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date: 13 April 2021

Ethics of Planetary Science and Explorationfree

  • Jacques ArnouldJacques ArnouldThe National Centre for Space Studies (CNES), France


Since the launch of Sputnik on October 4, 1957, the development of space activities has provided a kind of evidence for the conduct of human affairs, to the point of neglecting to question these activities from an ethical point of view: only since the beginning of the 2000s has a real ethical interrogation within the space community (French Space Agency, International Space University, COPUOS) been developed, in parallel with international law. Taking advantage of a rich cultural background and a cooperative sustained effort, space ethics contributes, for example, to better management of debris orbiting the Earth, evaluation of the social impacts of observation satellite systems, and the arrival of new private entrepreneurs apparently less aware of the impacts of managing space as a common heritage of humanity. If space law provides a possible framework and a set of principles for the current and future management of space activities, ethical principles must be considered to accurately assess their reasons for being and their consequences. The following questions are pertinent today: Has space become a trash can? Is space “Big Brother’s” ally? Is space for sale? Should space be explored at any cost? These issues require special expertise of the situation (e.g., the distribution of debris around the Earth, the capabilities of observation satellites); consideration of the global, dual (civil, military) nature of space; and reference to ethical principles (responsibility, vigilance). Human space flight, space tourism, and the search for extraterrestrial life are also subject to ethical questioning. At the beginning of the 21st century, space ethics remained a goal for the space community.

Introduction: Space, Humanity’s Last Frontier

“Space: 1. Common shortened form of outer space. 2. Field of human activities pertaining to outer space.” This definition is proposed by the Conseil International Pour la Langue Française (International Council for the French Language) in its Dictionnaire de Spatiologie (Dictionary of Aeronautics and Space Technology). Therefore, space is no longer just a place that starts 100 km above the Earth’s surface, as once proposed by Theodore von Karman; it is also what humans do there and do with it.

This technical dimension of space began with the launch of the first Soviet Sputnik on October 4, 1957; since then, it has continued with programs of exploration and utilization of space, thanks to the commitment of an increasing number of national powers and, more recently, private actors. The physical characteristics and dimensions of space often seem to exceed the capacity of apprehension and understanding of the senses and intelligence of humans. The technological steps to be taken and the challenges to be met remain numerous. Yet these properties of space make it a horizon, rather than a frontier, for the spirit of curiosity, conquest, and enterprise that is proper to humans, and will continue to do so for a long time.

Is the space community of engineers and politicians, national agencies and private companies, concerned by ethics? Ethics have been trendy for over 30 years. This subject, familiar to ancient philosophers and a fundamental building block of philosophical works and religious teachings, remains to this day frequently bound to the context of academic seminaries or to the institutionalized framework of ethical committees. Nowadays, however, it also exists outside these established fields, for it is claimed by experts and circles previously unfamiliar with it. Hence, ethics exist in management, journalism, commerce, finance, and even fashion. In fact, the term “ethical” is sometimes used as a social foil or a sales argument. On first deliberation, ethics seem to have become indispensable for the conduct of human affairs.

Among the many possible definitions of ethics is that the ethical approach is to question the obvious and to manage the possibilities. Presented as an invitation to question evidence, ethics is thus not reduced to a line-drawing exercise and even less to a pretext for prohibition. Ethics go much further, as they compel the people involved to focus on their essence, their motivations, their reasons for being, the conditions of their choices, and their ways of applying decisions. Managing the possibilities is about reducing the gap between the representation of the world constructed by space-related sciences and technologies, on the one hand, and the reality directly experienced by the average human, on the other.

Undoubtedly, those who work in space research or in space industry most often out of passion and personal choice, must practice and respect the ethical rules specific to their field of competence and responsibility. Jim Dator is convinced:

Why should ethics be of particular concern to space agencies and industries? Of course, ethical behavior should be of major concern to all of us in all occupations, but because of the special nature of space activities—their high costs, their danger, their public visibility, and their unique challenges and opportunities—space and ethical reflection must go together.

(Dator, 2012, p. 79)

Because space offers not only its actors but the whole of humanity a final frontier to cross, a singular horizon to try to reach, it is appropriate to consider a field of ethics that would be specific to space activities, in a similar way as has been and continues to be developed for medical research. It is even possible that the peculiarities of ethical questioning associated with space, because of its history, its cultural and social backgrounds, and finally the issues it deals with, can be a source of teaching for all fields of science and engineering.

Brief Genealogy of Space Ethics

The consequences of the emergence and development of a new technology are difficult to predict; space, born in the middle of the 20th century, is no exception to this rule. The development of astronautics has fulfilled the dreams and goals of those who achieved it first, the military and the scientists, those who have united their knowledge and intelligence, their wills and their means, to free machines and then humans from terrestrial attraction, make them orbit the Earth, and send them to discover the Moon and other planets. States have been able to assert or strengthen their sovereignty; entire domains of astronomy have been cleared. At the same time, the conquest of space has revolutionized the lives of humans in often unpredictable proportions, to the point that our societies have become very dependent on the incessant race of satellites over their heads (Arnould, 2011).

Apparently, this evolution—even this revolution—has been accomplished without our societies. Their leaders and their thinkers are questioning its merits, its consequences, and its prospects. In short, ethics do not seem to have presided for the birth and then the development of the space enterprise. But is that really the case?

In the Beginning, There Was Space Law

It is not uncommon for space to be considered “outlaw,” and as a result, it is a great surprise to discover that there is, on the contrary, a legal corpus, both national and international, that applies to space as a place as well as to actors of space endeavors. Today, this corpus is made up of five international treaties and agreements:

Outer Space Treaty—Treaty on Principles Governing the Activities of States in the Exploration and Use of Outer Space, including the Moon and Other Celestial Bodies of December 19, 1966, opened for signing on January 27, 1967, and entered into force on October 10, 1967. It was ratified by 98 states and signed by 27 more. Its principles were then completed and developed by other international texts;

Rescue Agreement—The Agreement on the Rescue of Astronauts, the Return of Astronauts and the Return of Objects Launched into Outer Space of April 22, 1968, entered into force on December 3, 1968, ratified by 90 states;

Space Liability Convention—The Convention on International Liability for Damage Caused by Space Objects of March 29, 1972, entered into force on September 1, 1972, ratified by 86 states;

Registration Convention—The Convention on Registration of Objects Launched into Outer Space of January 14, 1975, entered into force on September 15, 1976, ratified by 51 states; and

Moon Treaty—The Agreement Governing the Activities of States on the Moon and Other Celestial Bodies of December 18, 1979, entered into force on December 18, 1984, ratified by 13 states.

