The Space Law Review: International Treaties

I Introduction

The world's first satellite, Sputnik 1, was launched by the former Soviet Union (now Russia) on 4 October 1957. On 6 April 1965, the United States placed the first geostationary satellite, Intelsat 1, in orbit. From these early steps we now have a significant number of (peaceful civilian) commercial uses of outer space, including: broadcasting; telecommunications (fixed, land and maritime mobile satellite services); navigation, including the global positioning system and the global navigation satellite system; Earth observation; and meteorology. The military also make extensive use of outer space. Today, initiatives such as government satellite communications illustrate that space is increasingly used for the provision of both governmental and commercial satellite services for security and military purposes and governmental applications.

Satellites are by their nature extraterrestrial and extraterritorial. Accordingly, their usage is governed by an extensive international legal framework, under the aegis of the United Nations, made up of treaties, agreements and conventions governed by international law, which may be implemented into national law.

The legal framework governing the use of satellites is also grounded in the allocation of orbital positions for satellites, particularly for geostationary satellites, and the allocation and assignment of radio-frequency spectrum to enable communication to and from the satellites, and the related frequencies for terrestrial use of those communications. In relation to orbital positions, satellites in geostationary orbits are in 'fixed' positions approximately 36,000 kilometres above Earth, and satellites in medium and low orbits operate at lower altitudes.

To enable 'fair and equitable' use of the finite space closely surrounding Earth, coordination of these positions is based on the need for satellites not to interfere with each other physically, which is important with regard to the radio frequency spectrum (also finite, although some prefer to say 'scarce') used by satellites so as to prevent 'harmful interference' between the services using different spectrum.

The allocation and coordination of spectrum and orbital slots is dealt with separately in Chapter 2 on the International Telecommunication Union and access to spectrum.

II UN space treaties

During the Cold War period, there was an increasing emphasis on the development of national military capabilities, especially in the Soviet Union and the United States, and the building of intercontinental ballistic missiles using rocket technology. The launch of Sputnik 1 was the catalyst for the space race between these countries, and the concern that outer space could be used for military purposes. This led to the recognition by the international community of the need to put in place a minimal framework for the use of outer space for peaceful purposes.

Following resolutions passed in 1961 and 1962 concerning the peaceful uses of outer space, and a subsequent declaration setting out the principles governing the activities of states in outer space, five treaties were concluded by the United Nations through its Committee on the Peaceful Uses of Outer Space (COPUOS), which was established in 1959, and now form part of the corpus of international law governing outer space:

  1. the 1967 Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies (the Outer Space Treaty);
  2. the 1968 Agreement on the Rescue of Astronauts, the Return of Astronauts and the Return of Objects Launched into Outer Space (the Rescue and Return Agreement);
  3. the 1972 Convention on International Liability for Damage Caused by Space Objects (the Liability Convention);
  4. the 1974 Convention on Registration of Objects Launched into Outer Space (the Registration Convention); and
  5. the 1979 Agreement Governing the Activities of States on the Moon and Other Celestial Bodies (the Moon Agreement).

The UN space treaties establish rights and obligations between states parties to the treaties (the States Parties), which bear international responsibility for activities carried out by governmental entities, such as national space agencies, as well as commercial entities such as launch service providers, satellite operators, participants in outer space activities and entities conducting other activities in outer space.

The UN space treaties do not directly create obligations on non-governmental entities and it is at the discretion of States Parties to flow some of the obligations under the UN space treaties, such as responsibility and liability in case of damages, down to private commercial parties through the adoption of national space legislation or licensing regimes, or both.

