5.3.1 Ordinary Meaning

Article 31 of the Vienna Convention on the Law of Treaties reads, ‘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.’ The first step in our interpretation therefore concerns the ‘ordinary meaning’ of the terms. We begin with Article I of the OST, which reads in full,

On its own, ordinary meaning provides little guidance for interpreting Article I. It does not tell us whether ‘use’ includes the extraction of Space resources, nor whether ‘use’ can be exclusive to a single actor – although there are words in Article I that at least suggest otherwise, i.e. ‘shall be carried out for the benefit and in the interests of all countries, irrespective of their degree of economic or scientific development, and shall be the province of all [hu]mankind’. Nor does ordinary meaning tell us whether property rights can be acquired over extracted Space resources. Again, this last issue is the one under debate.

We turn now to Article II, where the term of greatest relevance is ‘national appropriation’: ‘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.’Footnote ³² There is no ordinary meaning for ‘national appropriation’, since the term is not used elsewhere in international law, or in day-to-day conversation. We do not know whether it means title to territory, or simply the use of an object or area by one state to the exclusion of others. As a result, this first stage of interpretation – ‘ordinary meaning of the terms’ – does not take us very far.

5.3.2 The Context of the Terms

We turn to the second stage of our interpretation, namely the ‘context’ of the terms being interpreted. According to the Vienna Convention, context includes the text of a treaty, its preamble and its annexes. With regard to the text of the OST, there are several provisions that might inform the interpretation of Articles I and II. The first of these is Article VI, the only provision of the OST to address the issue of non-state actors:

‘Non-governmental entities’ will include international organisations, non-profit groups and private companies. But while mining is one possible profit-oriented activity that companies might pursue in Space, there are many others, including the use of satellites for communications – an activity that was already taking place at the time the OST was under negotiation and would therefore have been in the minds of the negotiators. The combination of Article VI with the possibility that Space mining could be conducted by non-governmental entities does not, on its own, make possible the acquisition of property rights. Indeed, there is nothing in Article VI that would either support or preclude this conclusion. Article VI simply makes states responsible for whichever Space activities their nationals, including private companies, undertake (as well as any activities of non-nationals on their territory or in spacecraft registered by them).

Then there is Article IX of the OST, which reads in full,

Article IX requires that states ‘conduct all their activities in outer space, including the moon and other celestial bodies, with due regard to the corresponding interests of all other States Parties to the Treaty’.Footnote ³⁵ However, there is no indication as to the level of care that ‘due regard’ requires. Is the obligation only to avoid reasonably foreseeable harm? Or is a higher standard of care required?

Article IX also foresees that some Space activities will have the potential to cause harmful contamination or interference, and it guards against these risks with a duty of consultation. However, there is no indication as to whether a state might be required to adjust its plans because of consultations. Nor does Article IX say anything, anywhere, about property rights.

Article 31 of the Vienna Convention indicates that the preamble is also part of the context for the purposes of treaty interpretation. The preamble of the OST reads, in full,

We see nothing in the preamble of the OST that supports or precludes the acquisition of property rights over extracted resources. The negotiators believed that the exploration and use of Space should benefit all peoples, but property rights are not necessarily incompatible with this belief.

5.3.3 Object and Purpose

The third step in a treaty interpretation is to examine whether the ‘object and purpose’ of the treaty cast any ‘light’ on the ordinary meaning of its terms. The most important evidence of a treaty’s object and purpose is usually found in its preamble, which is reproduced directly above. It is clear from the preamble that the overall object and purpose of the OST is the promotion of peace and international co-operation in Space – something which property rights might, depending on the circumstances, either strengthen or weaken. In other words, the object and purpose provide no guidance to our interpretation.

5.3.4 Subsequent Agreement

We must now consider any ‘subsequent agreement’ or ‘subsequent practice’ establishing ‘the agreement of the parties regarding’ the interpretation of the OST, with Article 31(3)(a) and (b) of the Vienna Convention on the Law of Treaties reading,

One possible subsequent agreement of relevance is the 1979 Agreement Governing the Activities of States on the Moon and Other Celestial Bodies (‘Moon Agreement’),Footnote ³⁸ which Steven Freeland and Ram Jakhu argue provides some support for an interpretation of Article II OST in favour of the ‘exploitation’ of extracted resources not constituting ‘national appropriation’:

However, the most relevant aspect of the Moon Agreement regarding the issue of resource exploitation would seem to be the deferral of negotiations on the issue until some later date. In our view, this deferral suggests not the existence of ‘any agreement between the parties regarding the interpretation of the treaty or the application of its provisions’, but rather an absence thereof. We therefore conclude that the Moon Agreement is of no assistance to our interpretation of the OST.

5.3.5 Subsequent Practice

We turn now to ‘any subsequent practice in the application of the treaty which establishes the agreement of the parties regarding its interpretation’. Since Space mining as such has not yet taken place, there is very little to look at here – apart from the fate of a few lunar samples. In 1993, Sotheby’s auctioned three moon rocks for $442,500.Footnote ⁴⁰ The rocks had been collected by the Soviet Union’s robotic Luna-16 mission in 1970 and given to the widow of Sergei Pavlovich Korolev, the former director of the Soviet Space programme, in his honour.Footnote ⁴¹ Two decades later, they somehow found their way to Sotheby’s. The same rocks were auctioned again in 2018, this time for $855,000. However, there is no indication that the Soviet or Russian governments approved these sales, making them of little value as ‘subsequent practice’ establishing the ‘agreement of the parties’ regarding the interpretation of the OST.

In 2012, the US Congress granted former crew members of the Mercury, Gemini and Apollo programmes full ownership rights over equipment and spacecraft parts they had saved as souvenirs. However, the legislation specifically excluded ‘lunar rocks and other lunar material’.Footnote ⁴² As an action taken by a national government, this exclusion would seem to be relevant as subsequent practice, but it is an isolated case. Five years later, in 2017, a bag containing a few particles of Moon dust was auctioned at Sotheby’s for $1.8 million.Footnote ⁴³ The bag, used by Neil Armstrong to collect lunar samples in 1969, was lent by NASA to a Space museum in Kansas. The bag then went missing and, years later, was misidentified and sold for just $995. When NASA found out what had happened, it challenged the purchaser’s ownership, which led to litigation, a ruling against NASA, and ultimately the $1.8 million sale. It all makes for a great story, but there is no relevant subsequent practice here. NASA was not arguing that it did or did not have property rights over the lunar dust. It was simply arguing that the bag had been illegally acquired.

