Valuable resources that are rare on Earth can be found in enormous quantities in space [1]. For over a century it has been speculated that humans would one day mine asteroids or the moon, but the science has lagged so far behind the aspiration that this has been traditionally considered the realm of science fiction. That has changed rapidly in the last decade. Technological advances have progressed to the point where there is serious consideration of the possibility that benefits of space mining—in terms of selling resources back on earth and/or using the resources to fuel launching pads for space exploration—may soon outweigh the costs. One of the leading benefits of space mining is the potential environmental payoff: unlike traditional mining, space mining is conducted far away from human habitats and delicate ecosystems, and therefore represents an advantage for those who are concerned about the environmental and heritage implications of resource extraction.

At the time of writing, both private companies and government-funded space agencies are exploring the possibility of extracting minerals from space. The Chinese Aerospace Science and Technology Corporation and the (now defunct) private company Planetary Resources both launched successful missions to test key technologies that might be used in space mining, while another company (Origin Space) will proceed with its space mining ambitions soon [2,3] Meanwhile, both the NASA Institute for Advanced Concepts and the European Space Agency (ESA) funded projects to explore mining options on the moon [4,5]. In 2020, former U.S. President Donald Trump signed an executive order to stimulate private investment in space mining from U.S. companies [6], while the government of Luxembourg invested 200 million EUR in research and development associated with space mining technology and is setting up a European space mining center [7].

While there is growing interest in space mining within government and industry, academic attention is nascent. Engineers and economists have debated its feasibility [8,9,10,11] and anthropologists have discussed its heritage implications [12]. Others have discussed the political and ethical implications associated with space mining [13,14] and the challenges associated with its sustainable development [15,16,17,18].

Perhaps the greatest amount of attention, however, has come from scholars in law and international relations, who have monitored the evolution of policies and laws that make space mining possible [19,20,21,22,23]. In recent years, there has been growing concern regarding the pace and scope of progress in developing a legal framework sufficient to give financiers confidence to invest in space mining [24,25]. There are currently several initiatives designed to develop an international legal framework—conducted, for example, by the U.N. Committee on the Peaceful Uses of Outer Space and The Hague International Space Resources Governance Working Group—but progress is slow, resulting in significant uncertainty concerning the legal conditions under which resources in space can be mined. In the face of this uncertainty, some have made the case that private companies are turning towards alternative ways of demonstrating legitimacy and satisfying the vague conditions proposed by existing treaties such as the Outer Space Treaty [18,25,26].

One such alternative form of legitimacy is the notion of a social license to operate [25]. A social license to operate is typically interpreted as reflecting the acceptance of a company’s (or industry’s) practices by the broader public. The phrase emerged in the 1990s when it became clear that social and ideological opposition to mining was on the rise, and that meeting government and legal regulations alone was not always sufficient to gain legitimacy. From the perspective of the mining sector, social license to operate has emerged as a risk-management strategy, designed to reduce the potential for conflict with local communities [27].

The lack of empirical attention to what people think regarding space mining is surprising, because mining has traditionally been a highly contested and emotional enterprise, one that triggers strong moral and environmental objections [28]. Qualitative research on people’s attitudes toward traditional on-earth mining has revealed a cluster of concerns: air pollution, encroachment onto residential areas, land degradation, health consequences, and noise pollution [29,30,31,32]. One of the key predictors of people’s sensitivity to these potential downsides is trust: the extent to which people believe legislators, regulators, and mining companies themselves have the broader interests of the community at heart [27,33].

Over and above trust, there are a number of other psychological variables implicated in people’s attitudes toward mining. Particularly relevant to this paper, there is evidence that people’s attitudes toward mining sometimes assume a deontological moral quality, informed more by values and worldviews than by value-free appraisals of costs and benefits [28]; see [34,35,36] for related discussions of the impact of morality on climate change beliefs. Three of these worldviews are examined in this paper: the new ecological paradigm (NEP), political conservatism, and moral foundations.