In addition, satellite owners and operators must abide by the regulations of the UN’s International Telecommunications Union, which is responsible for technically managing the allocation of the frequencies and orbits needed by satellites.

In recent years, national legislation is regulating space activities in a growing number of countries, including the United States, Sweden, Great Britain, Russia, France, Luxembourg, and others.)

The sources of such a legal body are numerous. In addition to case law (especially in the area of satellite activities), they are mainly based on legal principles (freedom of access, nonownership, international responsibility of states) and ethical principles (the use of cooperation and respect for the common interest). Because space activities have aroused the concern of lawyers since their emergence and led to the development of a law specific to them, it is necessary to acknowledge the existence of a form of ethical reflection that has been associated with them since the 1960s but that has remained “hidden” until the late 1990s.

Initiatives Without Tomorrow

Virtually no one remembers the book published in 1960 by Walter Pons titled Steht uns der Himmel offen? (Is the sky open to us?) (Pons, 1960). To this question, the German philosopher answers in a Socratic way: we will not really know the world, if we do not know ourselves first. To distance himself from the school of priests of Delphi, Socrates had indeed transformed the sentence “Know yourself, leave the world to the gods” into “Know yourself and you will know the universe and the gods.”

Two years after the publication of Pons’s book, on September 12, 1962, at Rice University Stadium in Houston, John F. Kennedy delivered one of his most famous speeches on the American space program, the one now titled “We choose to go to the Moon,” and he does not hesitate to underline the moral stakes that are thus launched to his country and to all (future) space powers: “Whether [space] will become a force for good or ill depends on man, and only if the United States occupies a position of pre-eminence can we help decide whether this new ocean will be a sea of peace or a new terrifying theater of war” (Kennedy, 1962).

In the same year, astronomer Bernard Lovell, whom the Queen of England had ennobled the previous year, published The Exploration of Outer Space (Lovell, 1962). After presenting the investigative techniques of astronomers of his time, the structure of the solar system and the universe, and the origin and evolution of the latter, Lovell devoted a final chapter to “some reflections on ethics and the cosmos.” In fact, he reflects on the conditions of extraterrestrial life, the consequences of a hypothetical discovery. Previously, he was concerned about Operation West Ford Needles, in which the U.S. military released several million copper needles at an altitude of 3,000 kilometers. The goal was to create a belt of space dipoles to serve as passive reflectors for military communications. But is it appropriate, Lowell wondered, to pollute space near the Earth? Lowell concluded his book on an optimistic note: the race to the Moon and, more generally, the space competition on which Americans and Soviets were then embarking provided excellent opportunities to deflect the budgets of the two great powers toward less belligerent activities.

Pons, Kennedy, and Lowell perceived that space technologies would continue to offer to humanity new means, and saw the need for questioning what place and purpose these new means should be given. But the early 1960s were not a time for a more widely shared awareness.

Twenty years later, in August 1982, the United Nations organized the second UNISPACE conference in Vienna, with a mandate of continuing international reflection on space policy and law; several delegations expressed their concerns and expectations. The delegate from the Netherlands wondered how to ensure that space would be put at the service of developing countries by allowing them to acquire greater technological independence; he was also concerned about the large share of space budgets still dedicated to military activities. Despite the commitments made by nations in the first space treaty drawn up in 1967, the militarization of space still appeared to be a worrying threat. Other delegates expressed similar worries, and the following year, UNESCO organized a teleconference during which the major spatial issues of that era were discussed from an ethical point of view: space debris and status of the data collected, weakness of international cooperation, and preponderance of military investment.

In March 1984, the Academy of the kingdom of Morocco organized a meeting in Casablanca called The Ethics of the Space Conquest. Participants showed great lucidity in worrying about the ever-increasing militarization of space (President Ronald Reagan launched his Strategic Defense Initiative, often referred as “Star Wars,” in March 1983), by stating the technical challenges related to various forms of pollution and legal records relating to data status. One of the participants in this meeting wondered whether the “damned of the Earth” would not be joined tomorrow by the “damned of space,” because of the difficulties, or even the impossibility, of Third World countries to access the data and, even more, the space technologies; these countries felt excluded and dispossessed in the face of the arrogance of the space powers, of their spirit of conquest (as mentioned in the title of the conference), resulting in inequality. Is it reasonable to think that space can enable real innovations in the social, cultural, and political spheres?

On January 28, 1986, the drama of the American space shuttle Challenger took place. Following the deaths of seven astronauts, NASA engineer Roger Boisjoly assumed the role of whistleblower. This accident serves as a case study for the issues of the ethics of the engineer (especially the effects of “group thinking”), and approaches were proposed to ensure that such would a disaster not occur again (Mayer, 2003). However, the Challenger accident did not suffice to create a commitment of the space community toward ethical questioning: no ethics committee was created. But in August 1986, President Reagan announced that the shuttle would no longer carry commercial satellite payloads (Rogers Commission, 1987). This tragedy raised questions in public opinion about the economic and especially the human cost of manned space flights that are the flagship of space exploration.

2001: Space Engages in Ethics

In July 2000, following an initiative by the European Space Agency (ESA) and its Director General Antonio Rodotá, UNESCO published a report prepared by Professor Alain Pompidou, entitled The Ethics of Space Policy. “The ethics of space policy,” says Pompidou, “must lead us to question the motivations behind human access to outer space and the exploration of the Universe, but also the degree of acceptability by public opinion, finally on equity” (Pompidou, 2000, p. 6). Despite its global perspective, this work deliberately ignores military activities, the main reason being that ESA only undertook civilian space programs. Following this report, UNESCO created a subcommittee on Outer Space within its World Commission on the Ethics of Scientific Knowledge and Technology (COMEST). It carried out several actions, most often with the support of ESA, for example, reports and conferences; and then, from 2005, it became increasingly inactive, before disappearing, probably because it was redundant and in competition with another UN body, the Committee on the Peaceful Uses of Outer Space (COPUOS). In June 2001, following the publication of COMEST report The Ethics of Space Policy, COPUOS devoted one of its annual sessions in Vienna to the theme of space ethics. It was a way of marking its territory, recalling that COPUOS, because of its legal competence, was the first organization to be concerned about the field of space ethics.