5.3.6 Negotiating Records

Our analysis above leads to the conclusion that the issue of property rights is not addressed in the OST. Having reached this stage, we can now review the negotiating record of the treaty to confirm our interpretation but not to overturn it, as Article 32 of the Vienna Convention explains:

There was very little debate on Article II during the negotiation of the OST, probably because the provision was adopted almost verbatim from Article 3 of the 1963 United Nations General Assembly ‘Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space’, which reads, ‘Outer space and celestial bodies are not subject to national appropriation by claim of sovereignty, by means of use or occupation, or by any other means.’Footnote ⁴⁵

The only change made to this text in the 1967 OST was the insertion of the words ‘including the moon and other celestial bodies’ after the term ‘outer space’, in recognition of the fact that all celestial bodies – including potentially mineral-rich asteroids – are part of Space and not distinct from it. The same change was made in Article I of the OST. As a result, the Moon, asteroids and other planets are all subject to the freedom of ‘exploration and use’ and other provisions of the treaty, in addition to the prohibition on national appropriation.

Despite the near absence of debate, an examination of the negotiating records (travaux préparatoires) reveals several interventions of relevance.Footnote ⁴⁶ During a meeting of COPUOS on 13 July 1966, an Austrian delegate expressed the view that a proper differentiation was required between ‘non-appropriation’ and ‘use’. He suggested that the text ‘should go further and should regulate not only the exploration of the moon and other celestial bodies but also their use; that would obviate any contradiction between the terms “non-appropriation” and “use”.’Footnote ⁴⁷

On 4 August 1966, a Belgian delegate said that he had ‘taken note of the interpretation of the term “non-appropriation” advanced by several delegations – apparently without contradiction – as covering both the establishment of sovereignty and the creation of titles to property in private law.’Footnote ⁴⁸

Ultimately, negotiations on the issue of ‘extracting minerals’ were deferred to some indefinite future date (i.e. after the conclusion of the OST), as the following exchange between French and Soviet delegates on 20 October 1966 made clear:

As a conclusion to this section, we note that a full and systematic treaty interpretation, carried out in accordance with the customary international law codified in Articles 31 and 32 of the Vienna Convention on the Law of Treaties, supports the view that the OST does not address – and was not intended to address – the issue of property rights over extracted Space resources. Rather, the issue was left until later, when Space mining had become a real prospect and the challenges involved were better understood.

A decade later, the initiation of negotiations leading to the 1979 Moon Agreement provided further confirmation that this was the intended approach. The preamble to the Moon Agreement acknowledges the ‘benefits which may be derived from the exploitation of the natural resources of the moon and other celestial bodies’ and the ‘need to define and develop the provisions’ of the four main Space treaties (the OST,Footnote ⁵¹ the Rescue Agreement,Footnote ⁵² the Liability ConventionFootnote ⁵³ and the Registration ConventionFootnote ⁵⁴) ‘having regard to further progress in the exploration and use of outer space’.

Indeed, the proposal that led to the negotiations, submitted to COPUOS by a representative from Argentina, Dr Aldo Armando Cocca, argued that the OST was deficient because it did not specifically regulate the use of the Moon’s natural resources.Footnote ⁵⁵

The need for negotiations on Space mining was accepted by all the members of COPUOS, which operates on consensus, as well as all the members of the UN General Assembly, which adopted the Moon Agreement without a vote (i.e. by consensus) in 1979.Footnote ⁵⁶ The fact that only 18 states subsequently ratified the Moon Agreement does not detract from this point, since decisions to refrain from ratifying usually concern the specific provisions of a treaty and not the general need for a treaty on the subject matter in question.

As mentioned above, the Moon Agreement itself does not provide a detailed set of rules for Space mining. Instead, it declares the Moon and other celestial bodies the ‘common heritage of [hu]mankind’ and provides a mechanism for initiating a multilateral negotiation on an ‘international regime … to govern the exploitation of the natural resources of the moon as such exploitation is about to become feasible’ (Article 11(5)). According to Article 18, such a negotiating conference can be called ‘at the request of one third of the States Parties to the Agreement and with the concurrence of the majority of the States Parties’.

Although the Moon Agreement was clearly intended to open the door to Space mining, the United States began opposing the new treaty shortly after its adoption,Footnote ⁵⁷ as well as any other efforts to address the issue through multilateral negotiations. It adopted an alternative strategy of creating more ‘subsequent practice’ in favour of its position, which is that the OST does not preclude property rights over extracted resources, and that in the absence of international rules on the conduct of Space mining, these activities may be regulated solely through national laws. Again, the US position is not untenable, but this is hardly the end of the matter.

Our concerns are not with the US interpretation of the OST, but with the assumption that regulating Space mining solely through national laws is an appropriate approach, given the existence of serious risks, global interests and the possible emergence of flag-of-convenience states. We are also concerned that the United States and companies incorporated there could be uniquely positioned to shape the development of rules of customary international law on the conduct of Space mining, rules that could be heavily influenced by corporate interests and would be binding on most, if not all, states.

5.4.1 Commercial Space Launch Competitiveness Act

Sponsored by Republican Senators Ted Cruz and Marco Rubio and signed by Democratic president Barack Obama, the 2015 Commercial Space Launch Competitiveness Act gives US citizens and companies the right to ‘possess, own, transport, use, and sell [any] asteroid resource or space resource obtained in accordance with applicable law, including the international obligations of the United States’.Footnote ⁶⁰ The legislation thus claims to be consistent with international law, though it does not necessarily take the interests of all countries into account.