At the international level, four of the five UN space treaties have been widely ratified.2 The exception is the Moon Agreement3 for the reasons discussed in subsection v. States with launch service capability or with an established national space industry, or both, have ratified the four space treaties.

i Outer Space Treaty

The Outer Space Treaty establishes fundamental rules and principles that govern the exploration and use of outer space. The preamble of the Outer Space Treaty recognises the 'common interest of all mankind in the progress of the exploration and use of outer space'4 and sets out that activities should be carried out 'for the benefit of all peoples irrespective of the degree of their economic or scientific development'5 to 'contribute to broad international cooperation'6 that can lead to 'the development of mutual understanding and to the strengthening of friendly relations between States and peoples'.7

The States Parties to the Outer Space Treaty must comply with its key principles:

  1. that outer space, including the Moon and other celestial bodies, shall be 'for the province of all mankind';8
  2. that the use of outer space, including the Moon and other celestial bodies, shall be 'without discrimination of any kind';9
  3. that outer space, including the Moon and other celestial bodies, are not subject to appropriation;10
  4. that activities in outer space are to be carried out in accordance with international law;11
  5. that outer space will be used for peaceful purposes, banning the establishment of military bases and installation and the testing of weapons;12
  6. that States Parties have international responsibility for national activities carried out by both governmental and non-governmental entities and the obligation to authorise and continuously supervise national activities;13
  7. that there is international liability for damage caused by a State Party that 'launches or procures the launching of an object into outer space'14 (the Launching State);
  8. that a State Party will have jurisdiction and control over a space object that it registers on its national registry;15
  9. the principle of cooperation and mutual assistance and the obligation on a State Party to carry out activities with 'due regard to the corresponding interests of all other States Parties';16 and
  10. that activities must not lead to the harmful contamination of outer space or to the environment of the Earth that may result from the 'introduction of extraterrestrial matter'.17

Many of these principles are now considered to be customary international law.

ii Liability Convention

The Liability Convention expands on Article VII of the Outer Space Treaty and introduces definitions for 'space object', 'launching', 'launching State' and 'damage'.

Articles II and III of the Liability Convention establish two concepts of liability:

  1. absolute (strict) liability for damage 'on the surface of the Earth or to aircraft in flight'; and
  2. fault-based liability for damage caused 'elsewhere than on the surface of the Earth'.

Liability is imposed on the Launching State of a space object that causes damage. There can be several Launching States. Under Article 1(c) of the Liability Convention, a Launching State includes a state:

  1. that launches a space object;
  2. that procures the launching of a space object;
  3. from whose territory a space object is launched; and
  4. from whose facility a space object is launched.

Article V establishes joint and several liability for any damage caused by a space object launched by two or more states.

Dispute resolution under the Liability Convention, its practicalities and alternatives

The definition of 'damage' under Article I(a) of the Liability Convention only extends to physical damage and it is unclear if compensation for damage under Article XII of the Liability Convention extends to indirect damage, such as loss of commercial revenues. The concept of 'fault' under Article III of the Liability Convention is also difficult to prove when damage occurs elsewhere than on the surface of the Earth.

In terms of the dispute resolution procedure set forth under the Liability Convention, a claim for compensation for damage must first be presented through diplomatic channels or through the UN Secretary-General.18 However, there is no requirement for the prior exhaustion of domestic remedies.19

Pursuant to the Liability Convention, if the relevant State Party (of the nation experiencing damage) does not present a claim for damage, another State Party may present a claim in respect of damage sustained in its territory by a person.20 Should neither the state of nationality nor the state where the damage occurred present a claim, then the state of permanent residence of the damaged person or entity may present a claim.21 This will all be subject to the condition that the injury or damage is not to a national of the Launching State or to someone who is operating the space object.22

The statute of limitations for bringing a claim is one year following the date of the occurrence of the damage or the identification of the liable Launching State.23 If a settlement of the claim cannot be achieved through diplomatic negotiations within a year, the concerned States Parties are required to establish a Claims Commission,24 which will make its decision and determine the amount of compensation payable based on the merits of the claim.25 However, the Claims Commission's decision is only final and binding 'if the parties have so agreed'; otherwise, it will render a final and recommendatory award that the parties are required to 'consider in good faith'.26

An alternative is for a UN Member State to bring the case before the International Court of Justice (ICJ). However, this requires the exhaustion of all local remedies and the ICJ's adjudication power is restricted unless the states (both claimant and defendant states) accept the jurisdiction of the ICJ.