At the same time, the Centre National d’Études Spatiales (CNES), the French space agency, took a similar approach. At the beginning of 1999, Director General Gérard Brachet asked a group of engineers to launch the space ethics project. In October 2001, Arnould’s (2001) book was published, offering the fruits of this first reflection, La seconde chance d’Icare: Pour une éthique de l’espace (Icarus’s second chance: For a space ethic). The same year, CNES management created a position, ethics expert, with the mission of continuing the work begun by these CNES engineers.

Thus, thanks to these two initiatives, ethics are beginning to really emerge within the space community: organizations as COPUOS are devoting seminars to it; conferences organized by the International Astronautical Federation (IAF), the International Academy of Astronautics (IAA), and the Committee on Space Research (COSPAR) host papers on the theme of space and ethics; the International Space University (ISU), based in Strasbourg, France, honors its intercultural and interdisciplinary dimension by opening its summer schools and master’s degree to ethical questions; the European Science Foundation (ESF), the European Space Policy Institute (ESPI), which are studying the future of space activities are also integrating this new field; academics conduct research and produce publications on this topic (Milligan, 2016). However, no other space agency than CNES appoints a person or team to monitor the ethical dimension of their activities. Ethics is still a frontier for space to cross.

The Cultural and Social Situations of Space Ethics

Space has the distinctive feature of having a particularly rich cultural background that should not be overlooked when implementing an ethical question.

From Forbidden Cosmos to Aliens

Access to space has long been forbidden to humans, all the time and in all cultures: the sky was the domain of divinities, supernatural beings. Only after their death or a long spiritual path, a few human beings could get into heaven. This was particularly the case with Western culture, in which astronautics emerged: it was dominated by the cosmology inherited from Aristotle and taken up by Christian tradition. The world is divided in two: its sublunar region is occupied in the center by the Earth, a place of imperfection because it is perishable, ephemeral, and chaotic. The supralunar region that of the stars and divine beings is called cosmos because it is eternal, immutable, orderly, and therefore beautiful. In this representation of the world, humans, sublunar beings, cannot even imagine being able to join the cosmos with their bodies: travel to the cosmos is forbidden to them except, for the best of them, by the mind or after death. The idea that space travel was possible did not appear until the beginning of the 17th century, when the work by Copernicus, Galileo, and Kepler showed that the world is a “universe” made up of the same matter and subject to the same laws. The prospect of space travel can then feed the Western imagination: as early as 1638, Francis Godwin published The Man in the Moon, followed by Cyrano de Bergerac with Les États et Empires de la Lune (1657) and Les États et Empires du Soleil (1662). Edgar Allan Poe and Jules Verne followed suit before Herbert G. Wells and Arthur C. Clarke, who was himself a contemporary and early actor of the space enterprise.

Few modern techniques have a cultural background as ancient and rich as space. Aeronautics can be evoked here; but the sky of the aviators is not yet the cosmos, and the imagination of aviation is above all that of flight, not that of access to a reality as new and different as space. In fact, this cultural dimension of mythological space can be said to be one of the motivations, one of the reasons to undertake the exploration, the conquest.

On October 4, 1957, space was no longer just a matter of scientific, technical, or cultural imagination: with the launch of the first Sputnik, space became a reality. And soon, through its envoys, astronauts, and cosmonauts, humanity could claim to be a citizen of the cosmos.

The imagination does not leave the world of space; in his book Space and the American Imagination, Howard McCurdy (1997) shows how the authors and promoters of the U.S. space program have relied on cultural actors such as Walt Disney to generate interest and support from American public opinion and its imagination. Far from being an American exception, this link between dream and reality is found in other countries and cultures; thus, Japan’s interest in lunar missions is willingly explained by the place occupied in Japanese culture by Kaguya, the beautiful princess who fell from the Moon. And the name of China’s rover missions to the Moon is Chang’e, the Moon’s goddess.

At the same time, space continues to feed the imagination and ensure the vitality of science fiction literature and movies, a field of creativity that makes it easy to find ethical elements of reflection. Even imagined, the so-called close encounters of the third kind invite to question the respect to other, very different beings, regardless of the nature of the difference. Similarly, the societies that will populate the Earth or the planets in deep space for millennia to come are all reflections of humanity’s ideals or fears in relation to governance. And one must not forget the status of the new conquered worlds, of progress, or of the dangers to which the science and technology of the future will lead, whether predictable or simply imagined.

From the Cold War to Cooperation

Modern space travel was born through the will of governments and driven by two communities: the military and scientists.

The 1960s saw the race to the Moon as a “peaceful” race that, however, took place in the tense atmosphere of the Cold War: reaching the Moon first was not only a technological and human feat, but also a political victory! Initiatives for cooperation between space powers were rare, but France showed a remarkable ability to cooperate with the USSR as well as with the United States.

The 1970s saw a slight warming up with the joint Apollo–Soyuz mission, in July 1975, heralding the establishment of genuine cooperation between the two great space powers. However, it took nearly 20 years and profound political upheavals for two American and Russian spacecraft to dock again in Earth orbit. This time, real cooperation could begin: as bilateral exploration missions flourished, the idea of a space station in Earth orbit (a specialty until then mainly Soviet, then Russian) brought together Americans, Russians, Europeans, Canadians, and Japanese. Agreements and practice were sufficient to withstand political crises.

It is not, of course, a question of saying that, in space, everything is for the best in the best of worlds: competition has not disappeared with the fall of the Berlin Wall; political, scientific, and industrial constraints still hamper the advancement of knowledge and technology, competence and expertise. The arrival of the NewSpace movement of private initiatives, new actors, emerging nations, and private entrepreneurs is producing similar effects.

From Earth . . . to Earth!

Everyone knows the two images of Earth, Earthrise and Whole Earth, taken in December 1968 and December 1972 by the crews of Apollo 8 and Apollo 17, respectively, while en route to or from the Moon. These two views of our planet, whose blue and white shades contrast with the black background of the cosmos, are splendid and impressive; it is difficult to remain insensitive to the mixed impression of beauty, majesty, and fragility that emanates from them. Thanks to these two photos, the human species was finally able to see the Earth, its own planet, from a distance. Moreover, it managed to observe itself. Now, too, the Earth was made available to all “on supermarket shelves” (Debray, 1992, p. 412) as well as online.

Whether it is seen from the lunar surface, from an altitude of 400 kilometers, or scrutinized with a mosaic of satellite images, the Earth appears as a singularity within the cosmic universe. This experience leads, invites, and also forces us to review our usual landmarks, to put our references into perspective.