The Commercial Space Launch Competitiveness Act was designed to bolster the United States’ preferred interpretation of the OST and support US companies such as Planetary Resources, which, while now defunct, lobbied hard for this legislation.Footnote ⁶¹ As Brian Israel, one of the State Department lawyers involved in the legislation, later argued, ‘Absent international consensus on what the rule is, national legislatures are in the position of weighing in on one side or another of an unresolved interpretive debate’.Footnote ⁶²

Sometimes, national legislation can indeed help to clarify the interpretation of a treaty provision. Again, Article 31(3)(b) of the Vienna Convention on the Law of Treaties reads,

However, no single state can develop international law on its own. For this reason, it helps the US interpretive effort that three countries have demonstrated support for its position by adopting similar domestic laws. In 2017, Luxembourg adopted legislation on commercial Space mining and offered subsidies to Space mining companies that incorporate there.Footnote ⁶⁴ In 2019, the United Arab Emirates (UAE) adopted a law that foresees commercial Space mining, while postponing the creation of a licensing regime.Footnote ⁶⁵ In 2021, Japan adopted a ‘Law Concerning the Promotion of Business Activities Related to the Exploration and Development of Space Resources’, under which Japanese companies may seek permission from the Japanese government to extract and use Space resources.Footnote ⁶⁶

One can understand why these states have become ‘first movers’ on this new economic frontier. The United States is the centre of ‘NewSpace’, with thousands of large and small companies focused on developing and generating profit from new technologies and applications. Luxembourg has long provided a comfortable corporate home to the two largest operators of geosynchronous communications satellites, while the UAE is seeking to diversify its oil-based economy. It already operates three Earth observation satellites as well as a scientific probe named Hope that orbits Mars and collects data on that planet’s atmosphere. The Japanese government, for its part, has long engaged in Space exploration, including on the International Space Station, and is now seeking to develop a globally competitive Space industry. One Japanese company, ispace, welcomed the new law with an ambitious statement of intent: ‘This means that companies of Japanese nationality may operate continuously in a fixed location on the Moon for the purposes of mining or extraction, storage, processing, and other operations necessary for the development of space resources, as well as to freely use space resources.’Footnote ⁶⁷ By adopting national legislation, all four states aim to provide companies and investors with some of the certainty they need to develop the expensive technologies and infrastructure required for Space mining.

However, Article 31(3)(b) of the Vienna Convention on the Law of Treaties includes the words ‘which establishes the agreement of the parties’. Four states cannot, on their own, establish the agreement of the parties regarding the interpretation of a treaty, like the OST, that has been ratified by 110 states. Moreover, as with state practice in customary international law, ‘subsequent practice’ in treaty interpretation also includes the reactions of the other parties. How many states have expressed support for the US position? How many have expressed concerns, for instance, during meetings of COPUOS? How many have indicated a preference for a widely multilateral rather than unilateral or bilateral approach to the issue of Space mining? Although the United States, Luxembourg, the UAE and Japan have adopted legislation, what matters, more than these four instances of subsequent practice, is how the rest of the parties to the OST respond.

Again, it is important to recognise that the Commercial Space Launch Competitiveness Act is part of a deliberate effort to advance a particular interpretation of the OST. As Philip De Man cogently explains,

De Man also explains how a power imbalance between spacefaring states on the one hand, and non-spacefaring states on the other, raises a serious issue as to how we treat ‘subsequent practice in the application of the treaty’. We can draw a parallel here with the role of power in the development and change of customary international law. Indeed, one of the authors of this book has argued that the actions and statements of less powerful states should be accorded disproportionate weight as state practice and evidence of opinio juris – the subjective element of customary international law – because taking positions in opposition to powerful states can entail ‘costs’ and doing so therefore indicates strong commitments to those positions.Footnote ⁶⁹

Further to this, De Man makes the important point that the OST is not a regular treaty. Instead, the OST and the other multilateral Space treaties contain ‘fundamental principles’ that ‘concern all States, and indeed the whole of humanity’.Footnote ⁷⁰ For this reason, De Man argues,

De Man finds support for his position in the first report of the United Nations International Law Commission’s Working Group on Subsequent Agreements and Practice in Relation to the Interpretation of Treaties. According to the working group, ‘the interpretation of treaties which establish rights for other States or actors is less susceptible to “authentic” interpretation by their parties’.Footnote ⁷² De Man goes so far as to argue that the second paragraph of Article I, and Article II, of the OST create obligations erga omnes, i.e. obligations owed ‘towards the international community as a whole’,Footnote ⁷³ a category of rules that is well recognised in international law.Footnote ⁷⁴

To be clear, De Man is not arguing that the parties to the OST are unable to collectively modify its provisions, either formally through negotiations or informally through subsequent practice. His argument, instead, is that the subsequent practice of a small subset of the parties should not and cannot be treated as sufficient. The merit in this argument becomes apparent if we read the two provisions carefully again.

Article I, second paragraph:

Article II:

The second paragraph of Article I recognises rights held by ‘all States … on a basis of equality’, while Article II maintains the internationalised character of Space against any effort to assert title, including by actions of a kind – ‘use and occupation’ – that could only be taken by powerful spacefaring states. All this leads De Man to conclude,

Although the United States’ position on the OST and Space mining is not untenable, and while it is seeking to strengthen its position and develop new rules of customary international law through its own practice and those of a small group of like-minded states, it is important to remember that a much larger number of states disagree, including the G77, China and Russia. It is possible that two camps will emerge on the issue of Space mining and international law in the future: the United States and its allies on one side, and Russia, China and the Global South on the other. Such a divide would both weaken the OST and preclude the development of new customary international law. In the circumstances, the only globally responsible way forward is to negotiate a new multilateral treaty on Space mining. Brian Israel, indeed, anticipates such a negotiation – at some future point:

The Commercial Space Launch Competitiveness Act has served an important, if unintended, purpose by drawing attention to these matters and mobilising voices in favor of a multilateral approach. Several expert groups and non-governmental organisations, representing a wide variety of stakeholders, have responded by proposing principles and frameworks for the multilateral governance of Space resources. For example, in November 2019, The Hague International Space Resources Governance Working Group adopted twenty ‘Building Blocks for the Development of an International Framework on Space Resource Activities’.Footnote ⁷⁹ This document advocates the establishment of an international framework which is consistent with international law, contributes to sustainable development, promotes and secures ‘the orderly and safe utilization’ of Space resources, and takes into ‘particular account’ the needs of developing states and science. In April 2020, the Outer Space Institute adopted the ‘Vancouver Recommendations on Space Mining’, which promote negotiations on a multilateral agreement that are open to all states.Footnote ⁸⁰ It was in the context of these calls for multilateral negotiations that the United States decided to push harder, both for its preferred interpretation of the OST, and for new rules and practices developed among a small group of like-minded states.