Another alternative is to bring the case before the Permanent Court of Arbitration (PCA) and rely on the Optional Rules for Arbitration of Disputes Relating to Outer Space Activities (the PCA Space Rules).27 This allows the claiming parties to choose the size of the arbitration panel,28 invoke confidentiality 29 and designate the law or rules of law applicable to the substance of the dispute.30 Most importantly, the PCA Space Rules can be relied on not only by states and IGOs but also private entities. Another distinguishing factor is that the awards under the PCA Space Rules are final and binding.31

To date, there have been no cases before an international tribunal on international space law.

iii Registration Convention

The Registration Convention obliges a Launching State (as defined in the Liability Convention) to register a space object in 'an appropriate registry which it shall maintain'. This refers to an appropriate national registry,32 which should be established by the Launching State. The relevant Launching State is obliged to supply the UN Secretary-General with information concerning the space object 'as soon as practicable'.33 Where there is more than one Launching State, the states are required to 'jointly determine' which one of them is to register the space object.34 The state that registers the space object in its registry shall retain jurisdiction and control over the object in accordance with Article VIII of the Outer Space Treaty.

Transfer of space objects

Neither the Registration Convention nor any other UN space treaty provides for the transfer of a space object from the national registry of one state to the national registry of another state. This may be required, for example, in relation to the acquisition of an object or the merger or acquisition of a company. Such transfers must therefore, where possible, be dealt with through bilateral or multilateral agreements of the states concerned.

iv Rescue and Return Agreement

During the Cold War, the Soviet Union and the United States identified the need for a humanitarian framework to deal with the return of astronauts to their domicile and attempt to deal with the fear of mistreatment or hostage keeping. This led to the Rescue and Return Agreement, which sets out duties for States Parties to assist one another in the rescue and return of astronauts as well as space objects.

The Outer Space Treaty provides astronauts with a special status as 'envoys of mankind'35 and they are to be given 'all possible assistance in the event of accident, distress, or emergency landing'.36 The Rescue and Return Agreement departs from the notion of envoys of mankind and instead refers to 'personnel of spacecraft'.

Under the Rescue and Return Agreement, a State Party is required to:

  1. immediately notify the relevant Launching State and the UN Secretary-General when it becomes aware of personnel of a spacecraft who have suffered an accident, are experiencing conditions of distress or who have made an emergency or unintended landing under its jurisdiction or on the high seas;37 and
  2. immediately take possible steps to rescue such personnel and render all necessary assistance.38

The Rescue and Return Agreement also mandates the return of space objects to the relevant Launching State. State Parties to the Rescue and Return Agreement have an obligation to notify the Launching State of the space object when they discover any space objects or their component parts that have returned to the Earth.39 On the request of the Launching State of the space object, the State Party having jurisdiction over the territory on which the space object has been discovered is required to 'take such steps as it finds practicable to recover the object';40 return or hold the space object at the disposal of representatives of the Launching State, which shall furnish identifying data prior to its return;41 and eliminate the possible danger of harm.42 The expenses incurred in recovering and returning a space object are to be borne by the Launching State.

As at April 2018, the total number of recovered space objects notified to the UN Secretary-General was around 140 objects and around 4,000 small particles.43

v Moon Agreement

Article II of the Outer Space Treaty sets out the principle of non-appropriation, which states that 'outer space, including the Moon and other celestial bodies, is not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means'.44 This is repeated in Article 11(2) of the Moon Agreement.

The Moon Agreement, however, creates legal uncertainty by introducing a framework for the exploitation of the natural resources of the Moon and other celestial bodies as it is not clear whether the prohibition under Article II of the Outer Space Treaty extends to the appropriation of resources contained within celestial bodies (i.e., which can be extracted).

What distinguishes the Moon Agreement from the other four UN space treaties is that it introduces the concept that the Moon and its natural resources are the 'common heritage of mankind',45 which is a principle that originates from the 1982 UN Convention on the Law of the Sea in relation to the exploitation of mineral resources in the deep seabed.