Compared to Earth observations by humans, those by artificial satellites offer the added possibility of an accelerated observation of land territories, as they can regularly repeat the passage over the same area and thus highlight the evolutionary, dynamic character of the Earth’s environment. These images show alternating day and night; alternating seasons; changing geographical, biological, and hydrological conditions; and more. However, this dynamic aspect is not as easy to accept as one might think. In the minds of many, nature is often still perceived as a kind of cosmos, in other words, as a reality fixed once and for all or, at the very least, limited to reduced and known variations. Any evolution, any movement of importance is experienced and understood as an attack on the majestic and (alleged) unalterable beauty of the world. What a surprise when it becomes necessary to recognize a global climate change, an increase in desert areas, a scarcity of natural resources . . . and to agree on the measures and actions that are necessary.

Four Ethical Questions for Space

Ethics are above all a matter of attitude, an interrogative practice. Why? How? With what consequences? It is not only useful but indispensable to ask these questions in order to grant our actions a truly human component, to integrate them into the societies of their time, and to undertake them with a deep concern for responsibility and sustainability. The previous pages were aimed at suggesting ways to broach such questions and providing responses thereto. Four questions are frequently asked.

Has Space Become a Trash Can?

On October 4, 1957, the Soviet Union launched Earth’s first artificial satellite, Sputnik, into orbit with a Semiorka rocket. Once the orbit was reached and Sputnik was released, while the first and second stages immediately fell to the ground, the third stage and the cap, now useless, remained on the same spatial trajectory as the satellite and became the first debris, the first pieces of junk in space. Together, they weigh more than 6,500 kg, whereas Sputnik weighs only 84: the payload represents just over 1% of the mass injected into orbit. After emitting its famous beep for 21 days, Sputnik remained in orbit for an additional period of useless existence, until it entered the atmosphere and burned after 92 days (Figure 1). It was discovered that it was impossible to go into space, to move around in it, and to work there, without producing debris, and this in a proportion that, according to Sputnik’s experience, appears disturbing, to say the least. The continuation of the space enterprise confirms these fears: today, only 6% of objects in Earth orbit are operational; the others are debris (Figure 2). And their numbers have continued to grow over the past 60 years.

Figure 1. Types of objects in Earth orbit.

Source: CNES.

Figure 2. Evolution of the number of objects in Earth orbit. Evolution of the number of objects in orbit (10 cm in low orbit and 1 meter in other orbits), between 1957 and 2019, tracked by the USSTRATCOM surveillance network.

Source: CNES.

Engineers and astronautical authorities are used to being criticized: “You turned space into a garbage can!” Public opinion is indeed moved to learn that thousands and even millions of small objects circulate above us, even if it is impossible to see them with the naked eye and they are far from obscuring the sky. The difficulty lies in the fact that there is (yet) no trash can in space and that these objects are like so many “bees whose hive would have been disturbed,” flying at very high speed (about 25,000 km/h at an altitude of 300 km) in random directions. More than aesthetic or moral concerns, the main issue related to space debris is the risk of collision with operational satellites, the International Space Station, or even an astronaut performing an extra-vehicular spacewalk.

This risk is real. On July 24, 1996, the French electronic surveillance microsatellite Cerise collided with a fragment of the third stage of an Ariane rocket launched 10 years earlier. The satellite’s gravity gradient mast (a pole about 5 meters long, intended to stabilize the satellite passively) was severed, and the satellite was rendered unusable. It was the American military, the only ones at that time with effective surveillance assets, who informed the French authorities. Was this the first collision in space? Probably not; some experts believe that the United States probably refrained from informing the rest of the world of less politically correct collisions between American, Soviet, and Chinese space objects. Subsequently, other events confirmed the existence of a real danger of collision between the machines that orbit the Earth. On February 10, 2009, a satellite of the Iridium constellation was struck by a Soviet Cosmos satellite, producing a thousand pieces of debris over 10 cm in size, which turned into potential new hazards in Earth orbits.

Thanks to their Cold War–inherited missile and spy-satellite detection systems, the United States has an effective means of monitoring space debris: radars for low orbits and telescopes for geostationary orbit. In total, nearly 150,000 observations are provided daily: they maintain a catalogue of about 9,500 objects, the size of which varies, to use American comparisons, from that of a baseball to that of a Greyhound bus. Europe does not have such a specific space surveillance system; however, space agencies and the military have developed and are developing radar and optical equipment. For example, the French Graves radar network (for Grand Réseau Adapté à la Veille Spatiale), developed to ensure the surveillance of low orbits, or the German Tira radar, installed near Bonn, are capable of tracking objects from 2 cm to 1,000 km altitude.

This monitoring is essential to allow for collision-avoidance maneuvers and prevent damage to the International Space Station or particularly useful and valuable satellites. Unfortunately, it is not possible to monitor debris measuring less than 10 cm. Although those less than 1 cm can be stopped by shield, those measuring between 1 and 10 cm are the most dangerous: no shield resists them, and they are difficult to spot; their number is estimated at 200,000.

Monitoring of space debris and avoidance maneuvers are not enough. If space agencies and operators want to maintain safe access to useful orbits, it is imperative to prevent any exponential increase in debris populations that could derive from any chain reaction. In other words, the previously terrestrial idea of sustainable development should be applied to space, and at a minimum, less debris should be produced.

Measures can be considered as soon as launchers and satellites are designed to minimize the amount of debris during launch and stationing operations. The objective is “one launch, one piece of debris,” in this case the launcher’s last stage, which necessarily remains on orbit. Apart from satellites or launching devices, no other object should be detached from this stage, which must itself be able to be drained in order to prevent any further explosion.

Another measure is to force the re-entry of the satellite at its end of life to bring it earlier into the atmosphere, where intense friction transforms it into a shooting star. Only the most resistant parts can ultimately fall back to land or, more often than not, to sea, as the oceans occupy 70% of the Earth’s surface. De-orbiting operations are complex and costly to carry out for most orbiting devices. For satellites too far from Earth, such as telecommunication satellites in geostationary orbit, the most effective way to prevent the proliferation of debris is re-orbiting them to a higher altitude.