5.4.2 Executive Order and Artemis Accords

In April 2020, President Donald Trump signed an ‘Executive Order on Encouraging International Support for the Recovery and Use of Space Resources’ (see Figure 5.4).Footnote ⁸¹ The executive order (EO) reiterated that it is ‘the policy of the United States to encourage international support for the public and private recovery and use of resources in outer space, consistent with applicable law’. However, the EO went further than the 2015 Commercial Space Launch Competitiveness Act by explicitly rejecting that Space is a ‘global commons’ and dismissing the 1979 Moon Agreement as irrelevant because it has not been ratified by major spacefaring states. The EO also instructed the US State Department to take ‘all appropriate actions to encourage international support for the public and private recovery and use of resources in outer space’.Footnote ⁸²

Figure 5.4 From left to right: NASA Administrator Jim Bridenstine, President Donald Trump, VP Mike Pence and Second Lady Karen Pence watch a SpaceX Falcon 9 rocket launch NASA astronauts Robert Behnken and Douglas Hurley on 30 May 2020.

Credit: NASA (www.flickr.com/photos/nasahqphoto/49956153337/in/photostream).

Just one month later, in May 2020, NASA announced the core principles of the ‘Artemis Accords’, which it said would ‘establish a common set of principles to govern the civil exploration and use of outer space’.Footnote ⁸³ Then, in October of 2020, the full text of the Artemis Accords was released.Footnote ⁸⁴

The Trump administration clearly wanted the Artemis Accords to provide strong support for the US position that the OST does not preclude property rights over extracted resources, and that in the absence of international rules on the conduct of Space mining, these activities may be regulated solely through national laws. NASA negotiated bilaterally with NASA partner states, with these being the states most likely to support the US position. Yet the Artemis Accords as ultimately adopted carry less weight, as subsequent practice, than NASA might have hoped. Although Australia, Canada, Italy, Japan, Luxembourg, the UAE and the UK all signed the document in an online ceremony at the International Astronautical Congress in October 2020, the text explicitly states that the Artemis Accords ‘represent a political commitment’. In other words, they do not constitute a multilateral treaty or even a series of bilateral treaties. For this reason, the Artemis Accords are not that significant as ‘subsequent practice in the application of the treaty which establishes the agreement of the parties regarding its interpretation’, or as state practice and evidence of opinio juris for the purposes of customary international law.

The text of the Artemis Accords also includes a sentence in Section 10(2) that reads,

The language used in this sentence differs from that used in the ‘Artemis Principles’ as released by NASA in May 2020, before the negotiations with NASA partner states began. There, NASA simply asserted, ‘The Artemis Accords reinforce that space resource extraction and utilization can and will be conducted under the auspices of the Outer Space Treaty, with specific emphasis on Articles II, VI, and XI.’ Although NASA was likely pushing for a similar statement that Space mining does not constitute ‘national appropriation’, the insertion of the word ‘inherently’ into Section 10(2) of the final text of the Artemis Accords introduces an element of ambiguity that the US negotiators would not have sought. Is Space mining sometimes ‘national appropriation’ and sometimes not? Was Space mining originally not ‘national appropriation’, but capable of becoming understood as ‘national appropriation’ as understandings and interests change? Can a term such as ‘national appropriation’, which has no ‘ordinary meaning’ because it is not used outside the Outer Space Treaty, ‘inherently’ mean anything? The appearance of this term in the final text of the Artemis Accords most likely represents a negotiated compromise, and specifically a ‘constructive ambiguity’ designed to accommodate different views by fudging the terminology.Footnote ⁸⁶ The result, however, is to further reduce the weight of the Artemis Accords as subsequent practice, state practice and evidence of opinio juris.

Despite this ambiguity and their status as a ‘political commitment’, the Artemis Accords still had the effect of undermining the long and stable relationship of Space co-operation between Russia and the United States. The May 2020 announcement of the core principles of the Artemis Accords was quickly condemned by Dmitry Rogozin, the director general of Roscosmos, on Twitter: ‘The principle of the invasion is the same, be it the moon or Iraq. Create a coalition of the willing and then, without the UN or even Nato, move forward to the goal. But this will only result in a new Afghanistan or Iraq.’Footnote ⁸⁷ Two weeks later, in a radio interview, Rogozin spoke directly to the international law issue: ‘We will not, in any case, accept any attempts to privatize the Moon. It is illegal, it runs counter to international law.’Footnote ⁸⁸

China, for its part, did not offer an official response, although commentary in its state-run media described the Artemis Accords as a product of a Cold War mentality, focused on exerting dominance, and continuing the legacy of colonisation.Footnote ⁸⁹ There is no indication or expectation that China might participate in the US-led effort to develop a governance regime for Space mining through practice and bilateral instruments.

As for the states of the Global South, most of them likely shared the view – expressed officially by Rogozin and unofficially by the Chinese state-run media – that the Artemis Accords were just another exercise of American hegemony, this time led by the proudly unilateralist and undiplomatic Donald Trump. As we will see below, many of these states later took part in a ‘G77 and China’ statement strongly supporting the creation of a Working Group on Space Resources at COPUOS, a possible first step towards multilateral negotiations.

The United States is, however, continuing its effort to advance its preferred interpretation of the OST, and to build on it by creating rules and practices for Space mining through agreements and other ‘state practice’ co-ordinated among a small group of like-minded states. Thirteen additional states – Brazil, New Zealand, South Korea, Ukraine, Poland, Israel, Mexico, Romania, Bahrain, Colombia, Singapore, France and Saudi Arabia – have signed the Artemis Accords since October 2020. However, the most significant further step in the US effort involves a call for proposals, issued to the Space industry, for the extraction and sale of lunar regolith to NASA.

5.4.3 NASA Contracting to Purchase Lunar Regolith

In September 2020, NASA announced that it was seeking proposals from private companies to extract small amounts of regolith from the surface of the Moon and sell them to NASA. Any selected company would be required to collect between 50 and 500 grams and provide imagery of the material and data concerning its location. NASA would then buy the material, through an ‘in-place ownership transfer’, without the company having to return the sample to Earth. NASA might then retrieve the material at some unspecified future time.Footnote ⁹⁰ Or it might not.

None of this was about the regolith itself. NASA Administrator Jim Bridenstine admitted that the planned purchases were aimed at creating more subsequent practice in favour of the US interpretation of the OST: ‘What we’re trying to do is make sure that there is a norm of behavior that says that resources can be extracted and that we’re doing it in a way that is in compliance with the Outer Space Treaty’.Footnote ⁹¹ The admission was remarkable for its candour: government officials are rarely transparent about efforts to change international law through actions rather than negotiations, perhaps because it draws attention to their efforts and can generate pushback from other state and non-state actors.