The Moon Agreement also sets out that States Parties are to establish an international regime to govern the exploitation of the natural resources of the Moon and other celestial bodies when 'such exploitation is about to become feasible'.46 Pursuant to Article 11(7) of the Moon Agreement, the main purposes of this international regime to be established shall include:

  1. the 'orderly and safe development of the natural resources of the Moon';47
  2. the 'rational management of those resources';48
  3. the 'expansion of opportunities in the use of those resources';49 and
  4. an 'equitable sharing by all States Parties in the benefits derived from those resources, whereby interests and needs of the developing countries, as well as the efforts of those countries which have contributed either directly or indirectly to the exploration of the Moon, shall be given special consideration'.50

Many states see the notion of equitable sharing under Article 11(7)(d) of the Moon Agreement as a hindrance to the exploitation of natural resources of the Moon and other celestial bodies. As a consequence, the Moon Agreement, unlike the other UN space treaties, has not been widely adopted by states and, to date, has not been signed or ratified by any of the major spacefaring nations such as the United States, China or Russia.

III Principles adopted by the General Assembly

In addition to the UN space treaties noted in Section II, the UN General Assembly has adopted a series of declarations and principles relating to the exploration and use of outer space, namely the:

  1. Declaration of Legal Principles Governing the Activities of States in the Exploration and Uses of Outer Space 1963;
  2. Principles Governing the Use by States of Artificial Earth Satellites for International Direct Television Broadcasting 1982;
  3. Principles Relating to Remote Sensing of the Earth from Outer Space 1986 (the Remote Sensing Principles);
  4. Principles Relevant to the Use of Nuclear Power Sources in Outer Space 1992; and
  5. Declaration on International Cooperation in the Exploration and Use of Outer Space for the Benefit and in the Interest of All States, Taking into Particular Account the Needs of Developing Countries 1996.

The principles adopted by the General Assembly reflect and supplement those set out in the UN space treaties. Common themes include the need to conduct activities in and relating to outer space in the interests of all states, the need to act in accordance with international law, the importance of cooperation and mutual assistance, and the international responsibility of states for their national activities in and relating to outer space.

The Remote Sensing Principles are particularly significant given the rise of commercial Earth observation satellite activities, including the commercialised distribution of Earth observation data. The Remote Sensing Principles create important distinctions between primary data (raw data acquired by remote sensors and transmitted to the Earth from space), processed data (results of the processing of primary data into a usable form) and analysed information (information resulting from the interpretation of processed data). These distinctions have been adopted by regulatory bodies in their laws and policies relating to the ownership and dissemination of Earth observation data.

IV International Space Station

There are other agreements between states that govern more specific issues such as activities on the International Space Station (ISS).

The following specific instruments govern the conduct of astronauts on board the ISS:

  1. an Intergovernmental Agreement concerning cooperation on the civil International Space Station between the governments of Canada, Japan, Russia, USA and the Member States of the European Space Agency 1998 (the ISS Agreement);
  2. four memoranda of understanding between NASA and (1) the Canadian Space Agency, (2) the European Space Agency, (3) the government of Japan and (4) the Russian Space Agency (the ISS MOUs); and
  3. the Code of Conduct for the International Space Station Crew (CCOC).

The ISS MOUs set out that each 'Partner State' to the ISS must approve the CCOC before it provides space station crew. The CCOC establishes a chain of command on-orbit, a clear relationship between ground and on-orbit management, management hierarchy, standards for work and activities in space, and disciplinary regulations. It also provides the ISS Commander with appropriate authority and responsibility.

According to the ISS MOUs, the crew operates as one integrated team with one ISS Commander, who is responsible for the mission programme implementation and crew safety assurance on board the ISS.

Crew disciplinary policy is developed by the Multilateral Crew Operations Panel, which also has the power to address violations of the CCOC and impose disciplinary measures. This policy applies to any person approved for flight to the ISS, including both expedition crew and visiting crew, from the moment each is assigned a specific mission until the post-flight activities related to the mission is completed.