The imperative to manage space debris and the difficulties associated with it make it obligatory to consult with actors and even impose constraints. As a producer of debris but also a victim (the Cerise case), CNES set up, as early as 1993, a Groupe de Synthèse sur les débris spatiaux (Space Debris Synthesis Group) to define its short-, medium-, and long-term policy on space debris and to inform all partners concerned with the subject, particularly the regulatory aspects. One of the important achievements of this group was the development and publication in 1998–1999 of a document entitled Introduction aux exigences de sécurité relatives aux débris spatiaux (Introduction to safety requirements pertaining to spatial debris). The preamble to this document stresses that good conduct should not be taken over by market and competition priorities:

Given the importance of the multiple consequences of its immediate application, consequences for CNES and its partners, it must be considered a recommendation whose application remains at the discretion of each program or project. The application of such a document will become mandatory once an international consensus has been reached . . . It should be referenced as a normative document in all contracts linking CNES to its partners. The requirements of this document will need to be followed at all levels of the organization of a program or project: partners, contractors, subcontractors, customers, suppliers, etc.

(Alby, F, 2007, p. 82)

At the European level, this document served as the basis for the drafting of a European standard, which was then transformed into a code of conduct, less restrictive than a legal standard. As a result, European agencies now have a common repository.

Finally, at the international level, the Inter Agency Space Debris Coordination Committee (IADC) is made up of 13 members: Agenzia Spaziale Italiana (ASI), Centre National d’Études Spatiales (CNES), China National Space Administration (CNSA), Canadian Space Agency (CSA), German Aerospace Center (DLR), European Space Agency (ESA), Indian Space Research Organisation (ISRO), Japan Aerospace Exploration Agency (JAXA), Korea Aerospace Research Institute (KARI), U.S. National Aeronautics and Space Administration (NASA), Russian Federal Space Agency (ROSCOSMOS), State Space Agency of Ukraine (SSAU), and UK Space Agency (UKSA). One of the main roles of the IADC is to identify future preventive measures that will limit the proliferation of debris. With this in mind, the IADC has prepared Mitigation Guidelines (1999 revised 2007) capturing the consensus among its members on the measures to be applied. The IADC has established itself as a force for proposals to the United Nations, the only structure that appears capable of promoting, through the work of COPUOS, international regulations that do not yet exist.

As regards space insurance, satellite manufacturers use it primarily to cover possible damage originating from satellites themselves, from launchers, or launch operations. No insurance claim has been reported on damage caused by debris (the Cerise satellite was not insured). Space debris is not the first of space insurers’ worries. However, they are aware of the current limitations of their coverage The current term of third-party liability insurance is in the order of 12 months; in other words, nothing is provided in the event of an accident due to debris or one suffered by an orbital structure after the first year in orbit. For this reason, and in absence of an effective insurance product, the creation of a fund to cover damage caused by debris has been proposed. Although space trash cans have not yet been invented, and capture techniques for large debris are yet only experimental, this topic is currently one of the most worrisome issues in the space community.

Is Space Big Brother’s Ally?

Complices or companions, sentries or guardians: Sputnik and the 5,000 satellites that have reached Earth’s orbits since October 4, 1957, deserve one or another of these names. Whether orbiting at a few hundred kilometers or at an altitude of 36,000 km, satellites, especially when working in constellations, are capable of providing exceptional “coverage” of the Earth and, each according to specificities, collect and transmit signals from the Earth, whether natural or artificial. The missions they can thus complete are multiple, and their list is never closed: observation and remote sensing, transmission and communication, positioning, navigation and timing, meteorology and climatology, intelligence and surveillance, and so on.

The level of accuracy, or “resolution,” of observation satellites, both civilian and military, has always aroused assumptions, assumptions, and fantasies. Over the past 50 years, it has evolved from 10s of meters for the first instruments on board to about 10 centimeters for satellites such as the U.S. KH-12. Is there a theoretical limit? Experts are happy to talk about 2–5 cm, as it is necessary to take into account disturbances of the atmosphere, impossible to correct at such level of resolution. The detection capabilities of these satellites nevertheless fuel the imagination, in particular, Thierry Rousselin explains, the constant confusion

between geostationary satellites (which allow to observe always the same zone twenty-four hours a day, but at low resolution due to their position at 36,000 kilometers above sea level) and scrolling satellites (which provide very fine details but never remain fixed above the observed point).

(Rousselin, 2007, p. 15)

Two systems, two types of capacity are, for the time being, technically disjointed:

As long as we do not know how to place instruments with very high spatial resolution on geostationary orbit (this could happen in 20 or 30 years because the research is progressing on the subject), the satellite that remains stationary and nevertheless records a detailed image of my house every quarter of an hour, or even continuously, is a fantasy.

(de Blomac & Rousselin, 2008)

But no matter the technical constraints, the idea and the image of the omniscient satellite continue to fuel the imagination of the promoters of ever more satellites and security, like that of their opponents.

The ability to observe the Earth and its resources, human populations, and activities belongs primarily to the space powers (currently a dozen), in other words, to the states that have the technological capabilities to build launchers and satellites, whether military or civilian. With the permission of these states, private companies have developed to “produce” images and market them (Spot Image, Ikonos, GeoEye, Orbimage, etc.) or simply to disseminate them (GoogleEarth, GoogleMap).

This dual evolution (increasing resolution capabilities and making images more available) causes as much enthusiasm as concern: In which world does one live if anyone (or almost anyone) can acquire images from any point on Earth (almost) and this (almost) in real time? Formally, in the face of the current capabilities of observation and surveillance of an instrument placed in orbit around the Earth, states and individuals have no right to the image or its equivalent in terms of privacy. On the contrary, there is a kind of customary law based on the practice of free access to space (the concept of “open sky”), introduced since the launch of Sputnik: the space powers of the time, the USSR and the United States, had to resolve to do so in order not to interfere with their own activities. The law then endorsed this modus vivendi by establishing the idea of total responsibility of states in space, as long as space activities take place on their territory or from their territory (the concept of launching state). However, how can one not question or even worry about techniques and practices that no longer reserve information and intelligence to military and government authorities alone, but also distribute them—even scatter them—among more numerous, more diverse users (including terrorist movements)?

This development is part of a broader movement of globalization that Marshall McLuhan described in the 1960s as a “global village” (McLuhan, 1962, p. 36). Since then, the phenomenon has accelerated and increased to the point of raising fears of excessive information and a saturation of our capacity to integrate it in order to decide and act. If globalization was born with the modern era, with the colonial and commercial expansion of the West, it has accelerated since the end of the 19th century. With the Second World War, this phenomenon took a new turn, that of complete globalization. Without denying its origins, and supported by an intensification of existing networks, globalization benefits from the emergence of gigantic industrial groups and the creation of a powerful and integrated capital market. “Integrated” is undoubtedly the key word of globalization to which space technologies, especially satellites, have provided undeniable support.