In December 2020, NASA signed contracts with four companies: Lunar Outpost and Masten Space Systems from the United States, and the Japanese company ispace and its Luxembourg-based subsidiary ispace Europe.Footnote ⁹² It aims to complete the purchases of regolith by 2024.

5.5.1 Loss of Science Opportunities

Done well, Space mining could provide new science opportunities and unprecedented sampling of celestial bodies. For example, asteroids contain some of the oldest materials in the solar system, some of which have experienced little thermal processing since their incorporation into parent bodies. The Moon’s ice deposits are a partial record of volatile delivery to Earth.

Done poorly, Space mining would hinder science. For example, water and oxygen could in the future be extracted from astromaterials by pyrolysis.Footnote ⁹⁹ If systematic scientific sampling does not occur prior to their alteration or consumption, valuable information about the solar system could be lost, including information locked into cosmochemical or mineralogical signatures. A clear analogy exists on Earth where, in many jurisdictions, mining and construction companies are made to wait while archaeologists and biologists survey sites slated for development. A Space mining company’s own analysis will be designed to maximise resource yields and not science opportunities. These risks would only be exacerbated by inconsistent practices of the kind likely to result from national regulations that are not co-ordinated under some kind of multilateral regime.

5.5.2 Planetary Protection

Some of the first efforts at private Space exploration have manifested an incautious approach to risk avoidance. In 2019, the Israeli non-profit SpaceIL crashed a robotic lander on the Moon. Unbeknown to SpaceIL, its partner – the Arch Mission Foundation – had placed thousands of tardigrades on board.Footnote ¹⁰⁰ Tardigrades, commonly referred to as ‘water bears’ or ‘moss piglets’, are tiny (0.5 millimetre) eight-legged animals that are able to survive extreme temperatures, pressures and radiation, and even the vacuum of Space. In this instance, the act of putting life on the Moon is not the concern, thanks to the harsh environment on the lunar surface. Rather, the concern is that a non-governmental entity has already smuggled lifeforms onto a spacecraft destined for another celestial body.

In 2018, SpaceX launched a Tesla automobile on an orbit that extends past Mars. Although no impact with Mars is expected,Footnote ¹⁰¹ there was an initial lack of clarity on the mission profile and the potential for the unsterilised payload to encounter the Red Planet.Footnote ¹⁰² Unlike the Moon, the environment on Mars may allow certain forms of life to survive and become established. Careful precautions are therefore needed and should always involve full transparency and co-operation.

These examples of private risk-taking suggest that Space mining companies might take shortcuts too if not carefully regulated according to widely agreed rules. For example, they might choose not to fully sterilise equipment sent to Mars or other celestial bodies having conditions potentially favorable to life, thus contravening the international guidelines on planetary protection produced by the Committee on Space Research (COSPAR) and studiously followed by national Space agencies.Footnote ¹⁰³ One could even imagine a company disregarding the guidelines in order to experiment by introducing lifeforms to an alien environment, as occurred with rabbits in Australia, starlings in the United States and Canada Geese in the United Kingdom and New Zealand. It is, in addition, very easy to imagine Space mining companies failing to take the measures necessary to contain potentially dangerous dust and debris.

5.5.3 Dust and Debris Streams

Lunar dust, which is very fine and highly abrasive, is a known challenge to operations on the Moon. Any surface activity could exacerbate lunar dust migration, including by lofting dust onto trajectories that cross lunar orbits, such as that of NASA’s planned Lunar Gateway.Footnote ¹⁰⁴ Moreover, without co-operation from all actors, the limited number of useful lunar orbits could quickly become filled with Space debris, interfering with humanity’s access to the Moon.

On asteroids, limited gravity and low escape speeds will make it difficult to prevent the loss of surface material. Even if full enclosures are used, waste material might be purposefully jettisoned to reduce costs. Mining could also lead to uncontrolled outbursts of material due to volatile sublimation following the removal of surface layers or other processes.

Space mining will initially focus on the Moon and near-Earth asteroids, because of their accessibility. Asteroids on Earth-crossing orbits will be among the easiest to reach. Under certain conditions, the debris streams resulting from asteroid mining could contribute to the near-Earth meteoroid population and therefore threaten not only lunar operations but the thousands of satellites in Earth’s orbit that support essential civilian and military activities, ranging from banking, agriculture and aviation to search and rescue and reconnaissance.Footnote ¹⁰⁵ Even the dust from the Moon, if expelled at much higher than natural rates, could cause noticeable changes to the cis-lunar environment (which, as we explain in Chapter 7, is the region of Space between an altitude of 35,786 kilometres – where Earth’s geosynchronous orbit is located – and the area around the Moon).

Space missions already provide some evidence of such risks, although so far these remain at negligible levels. As mentioned, a small impactor was used to make a crater on Ryugu in 2019, during Japan’s Hayabusa-2 mission.Footnote ¹⁰⁶ Some of the anthropogenic meteoroids resulting from the impact could begin reaching Earth in 2033 during Ryugu’s next close approach to our planet.Footnote ¹⁰⁷ In September 2022, NASA tested its ability to deflect an asteroid by striking (65803) Didymos B (Dimorphos) with the Double Asteroid Redirection Test (DART) spacecraft. This impact will also have produced anthropogenic meteoroids, with the possibility in this case of immediate delivery to Earth.Footnote ¹⁰⁸ Again, while these risks are far less than those posed by existing meteoroids, they demonstrate that human actions can indeed change the near-Earth environment.