The ISS Commander is the highest authority among the ISS crew members on-orbit. The ISS Commander is in charge of on-orbit management and the flight director is in charge of ground management. The ISS Commander works under the direction of the flight director and in accordance with the flight rules. However, the ISS Commander is entitled to change the daily routine of the ISS crew members to address contingencies, perform urgent work associated with crew safety and the protection of ISS elements or conduct critical flight operations. Otherwise, the ISS Commander should implement the mission as directed by the flight director.

V Future of the UN space treaties

Although many countries recognise the need to update the UN space treaties to reflect emerging innovative activities such as space debris removal, in-orbit servicing and space resources utilisation, decision-making in COPUOS requires consensus among all Member States. As at 2019, there are 95 members of COPUOS,51 which means that harmonised understanding is hard to achieve in the subcommittee meetings. It is therefore unlikely that another treaty will be drafted and negotiated in the near future, or that the current UN space treaties will be updated.

However, guidelines on the long-term sustainability of outer space activities have been developed during COPUOS subcommittee meetings.


1 Joanne Wheeler MBE is the managing partner and Vicky Jeong is an associate at Alden Legal Limited.

2 As at 1 January 2020, 110 states have ratified, accepted or approved accession or succession to the Outer Space Treaty and 23 states have signed the Outer Space Treaty; 98 states have ratified, accepted or approved accession or succession to the Liability Convention and 23 states have signed the Liability Convention; 69 states have ratified, accepted or approved accession or succession to the Registration Convention and three states have signed the Registration Convention; and 98 states have ratified, accepted or approved accession or succession to the Rescue and Return Agreement and 23 states have signed the Rescue and Return Agreement.

3 As at 1 January 2020, 18 states have ratified, accepted or approved accession or succession to the Moon Agreement and four states have signed the Moon Agreement.

4 Preamble of the Outer Space Treaty.

5 ibid.

6 ibid.

7 ibid.

8 Article I of the Outer Space Treaty.

9 ibid.

10 Article II of the Outer Space Treaty.

11 Article III of the Outer Space Treaty.

12 Article IV of the Outer Space Treaty.

13 Article VI of the Outer Space Treaty.

14 Article VII of the Outer Space Treaty.

15 Article VIII of the Outer Space Treaty.

16 Article IX of the Outer Space Treaty.

17 ibid.

18 Article IX of the Liability Convention.

19 Article XI of the Liability Convention.

20 Article VIII(2) of the Liability Convention.

21 Article VIII(3) of the Liability Convention.

22 Article VII of the Liability Convention.

23 Article X(1) of the Liability Convention.

24 Article XIV of the Liability Convention.

25 Article XVIII of the Liability Convention.

26 Article XIX(2) of the Liability Convention.

27 Optional Rules for Arbitration of Disputes Relating to Outer Space Activities, Effective 6 December 2011,

28 Articles 5 to 10 of the PCA Space Rules.

29 Article 17(6) of the PCA Space Rules.

30 Article 35(1) of the PCA Space Rules.

31 Articles 34(2) and 38 of the PCA Space Rules.

32 Article II(1) of the Registration Convention.

33 Article IV of the Registration Convention.

34 Article II(2) of the Registration Convention.

35 Article V of the Outer Space Treaty.

36 ibid.

37 Article 1 of the Rescue and Return Agreement.

38 Article 2 of the Rescue and Return Agreement.

39 Article 5(1) of the Rescue and Return Agreement.

40 Article 5(2) of the Rescue and Return Agreement.

41 Article 5(3) of the Rescue and Return Agreement.

42 Article 5(4) of the Rescue and Return Agreement.

43 Information furnished during the IISL/ECSL Symposium on 'the 50th Anniversary of the Rescue and Return Agreement: Relevance and Challenges' on 9 April 2018:

44 Article II of the Outer Space Treaty.

45 Article 11(1) of the Moon Agreement.

46 Article 11(5) of the Moon Agreement.

47 Article 11(7)(a) of the Moon Agreement.

48 Article 11(7)(b) of the Moon Agreement.

49 Article 11(7)(c) of the Moon Agreement.

50 Article 11(7)(d) of the Moon Agreement.

Joanne Wheeler MBE 

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