Yes, we call on all European governments, the Europe of the Twelve, to consider all solutions, including the use of force to stop the war. Tomorrow they will not be able to say that they did not know, they will not be able to say that they could not.

(Julliard, 1993, p. 138–139

With these words, Jacques Julliard concluded, on November 21, 1992, a silent demonstration against the policy of ethnic cleansing of President Milosevic’s regime. The journalist’s words describe the situation reached by our society: from now on, people can no longer say that they know nothing about the suffering endured by human beings, the atrocities carried out by others; they can no longer hide behind the curtain of ignorance, whether iron or paper, to excuse their silences and justify their immobility, their refusal to act and react.

Similarly, Jacques Ellul was not wrong to denounce the dangers that technological development poses to the freedom of the human being. In Le Système technicien, he wrote:

Technology has reached such an evolutionary point that it is changing and progresses without decisive intervention by man, by a kind of internal force that pushes him to growth, which leads him by necessity to an unceasing development.

(Ellul, 1977, p. 229)

The unprecedented development of new technologies, if it meets humanity’s demands and information requirements, is also accompanied by a paradoxical but proven process of indifference to events and isolation of people, condemned to become individuals, separated from each other, and immersed in the anonymity of multiple networks.

The idea of protection haunts human societies and gives arguments, even alibis, to their leaders to establish elaborate surveillance systems; satellites are participating. The establishment of power worthy of “Big Brother,” the central character of George Orwell’s 1984, has long worried some thinkers; Benjamin Franklin understood this when he said, “Those who would give up essential Liberty, to purchase a little temporary Safety, deserve neither Liberty nor Safety” (Franklin, 1755). It is not a question of opposing freedom to security, but of paying attention to the possible infringements of the former in the name of the latter, even though the reverse alone should prevail.

For, wide-eyed and with deployed ears in space, all these satellites built by humans can also be used to establish greater harmony in our world, without falling into the cross-check of excessive surveillance or security; the International Charter “Space and Major Disasters” is a remarkable example.

Created and drafted in Vienna in July 1999, this charter committed its signatories to provide free spatial data that they would possess to countries affected by major disasters, whether natural or human. The two founding space agencies, CNES and ESA, were joined by 15 organizations from various countries including India, China, the United Kingdom, the United States, Japan, South Korea, Brazil, and Germany, an amazing coalition that transcends the usual political and economic divides. Space agencies as well as national or international operators of space systems are likely to become members of the Charter; in addition, the civil protection, rescue, defense, or security agencies of the country of one of the signatories of the Charter become de facto authorized users. In order to provide assistance as soon as possible to the affected populations and the teams of rescue workers engaged in the affected areas, the members of the Charter ensure a permanent watch: after verifying the relevance and honesty of the request, the aim is to send images to people and services who need them, as quickly as possible, and to schedule specific shots. Because this initiative was launched independently of the usual political institutions, national or international, without being detached from them, and because it is part of a perspective of prevention, maintenance on alert, and at the same time rapid intervention in the very spirit of humanitarian aid, the Charter offers a singular and remarkable example of an effective alliance between knowledge and action, a true sense of circumstance and a will that is good, effective, and shared. Between February 2002 and March 2019, the Charter has been triggered 600 times, half of them because of flooding or submersion of coastal areas. So many triggers sometimes amaze the public, surprised by the effective ability of these space organizations to pool sensitive and expensive resources, as well as by the number of “major disasters” that hit human populations. No continent is spared, and many countries have sought the help of the Charter. Some examples include the first call, from the valleys of the Meuse and Moselle, France, on February 4, 2002; the second, on the same day, from the Democratic Republic of Congo; and the third, on April 9, from Afghanistan, where an earthquake occurred. The tsunami of December 26, 2004; the Fukushima disaster of March 11, 2011; and the earthquake in Nepal of April 25, 2015, gave rise to the activation of the Charter.

Space technology is not only being used as a matter of urgency at a time when government services and nongovernmental organizations (NGOs) are being mobilized to help people find satisfactory living conditions as soon as possible. It can also be used to prevent disasters, to trigger alerts, and to plan and organize land use that takes into account risk areas and potential threats.

Public or Private: Is Space for Sale?

From the 2000s, supported by strong personalities and by the U.S. administration, a movement for private space initiatives appeared in the United States. This movement resonated favorably among those who were nostalgic for the great exploration programs of the Moon and Mars, but also among the “giants” of the information society, in particular the GAFA companies (U.S. tech giants Google, Apple, Facebook, Amazon), attracted by this promising field where digital data are created and transmitted. This private entrepreneurial sector, born of a mixture of dreams of conquest, the opening of the American public market, and the phenomenon of digital transition, has been named NewSpace. These new players are shaking up the habits of space agencies and “historic” industrialists and forcing them to rethink their models and working methods. Europe was thus forced to start work on a new launcher, the Ariane 6 program, which is accompanied by other measures aimed at the new situation of satellites, environmental problems, and the evolution of the geopolitics of the space sector.

The reality of these changes should not lead to confusing NewSpace with the space of tomorrow. There is an increased and even necessary opportunity for agreements, partnerships, and collaborations between the public and private sectors; the public sector must ensure the development of new technologies and the sustainability of programs that are of public interest; the private sector is more involved in the creation and dissemination of uses close to the market.

These private initiatives are not without political and legal issues. In January 1967, the United States signed the Outer Space Treaty; Article 1 begins with the following words:

The exploration and use of outer space, including the Moon and other celestial bodies, shall be carried out for the benefit and in the interests of all countries, disrespectful of their degree of economic or scientific development, and shall be the province of all humanity. (Outer Space Treaty, 1967, art. 1)

On November 25, 2015, President Barack Obama signed the U.S. Commercial Space Launch Competitiveness Act that authorized U.S. citizens to appropriate space resources and, in particular, to exploit the metals contained in asteroids:

A U.S. citizen engaged in commercial recovery of an asteroid resource or a space resource shall be entitled to any asteroid resource or space resource obtained, including to possess, own, transport, use, and sell it according to applicable law, including U.S. international obligations.