Nor are operational hazards the only consideration. For example, while dust launched into cis-lunar Space from the Moon might be too fine or too low in spatial density to pose a serious risk to spacecraft, at least compared to other hazards, it could, if launched in sufficient quantities, have implications for the brightness of Earth’s sky and therefore for astronomy due to scattered light. Since we are just now beginning to understand how dust is naturally distributed in cis-lunar Space,Footnote ¹⁰⁹ we are not yet at the point of considering its effects on sky brightness. But light pollution from satellites has emerged as a major concern, followed (most recently) by an awareness that light reflecting off orbital debris might also affect astronomy.Footnote ¹¹⁰

5.5.4 Asteroid Trajectory Changes

Some of the risks associated with Space mining are small in terms of statistical risk but very high in consequence. As Chapter 6 explains, over the next decade we can expect about 50 asteroids with diameters greater than 100 metres to pass within ten lunar distances of Earth, a handful of which are in the 1,000-metre size range.Footnote ¹¹¹ The positions and orbits of these asteroids are relatively well established and none of them poses any risk to us in this current century. However, these asteroids that approach closest to Earth are also the ones most likely to be selected for Space mining. Since removing mass from an asteroid will almost inevitably change its trajectory, any mining operations that are not fully informed by science could potentially lead to an Earth impact emergency. Do we trust profit-oriented companies, which seek to reduce costs wherever possible, to conduct the careful scientific assessments and calculations needed to guard against this low-risk, very-high-consequence outcome? Do we trust national regulators from individual states to maintain up-to-date requirements based upon the best available science and the precautionary principle, and to monitor and enforce compliance? What about flag-of-convenience states that may see economic advantage in having more relaxed standards or less rigorous enforcement? Clearly, multilateral rules and oversight are required.

5.5.5 Space Companies as Actors in International Law-Making?

The accessibility of Space is increasing as a growing number of actors develop or purchase the technologies needed to launch and operate satellites and other spacecraft. Alongside the growth in spacefaring states is an even faster growth in the number of Space companies. The result, one might think, could be a certain democratisation of the Space environment.

However, most of the growth in Space companies is centred in one country.Footnote ¹¹² This concentration of growth raises the possibility that the United States, as the launch and licensing state for most commercial Space activities, could be uniquely positioned to steer actual mining practice in support of its diplomatic efforts to secure broad acceptance among states that commercial Space mining is permissible under the OST. Such practice could further contribute to the development of customary international law standards for the conduct of mining operations.

This steering could happen in one of two ways, or even both. First, international Space law uniquely makes states responsible for the activities of companies incorporated within them. This feature might allow those activities to count both as ‘subsequent practice’ for the purposes of treaty interpretation, and as ‘state practice’, and even evidence of opinio juris, for the purposes of customary international law. This is due to Article VI of the OST, which is reproduced in full above, and only partly here:

The activities of most Space mining companies will comply from the outset with the laws, regulations and policy preferences of their state of incorporation, which again is likely to be the United States. In such a situation, one could – because of Article VI – understand the activities of the company as akin to those of an agent acting on behalf of the state. We note that a state can be legally accountable for the actions of actual agents, e.g. SpaceX when carrying NASA astronauts to the ISS under contract with that national Space agency, under the general rules of customary international law on state responsibility,Footnote ¹¹⁴ in parallel to (or even outside the scope of) Article VI.

In other situations, the laws, regulations and policy preferences of the state of incorporation might not yet be fully developed, in which case the activities of the company will either be met with acquiescence or prompt the state into adopting new rules or clarifying existing ones.Footnote ¹¹⁵ In the case of acquiescence, the activities of the company could be considered subsequent practice and state practice, since the state is thereby implicitly endorsing them. Activities that prompt the state to develop or reform its laws, in contrast, should not be so considered, because the state is responding in a manner that indicates a lack of endorsement. Instead, it is the adoption of new rules or the clarification of existing rules that is the relevant subsequent practice and state practice here. It may also provide evidence of opinio juris because it suggests a sense of obligation on the part of the state to bring its domestic law into compliance with developments in international law.

The second way that US steering could happen is that other states or foreign companies wishing to engage in Space mining might have little choice but to hire US companies, or to enter into joint ventures with them, in order to access technology or operational experience. As a result, their Space mining activities will then follow the laws and regulations of the United States.

There is a historical precedent for this. In the 1945 Truman Proclamation, the US government asserted that every coastal state has exclusive jurisdiction over the resources of the continental shelf off its coastline.Footnote ¹¹⁶ The claim, which was framed to be available to every coastal state, was soon repeated by many of them, leading to the rapid development of a new rule of customary international law and, just 13 years later, to its codification in the 1958 Convention on the Continental Shelf.Footnote ¹¹⁷ However, the reciprocally available character of the claim did more than attract the support of other states; it also worked to the advantage of US oil companies, which at the time were among the very few companies with offshore drilling technologies. As a result, most other coastal states could only exercise their newly recognised rights by partnering with a US oil company.Footnote ¹¹⁸ This situation also worked to the benefit of the US government, as overseas profits flowed home, and as US regulators found themselves regulating offshore drilling worldwide – via their regulatory powers over the US companies.

One can see a similar development currently in low Earth orbit (LEO), where SpaceX is occupying entire orbital shells under licences issued by the United States’ Federal Communications Commission (FCC) as it builds a mega-constellation of up to 40,000 satellites. As a result, the FCC has become the most important regulator in LEO, notwithstanding the international character of that zone. The various challenges associated with mega-constellations are discussed in Chapters 2 and 3.

There are, however, two factors that could impede the influence of the United States and US companies on the development of new rules for Space mining. The first is the incredible mobility of high-tech companies, which can be attracted to states with generous subsidies, lower taxes or more relaxed regulatory regimes. The second factor is China, which has recently developed into a major spacefaring state.

5.5.6 Fragmentation of the Space Law Regime

As mentioned, the interpretation of the OST preferred by the United States risks a race to the bottom and even the emergence of flag-of-convenience states. Allowing Space mining to take place under national regulations – subject, at the international level, only to an undefined duty to consult – would enable states that wished to attract mining companies to do so by offering minimal regulation and lax enforcement.

There are examples here on Earth that support our concerns. For example, three-quarters of the world’s terrestrial mining companies are incorporated in Canada, which exercises relatively little oversight of their operations in the Global South.Footnote ¹¹⁹ Inconsistencies among different national laws and regulations, along with weak enforcement, have led to human rights abuses, environmental damage and adverse health impacts. Meanwhile, in the maritime domain, flag-of-convenience states provide shipping companies with registrations for their vessels, as is required by international law, but do so with minimal regulation and lax enforcement. Not surprisingly, ships with flags of convenience have poor safety records.Footnote ¹²⁰ In Space, as we explain in Chapter 2, national regulation of corporate activities with little international involvement has already resulted in a debris crisis in LEO.

