Art. 35 (2) AP I (n 169); Rule 70 of the ICRC Study on Customary IHL , Henckaerts and Doswald- Beck (n 160) 237.

²¹⁷ ‘Superfluous injury and unnecessary suffering’ refers to a situation where a weapons causes ‘a greater harm than that unavoidable to achieve legitimate military objectives’, Nuclear Weapons Advisory Opinion (n 128) para 78.

²¹⁸ Blake (n 50) 133.

²¹⁹ This does not prohibit collateral harm, see Dinstein (n 194) 72-102.

²²⁰ It has been noted that imprecise means and methods are not covered by this provision, but rather those which are impossible to predict with any reasonable certainty whether it will strike a military objective rather than civilian object, see Schmitt, Tallinn Manual 2.0 (n 101) 455; Blount (n 72) 21.

²²¹ In the second Tallinn Manual, reference was made to certain malware spreading uncontrollable into civilian computer networks after being introduced against military networks, see Schmitt, Tallinn Manual 2.0 (n 101) 455; other examples include WMD or environmental modification techniques, see Henckaerts and Doswald-Beck (n 160) 249-250.

²²² OST (n 106).

²²³ Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Underwater (signed 5 August 1963, entered into force 10 October 1963) 480 UNTS 43 [hereinafter LTBT].

²²⁴ OST (n 106).

²²⁵ (n 223).

²²⁶ Kai-Uwe Schrogl and Julia Neumann, ‘Article IV’ in Hobe, Schmidt-Tedd, and Schrogl (n 143) 308.

²²⁷ Goh (n 24) 261.

²²⁸ Lee, ‘Jus Ad Bellum in Outer Space’ (n 116) 140.

²²⁹ Bourbonnière and Lee (n 26) 881.

²³⁰ Schrogl and Neumann (n 226) 310.

²³¹ Schmitt, ‘International Law and Military Operations in Space’ (n 39) 111; Pavle Kilibarda, ‘Space law revisited (2/3): Are weapons of mass destruction prohibited in space?’ (ICRC, 21 December 2016) <https://blogs.icrc.org/law-and-policy/2016/12/21/space-law-weapons-mass-destruction/> accessed 17 July 2019.

²³² There is no definition of WMD under international law, but generally they are considered to comprehend nuclear, chemical, radiological, and biological weapons. Although certain ASAT weapons cause large-scale destruction due to space debris, ASAT weapons do not reach the level of WMD. Furthermore, there are no chemical and biological ASAT weapons, see for example Pavle Kilibarda, ‘Space law revisited: The militarization of outer space’ (ICRC, 9 March 2017) <https://medium.com/law-and-policy/space-law-revisited-the-militarization-of-outer-space- d65df7359515> accessed 6 June 2019; Lee and Steele (n 32) 107-108.

²³³ Kilibarda, ‘Space law revisited (2/3)’ (n 231).

²³⁴ Karl Hebert, ‘Regulation of Space Weapons: Ensuring Stability and Continued Use of Outer Space’ [2014] 12 (1) Astropolitics 1.

²³⁵ Ray Williamson, ‘Fairness and responsibility in space activities’ in Rathgeber, Schrogl, and Williamson (n 61) 16.

²³⁶ United Nations (n 126).

²³⁷ Nuclear Weapons Advisory Opinion (n 128) para 30.

²³⁸ ibid para 29.

²³⁹ Blake (n 50) 133.

²⁴⁰ Arts. 35 (3), 55 (1) AP I (n 169); Rule 45 of the ICRC Study on Customary IHL , Henckaerts and Doswald-Beck (n 160) 151.

²⁴¹ Bourbonnière (n 25) 64.

²⁴² (n 161); it is the only IHL environmental convention that explicitly refers to outer space (see subsection 4.2.), but has narrower prohibitions than AP I (n 169), see Blount (n 72) 21.

²⁴³ Schmitt, Tallinn Manual 2.0 (n 101) 537.

²⁴⁴ See for example (n 48); (n 77).

²⁴⁵ Bourbonnière (n 25) 64; Schmitt, Tallinn Manual 2.0 (n 101) 537.

²⁴⁶ Blount (n 72) 20-21.