(U.S. Commercial Space Launch Competitiveness Act, 2015, §51303)

Despite these latest precautions, it seems clear that, for American authorities, the interest of the “miners” of their country’s space comes before that of “all humanity.” President Donald Trump’s Executive Order of April 2020 confirms this idea:

Americans should have the right to engage in commercial exploration, recovery, and use of resources in outer space, consistent with applicable law. Outer space is a legally and physically unique domain of human activity, and the United States does not view it as a global commons. (Executive Order 13914, 2020, section 1)

Several legal experts are upset and want explanations requested by the United Nations Committee on the Peaceful Use of Space in the United States; they also organized a working group, all the more ardently because the Grand Duchy of Luxembourg followed the example of the United States with a similar legal decision.

For their part, the American entrepreneurs of the NewSpace welcome these government decisions. Among them is James Cameron, one of the founders of Planetary Resources, a NewSpace company that tested a first satellite in 2015 with a distant prospect of space mining. In his film Avatar, Cameron portrays the exploitation by the (bad) Earthlings of “unobtanium” on the planet inhabited by the (nice) Na’vi. This fiction is not only the futuristic and space adaptation of the conquest of the West; it also imagines the manufacture of human avatars . . . in line with the projects of transhumanism that plan to transform the human body or even increase population. What Cameron imagined in Avatar, he and other wealthy American entrepreneurs decided to achieve, both on Earth and in space, not necessarily by ignoring the laws, but by managing to interpret them or to change them in a direction that suits them: Are they all followers of the so-called libertarian thought? It expects institutions to respect and protect the freedom of all individuals to exercise their full right of property over themselves and the property rights they have legitimately acquired over external objects. Of course, there is no question of the common heritage of humanity.

Although it raises multiple questions, the NewSpace project and enterprise are also not without risks, not only economic for these entrepreneurs with broad visions, but also social and ethical. In its own way, Avatar staged them: the exploitation of nature’s resources, regardless of its protection or its proper distribution among the inhabitants of the Earth; the disinterest if not the rejection of a concern for social equality; the excesses of hybris, technological excesses, especially those related to the development of genetics and artificial intelligence. It is not a question of condemning a priori, but, at the very least, of worrying. Sometimes reality shouldn’t join fiction.

Should Space Be Explored at Any Cost?

If the early 20th century was marked by the end of the exploration of terrestrial continents, its cultures, and human societies, the development of science and technology opened up new horizons, especially those of the “infinitely small” and of the “infinitely great.” While scientists developed quantum theory and the theory of relativity, and the theory of the primitive atom and its development in the form of the so-called “Big Bang” theory, the birth of space travel made it possible to send interplanetary probes to the planets of the solar system and even beyond, to install space telescopes, and also to prepare manned flights, with the Moon as a first goal. On July 21, 1969, Neil Armstrong and Buzz Aldrin were the first humans to tread the lunar surface.

What happened next? First, an almost immediate disinterest in the missions that followed the success of Apollo 11, except for Apollo 13, the one that turned dramatic and narrowly avoided tragedy; then the cancellation of the last two missions originally planned. On December 14, 1972, when the strange lunar spider of the Apollo 17 mission left the Taurus-Littrow Valley, carrying the last astronauts who would walk on the Moon, it was as if a skylight closed in the night sky: since then, humans and their ships no longer leave the suburbs of Earth. However, the aftermath has not been disappointing. The space shuttle program, with its successes, dramas, and the stubbornness to prolong it, looks like an odyssey. The space station that today orbits above our heads is indeed international. Rhe images collected by the Hubble telescope fascinate the curious and even the jaded of the entire planet. Robotic missions to Mars, from Pathfinder to Curiosity, are followed by millions of Internet users. The adventures of the Japanese probe Hayabusa, launched to discover asteroid Itokawa, inspired three films in the land of the Rising Sun. The achievements of the Rosetta probe and its companion Philae, tasked with studying comet Churyumov Gerasimenko, in 2014 generated media interest far beyond predictions and expectations. These are all exploration missions that demonstrate the skill, enthusiasm, and tenacity of scientists and engineers alongside their fellow astronauts. Space does not disappoint; it still triggers repeated dreams among those who learn and discover the new chapters of its history, its odyssey. Yet what can one expect from revolutionary human space flights that seem confined to Earth’s orbits for a few years (if the U.S. objective of sending astronauts to the Moon by 2024 is fulfilled) or decades? What can one expect from a universe whose limits, observable with telescopes at the most piercing view, are lost in the mists of the unlimited, even the infinite? Should one repeat the observation of Pierre Auger, the first president of CNES?

There is no shortage of scientists who would prefer to achieve a kind of moratorium with science fiction, saying to its authors: “Stop, do not deflower what we’re going to do.” As it happens, the public is vaccinated. It is no longer surprised. Is this unfortunate?

(Arnould, 2006, p. 123)

In short, does space exploration really have a future, or should the 1960s be regarded as a spatial quirk? Can humanity really continue to dream of one day leaving its earthly cradle?

It should be noted that the technical progress that will transform robots into true astronaut collaborators in the near future has not succeeded in completely eliminating the debate born with human flights: the question of their opportunity. Is it reasonable to undertake ambitious human space flight programs, to devote large financial resources to them, to risk human lives? To this question, weighted answers can be provided, positive and negative. Opponents have made no shortage of arguments drawn from the past 60 years: the ruinous Soviet program to win the race to the Moon, the discontinuation of the Apollo program, the fatal accidents of the American Challenger and Columbia shuttles, the cost of building and maintaining the International Space Station, and so on. Proponents argue the human interest in exploration and knowledge, the impetus given to research and innovation.

While public institutions are struggling to provide successors to past or current missions, either for financial or technical reasons, private companies do not hesitate to announce their intention to take over from the agencies and to send humans to the Moon and even Mars. Will they have the technical means and the financial capacity? Will states allow them to do so if the risk of an accident exceeds the levels currently acceptable? Is it reasonable to want or simply to pretend to undertake an exploration of space at all costs? Today, the lack of a reflection on the meaning, the values, and the references of exploration is felt quite cruelly.