Established US companies such as SpaceX are unlikely to change their place of incorporation anytime soon, because of the frequent and often very large contracts they receive from NASA and the US Space Force. But the fact that Japan’s ispace has established a subsidiary in Luxembourg suggests that other Space companies are willing to ‘move’ elsewhere in pursuit of subsidies, tax breaks or favourable regulations. It is also interesting that this Luxembourg subsidiary, ispace Europe, was one of the four recipients of a NASA contract for the extraction and sale of lunar regolith, since this suggests a certain lack of concern about ‘regulatory flight’ on the part of the US government. However, awarding this one contract to a foreign company might also have been a calculated move to involve another country in what, according to the then NASA administrator, was nothing more than an effort to create a legal precedent.Footnote ¹²¹

Tax breaks and favourable regulation is one thing; little to no oversight is another. It is not difficult to imagine a national government seeking revenue through fees for incorporating Space companies or for registering spacecraft without making any serious effort to develop and enforce national laws and regulations. As we explain in Chapter 2, for example, Rwanda might be behaving as a flag-of-convenience state for the purposes of filings for radio spectrum at the International Telecommunication Union. We thus must ask whether a flag-of-convenience state would be acquiescing to all activities of one of its ‘national’ companies by failing to develop or enforce meaningful national laws for Space mining companies incorporated there. And would this then make the activities of that company subsequent practice for the purposes of treaty interpretation, and state practice and evidence of opinio juris for the purposes of customary international law? The answer, unfortunately, could well be ‘yes’.

Then there is China, which has recently emerged as a major spacefaring state and is unlikely to support or accept new rules that have been crafted to suit US interests. China has ratified the Outer Space Treaty, is an active participant at COPUOS, and co-operates with the United States and other Western countries in Space-based search and rescue (COSPAS-SARSAT)Footnote ¹²² and disaster relief (the Disasters Charter).Footnote ¹²³ But its considerable political and economic power, fast-growing Space capabilities and increasingly assertive approach to foreign relations all suggest that China will either go it alone on Space mining or – perhaps more likely – seek to create its own group of like-minded states. The latter approach would be consistent with China’s creation of the Belt and Road Initiative and the Asian Infrastructure Investment Bank, as well as its open invitation to host foreign astronauts on its new Tiangong Space station. A Chinese-led bloc of spacefaring states would likely develop its own practices and procedures, different from the US-led approach under the Artemis Accords, with even subtle differences – such as on safety zones – being potentially important.

One thing is certain. In the absence of a multilateral process for governing Space mining, the approach taken by the United States risks the development of different, inconsistent and perhaps even conflicting rules and practices. This could, in turn, destabilise the entire existing Space governance regime, to the long-term detriment of international peace and security. By marginalising input from developing and non-spacefaring states, it could also replicate, perpetuate and even exaggerate current economic and political inequities as humanity moves into Space.

5.5.7 Safety Zones and Long-Term Stewardship

‘Safety zones’ are used around oil platforms operating in exclusive economic zones (EEZs) to prevent accidents involving ships. Under Article 60 of the 1982 United Nations Convention on the Law of the Sea (UNCLOS), a coastal state ‘may, where necessary, establish reasonable safety zones’ around oil platforms and similar installations.Footnote ¹²⁴ These safety zones may not extend more than 500 metres from the structure, and other states must be provided with ‘due notice’ of their extent. It remains unsettled whether a coastal state may create a safety zone around an oil platform on the extended continental shelf (i.e. beyond the 200-nautical-mile EEZ) or around a ship in motion, such as a ship conducting a seismic survey in support of oil and gas exploration.Footnote ¹²⁵

In the Artemis Accords, signatories express their intent to use ‘safety zones’ around Space mining operations to provide notification of their activities and to co-ordinate with other actors to avoid ‘harmful interference’.Footnote ¹²⁶ Arguably, this notification is necessary to allow full implementation of the consultation, due regard, and notification obligations in Articles IX and XI of the OST.Footnote ¹²⁷ The signatories say they will ‘respect the principle of free access to all areas of celestial bodies and all other provisions of the Outer Space Treaty in their use of safety zones’, which ‘will ultimately be temporary, ending when the relevant operation ceases’.Footnote ¹²⁸

These assurances are appropriate, but they are expressed within a non-binding instrument that was negotiated among a small group of like-minded states. This leaves the door open to selective application, abuse or at least contestation regarding any safety zone that is established. There is also a question of how China and other non-Artemis Accord spacefaring states might regard the rights of others in any safety zones that they themselves might choose to establish – now that the United States has opened this door. On the oceans, the behaviour of coastal states concerning safety zones has given rise to several disputes, most notably between the Netherlands and Russia, when a Greenpeace ship and its crew were detained for months after protesting offshore oil drilling in the Russian EEZ.Footnote ¹²⁹ Moreover, it is not clear that safety zones, as envisaged, are any better than the general duty to consult. Consultation could provide the desired notification of planned activities on the Moon and other celestial bodies without creating any boundaries, even if those boundaries are only non-binding and temporary.

The US effort to persuade other states to sign the Artemis Accords has undoubtedly been facilitated by the following provision: ‘The Signatories intend to use their experience under the Accords to contribute to multilateral efforts to further develop international practices, criteria, and rules applicable to the definition and determination of safety zones and harmful interference.’Footnote ¹³⁰ However, the United States might not be disappointed if the envisaged multilateral law-making efforts are postponed, fail or never take place. As we explained above, the United States and US companies are uniquely positioned to influence the development of customary international law concerning the conduct of Space mining, including through actual mining and safety zones. It is also possible that this influence might be bolstered by the Artemis Accords’ provisions on safety zones, not as treaty provisions, but as a weak form of state practice on the part of the signatories.

Of course, US-led efforts to ‘develop international practices, criteria, and rules’ for safety zones could also fail at the level of customary international law. Everything depends on the responses of other states, including non-spacefaring and developing states. Again, no single state or small group of states can make or change international law on its own, no matter how powerful and technologically capable they may be.

None of what is happening here is unusual in international law-making, including the fact that a powerful state is seeking to establish the framework within which state practice and any eventual multilateral negotiations will take place. Powerful states generally try to shape international law in their interests, rather than brazenly violating or simply ignoring the rules.Footnote ¹³¹ The postponement of negotiations until rules and practices can be shaped by a small group of like-minded states is one of the tried-and-tested strategies of hegemonic law-making. For this reason, less powerful states, including non-spacefaring and developing states, may wish to weigh in on this matter sooner rather than later.