The NEP is a scale that focuses in part on beliefs regarding the fragility of the environment and the importance of minimizing human impacts on the environment [37]. This construct is a powerful predictor of climate change skepticism [38] and of perceptions of environmental risk more generally [39,40]. Although the NEP has not been used as a predictor of attitudes toward mining (to our knowledge), it is a short theoretical leap to presume that endorsement of the NEP would be associated with more negative attitudes toward terrestrial mining.

Political conservatism is an outlook that encompasses a range of social and economic issues, including attitudes toward the free market. Elements of political conservatism have a central place in Kahan’s theory of cultural cognition, which argues that people’s attitudes toward science and innovation are shaped by culturally defined beliefs regarding power relations and the rights of individuals relative to the collective [41]. For example, if people have a strong belief in the free market and an intuitive moral suspicion of big government (as many conservatives do), then attempts to protect the environment through government regulation of business will be ideologically aversive. Similarly, if people have an intuitive moral suspicion of big business and free enterprise (as many liberals do), then emerging technologies stemming from private industry may be viewed through a lens of mistrust and concern. These basic ideological intuitions provide the motivation for people to reject certain scientific messages [42,43]. Consistent with this, various indices of political conservatism have been shown to be powerful predictors of attitudes toward climate science [38,44] and perceptions of the risks and benefits of other emerging technologies [45]. In the current study we measure political ideology both in abstract (i.e., as a measure of how “liberal” or “conservative” people are) as well as in terms of the specific dimensions of individualism and hierarchialism defined by Kahan and colleagues. Again, specific tests examining the relationship between political conservatism and support for mining are rare, but liberal attitudes have long been associated with pro-environmental activism [46] and energy-efficient attitudes [47]. On this basis, it seems reasonable to assume that liberals will be more anti-mining than conservatives.

Finally, moral foundations theory [48,49] describes the bases upon which people make moral judgments. The original theory described five foundations of morality. Two of these—care (in which moral judgments are based on concerns regarding care and protection of others) and fairness (in which moral judgments are grounded largely in perceptions of fairness and justice)—are together referred to as “individualizing” foundations. The other three are referred to as “binding” foundations: loyalty (based on concerns regarding group membership and loyalty to ingroups); authority (based on obedience and duty); and purity (based on the desire to preserve purity and sacredness). Notably, endorsement of these foundations is shaped by political ideology: liberals tend to prioritize individualizing foundations over binding foundations, and conservatives tend to prioritize binding foundations more than liberals do [50,51]. Furthermore, there is evidence that people with pro-environmental attitudes focus on individualizing foundations: for example, the bulk of newspaper op-eds and public service announcements designed to promote proenvironmental attitudes focus on individualizing dimensions [52]. Relatedly, the individualizing dimensions are positively associated with climate-friendly choices, whereas the binding dimensions are negatively related to climate-friendly choices [53]. However, Hang and colleagues [54] found that people respond more to corporate social responsibility efforts that are guided by binding, rather than individualizing, foundations. Furthermore, Wolsko and colleagues demonstrated that climate change appeals that canvas both the individualizing and the binding dimensions are particularly successful at encouraging mitigation efforts among people across the ideological divide [55,56].

The research reviewed above suggests that certain ideological mindsets may predispose people to morally object to traditional (terrestrial) mining. However, it is an open question whether these same psychological orientations would also predispose people to object to space mining. Indeed, one of the key points made by advocates of space mining is that it is a paradigm-shifting approach to resource extraction, one that minimizes the usual problems associated with mining on earth in terms of pollution, environmental degradation, encroachment on human habitats, and so forth. This argument was encapsulated by Craig and colleagues [8], who wrote that harvesting off-earth resources has an “incalculable sustainable benefit in that they can be retrieved with absolutely no damage to earth” (p. 1039). The implications of this are somewhat utopian: a future in which humans are able to harvest a wealth of resources in a way that has no environmental cost. Furthermore, it promises a future where mining companies are not subject to the same ideological and moral concerns that people have regarding traditional mining, and therefore are unshackled from the threat of backlash.