In an attempt to give them a broader perspective, it may be interesting to associate these questions directly related to human space flight to those raised by planetary protection. This expression requires understanding all the measures taken or to be taken in the context of missions to explore celestial bodies other than the Earth in order to reduce, control, or prevent any form of contamination: contamination of the territories explored when sending probes and human crews; and contamination of the Earth when samples and astronauts return. The scientific community, through COSPAR, takes these risks of contamination very seriously. The first and most obvious of the reasons is the scientific approach itself: the contamination of the area to be explored by terrestrial biological organisms would render the search for unknown extraterrestrial life virtually futile; the lack of precaution when a spaceship returns after having explored another planet could lead to contamination of samples by terrestrial organisms that would seriously hinder the continuation of their study . . . and could also endanger life on Earth, as science fiction writers have widely imagined. The latter threat is less a matter of the coherence of the scientific approach than of its responsibility toward humanity and the biosphere. This same responsibility also raises another ethical question, that of the possibility (of the right?) of humans to explore worlds other than their native Earth. This question has not escaped the astronomers either: some of them speak in favor of a sanctification of planet Mars in case traces of life, even fossilized, are found; others consider, on the contrary, that the phenomenon of life rests, among other pillars, on that of a powerful and inescapable propensity to spread, in any way. The case of astronauts is no less delicate: What steps should be taken in the event that, on returning from a mission on another planet, a crew member is found to be suffering from an unknown disease? Should we run the risk of bringing the crew back to Earth or plan for a permanent quarantine? What would be the fate of their companions? Should research and exploration be conducted at such a price?

The ethics of space activities are not limited to these four issues. Human space flight raises questions about financial cost, the risk management of astronauts, and the opportunity to develop space tourism. The search for extraterrestrial life requires reflection on planetary protection and the management of possible contamination of the planets explored or of the Earth; the question of colonizing a planet with life forms arises in the longer term. For these problems, ethical reflection does not bring judgment or a clear solution; but through space, political, scientific, or technical organizations, it now accompanies the development of programs, policies, and their implementation.

Conclusion: Ethics, Imagination, and the Future of Space

One of the promoters of ethics at CNES liked to repeat that this approach is an effective way of preparing for the future. Indeed, far from putting constraints and limits on human initiatives, ethical interrogation offers, on the contrary, the opportunity to entrench them in a more accurate awareness of their reasons and their causes, even the most deeply buried in a cultural terroir. At the same time, it allows one to recall and clarify the purpose sought, beyond the difficulties that have arisen momentarily.

This approach to ethics does not exclude its more regulatory and legal dimensions; these are even indispensable, as the current development of private space projects reminds one, to look to the future, to build the future, to become aware of the responsibilities of space actors.

As of June 2020, no ethics committee on space issues has been established at any level. The constraint of public opinion, the pressure of current events, and the near future remain weak or nonexistent; the multiplicity of areas would no doubt complicate its constitution and management. However, the interest of an ethical question remains: space does not lack projects, imagined by scientists, engineers, or even creators of science fiction. Through them, humanity says something about itself, its dreams, its hopes, and its fears; these projects therefore deserve to be studied in ethical terms, in order to support them or, on the contrary, to underline their limits and dangers.

Space is a recent field in science and technology and, more importantly, in the humanities and social sciences. However, its development has already profoundly influenced humanity, its understanding of itself, and its understanding and management of life in society. For all these reasons, actors who “make” and will make space agree to question the reasons, means, and consequences of space activities.

Further Readings

  • Arnould, J. (2011). Icarus’ second chance. The basis and perspectives of space ethics. New York, NY: Springer.
  • Arnould, J. (2017). Impossible horizon: The essence of space exploration. Adelaide, Australia: ATF Press.
  • Arnould, J. (2020). Ethics manual for the space odyssey. Adelaide, Australia: ATF Press.
  • Milligan, T. (2016). Nobody owns the moon: The ethics of space exploration. Jefferson, NC: McFarland.
  • Schwartz, J. S. J., & Milligan, T. (Eds.) (2016). The ethics of space exploration. New York, NY: Springer.


  • Alby, F., Arnould, J., & Debus, A. (2007). La pollution spatiale sous surveillance. Paris, France: Ellipses.
  • Arnould, J. (2001). La seconde chance d’Icare: Pour une éthique de l’espace. Paris, France: Cerf.
  • Arnould, J. (2006). La marche à l’étoile. Pourquoi sommes-nous fascinés par l’espace? Paris, France: Albin Michel.
  • Arnould, J. (2011). Une brève histoire de l’espace. Éditions Jean-Claude Béhar.
  • Dator, J. A. (2012). Social foundations of human space exploration. New York, NY: Springer- International Space University (ISU).
  • Debray, R. (1992). Vie et mort de l’image. Une histoire du regard en Occident. Paris, France: Gallimard.
  • de Blomac, F., & Rousselin, T. (2008). Sous surveillance ! Démêler le mythe de la réalité. Paris, France: Les Cahiers de l’Info.
  • Ellul, J. (1977). Le système technicien. Paris, France: Calmann-Lévy.
  • Franklin, B. (1755, November 11). Pennsylvania Assembly: Reply to the Governor. In Votes and proceedings of the House of Representatives, 1755–1756 (pp. 19–21). National Archives: Founders Online.
  • Inter-Agency Space debris Coordination Committee. (2007). IADC space debris mitigation guidelines.
  • Julliard, J. (1993). Nous ne pourrons pas dire que nous ne savions pas. Esprit.
  • Kennedy, J. F. (1962). Public papers of the presidents of the United States (Vol. 1). Washington, DC: Office of the Federal Register, National Archives and Records Service.
  • Lovell, B. (1962). The exploration of outer space. New York, NY: Harper & Row.
  • Mayer, P. (2003). Challenger, les ratages de la décision: La gestion manquée d’un risque majeur. Paris, France: Presses universitaires de France.
  • Luhan, M. (1962). The Gutenberg Galaxy. The making of typgraphic man. Toronto, Canada: University of Toronto Press.
  • McCurdy, H. E. (1997). Space and the American imagination. Washington, DC: Smithsonian Institution Press.
  • Milligan, T. (2016). Nobody owns the moon. The ethics of space exploration. Jefferson, NC: McFarland.
  • Pompidou, A. (2000). L’éthique de la politique spatiale. Paris, France: UNESCO.
  • Pons, W. (1960). Steht uns der Himmel offen? Entropie-Ektropie-Ethik: Ein Beitrag zur Philosophie des Weltraumzeitalters. Mainz, Germany: Krausskopf Verlag.
  • Rogers Commission. (1987). Implementation of the recommendations of the presidential commission on the space shuttle Challenger accident, recommendation VIII.
  • Rousselin, T. (2007). L’illusion de tout voir: les satellites dans les séries. In M. Winckler (Ed.), Le meilleur des séries, Paris, France: Hors collection Editions.
  • Trump, D. (2020, April 10). Encouraging international support for the recovery and use of space resources. Executive order 13914. Federal Register, 85(70).