There are long-term, global interests at stake. As prefigured in the Artemis Accords, safety zones could – depending on how they are applied in practice – provide a Space actor with some of the benefits of territory, while relieving it of long-term obligations of stewardship. It is easy to find analogies on Earth that support these concerns, including ‘orphan’ oil wells and abandoned mining tailings.Footnote ¹³² Moreover, since resource exploration and extraction could take considerable time in Space, a safety zone might remain in place for decades or even centuries, blurring any distinction between temporary use and de facto occupation.

We agree that safety zones could reduce the risk of certain kinds of accident by ensuring that Space actors do not encroach on each other’s operations. Geographic separation could be particularly important in low-gravity situations were dust and debris are easily dispersed. Our concern about the US-led push for an acceptance of safety zones does not deny their potential benefits, or that something like safety zones will be needed in some circumstances. Rather, our concern is that the development of safety zones, and standards for them, could be skewed in favour of powerful spacefaring states and companies from those states, enabling arbitrary boundaries, limits on access or other forms of unnecessary self-privileging. For this reason, safety zones, and Space mining operations in general, should be governed by rules informed by longer-term interests and diverse perspectives—including those of states in the Global South.

Current debates on international law and Space mining can benefit from the experience gained during the development of globally applicable rules on deep seabed mining. During the negotiation of UNCLOS, the United States demanded that private companies have access to deep seabed resources beyond the continental shelf. Most other states wished the deep seabed to be recognised as ‘the common heritage of [hu]mankind’,Footnote ¹³³ with mining subject to international regulation and oversight. The latter view prevailed, mostly due to co-ordinated negotiating by developing states.Footnote ¹³⁴ This is not the place to defend how that exercise in multilateralism is playing out; we simply point to it as an opportunity for learning.Footnote ¹³⁵ We also note that the United States’ failure to ratify UNCLOS has not posed a barrier to the treaty’s success: 168 other states have ratified the treaty and, since 1983, the United States has accepted that many of its provisions reflect customary international law.Footnote ¹³⁶

5.7.1 Clarifying Existing Obligations

The working group will want to take a broad approach to the issue of Space mining, one that encompasses all extraction of Space resources, whether conducted by governmental or non-governmental entities, and whether for scientific, mission-critical or profit-oriented purposes. Among the issues that it should address are necessary clarifications to existing rights and obligations, including:

1. 1 Freedoms in Space and the corresponding restrictions on them, as they pertain to resource extraction and use. These freedoms and restrictions are prefigured in Articles I and II of the Outer Space Treaty, but with Space mining now foreseeable, the time has come for the international community to elaborate on them.

2. 2 Limits on the involvement of military personnel and equipment in Space resource extraction and use. Article IV of the Outer Space Treaty specifies that the Moon and other celestial bodies ‘shall be used … exclusively for peaceful purposes’ and forbids ‘the establishment of military bases, installations and fortifications, the testing of any type of weapons and the conduct of military manoeuvres on celestial bodies.’Footnote ¹⁴⁹ However, Article IV does permit the use of military personnel ‘for scientific research or for any other peaceful purposes’, as well as the use of ‘any equipment or facility necessary for peaceful exploration of the moon and other celestial bodies’.Footnote ¹⁵⁰

3. 3 The obligation to ensure that ‘national activities’ carried out by ‘non-governmental entities’ are conducted in accordance with international law. Article VI of the Outer Space Treaty states, ‘The activities of non-governmental entities in outer space, including the moon and other celestial bodies, shall require authorization and continuing supervision by the appropriate State Party to the Treaty.’Footnote ¹⁵¹ With Space mining now foreseeable, detailed requirements for the authorisation and supervision of companies and other non-state actors are needed to prevent or mitigate the many risks identified above.

4. 4 The obligation of ‘due regard’. Under Article IX of the Outer Space Treaty, states are required to ‘conduct all their activities in outer space, including the moon and other celestial bodies, with due regard to the corresponding interests of all other States Parties to the Treaty’.Footnote ¹⁵² With Space mining now foreseeable, clarification is needed as to the level of care required. Is the obligation only to avoid reasonably foreseeable harm? Or does ‘due regard’ require the application of the ‘precautionary principle’?

5.7.2 Applying the Precautionary Principle

The precautionary principle was set out in Principle 15 of the 1992 Rio Declaration:

Today, the precautionary principle is central to numerous treaties, including most recently the 2018 Central Arctic Ocean Fisheries Agreement to which the United States, Russia, China and the European Union are all parties.Footnote ¹⁵⁴ This treaty prohibits all commercial fishing in the central Arctic Ocean until scientific research establishes that a sustainable fishery can take place.

The precautionary principle has also become part of customary international law, even if the precise content of the principle remains a subject of debate. As Patricia Birnie and Alan Boyle explained two decades ago:

Some of the main objections to the precautionary principle are that it is inherently unscientific because it requires action (for instance, regulatory action), or in some cases inaction (for instance, a moratorium on mining in a particular area), before certainty has been obtained, and thus it impedes progress. However, dealing with uncertainty is at the very heart of science, and making decisions based on identified and characterised uncertainty is not the same as making decisions based on conjecture. Nor does the principle require inaction except in grave circumstances; more often, it simply slows activities down so that uncertainties can be properly assessed.

Just as importantly, the precautionary principle (as set out in the Rio Declaration) calls for ‘cost-effective’ measures when science, with its uncertainty, identifies activities that are causing serious or irreversible damage. As humanity seeks to exploit other worlds for resources, let us be cognisant that we, as a species, might not know what we think we know, and acknowledge that there is far more about Space that we do not understand than that which we do. This is true even for the Moon.

Applying the precautionary principle to Space mining would make scientific assessments of risk necessary prior to any significant activity, including risks to materials of interest to science, risks associated with dust and debris, and risks to Earth and other celestial bodies. Sampling, for science or prospecting purposes, should be permitted, but always also used to inform risk assessment. The risks associated with dust and debris and asteroid trajectory alterations will require strict standards from the outset, at least until these risks become better understood and can be reassessed – not the other way around.

Applying the precautionary principle would also require an acceptance that Space mining operations cannot be allowed to proceed in the face of an unfavourable risk assessment. That said, an operator should be allowed to rework a proposal and have it re-evaluated through a second risk assessment. The goal is not to prevent Space mining, but to make it safer and more sustainable – and therefore a success in the long term.