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Towards Earth-Space Stewardship: Reflections on the ESS Conference 2026, Leiden, the Netherlands
Blake Harvey & Xiao-Shan Yap, 31/03/2026
Following the inaugural Earth-Space Symposium in 2024, the PlanetStewards Project co-organized the ‘2nd Conference on Earth-Space Sustainability: Law, Stewardship & Equity’ held in Leiden, the Netherlands, from 18-20 March 2026. As a continuation of the first global forum of its kind, the 2nd edition of the Earth-Space Sustainability (ESS) conference marked a significant step in deepening the intellectual foundations and global interdisciplinary collaborations driving the growth of the ESS network – the leading platform for advancing Earth-Space governance to address the most important and timely questions of sustainability, stewardship, and justice in the New Space era.
The conference was hosted at Leiden University and was co-organized by the PlanetStewards Project, the International Institute of Air and Space Law (IIASL), Leiden University, Secure World Foundation, and the EU COST Action FOGOS: Futures-Oriented Governance of Outer Space. The conference brought together 130 participants from 40 countries, reflecting the rapid expansion and diversification of the vibrant and international ESS community engaging with the complex challenges at the intersection of space activities, planetary systems, and sustainability governance. As co-organizer, the PlanetStewards Project played a central role not only in convening this growing community, but in shaping the conference’s broader framing, positioning Earth-Space governance as an integrated, interdisciplinary field that moves beyond siloed, fragmented, linear, and instrumental approaches to Earth-Space challenges.
As a critical forum inviting researchers and practitioners to engage with an emerging Earth-Space systems paradigm that demands a fundamental rethinking of sustainability governance, the conference enriched interdisciplinary exchange and future collaborations to address Earth-Space sustainability challenges in the 21st century and key questions of law, stewardship, and equity. Across the diversity of panels and discussions, a common theme emerged: that existing governance frameworks and knowledge structures are increasingly inadequate for addressing the scale and complexity of contemporary Earth-Space transformations. The conference served not only as a site of exchange, but as a space to critically engage with the epistemic, ethical, and cultural assumptions underpinning how space is governed. In doing so, it continued to advance an Earth-Space governance paradigm grounded in interconnection, reflexivity, and responsibility.
A hallmark of the conference was the set of dedicated special sessions led by the PlanetStewards Project, which engaged directly with foundational questions designed to push beyond existing debates, opening up new conceptual and practical pathways for governance and research. The first of these special sessions gathered experts from scientific, historical, and philosophical backgrounds to jointly explore diverse cosmological imaginaries and discuss the potential of treating ‘Starlight as Nature’. By examining how different traditions conceptualize the cosmos, the session highlighted how governance is always embedded within particular worldviews. Discussions centered on the idea of treating starlight as a form of nature, raising questions about environmental protection beyond Earth and challenging dominant assumptions about harm, value, and responsibility in space. The session emphasized the importance of incorporating more pluralistic and situated perspectives into governance discussions, prompting continued conversations throughout the conference on notions of intrinsic value of space and space objects.
The second special session led by the PlanetStewards Project brought together an interdisciplinary group of experts to jointly explore a potential stewardship plan for the Moon’s future, raising similar questions about incorporating non-instrumental values in discussions around stewardship. ‘A Stewardship Plan for the Moon’ engaged with the ethical and conceptual challenges of governing the Moon amid rapidly accelerating visions for lunar ‘territory’ arising from scientific, economic, and geopolitical competition on a global scale. The session explored how the speculative development of large-scale infrastructures including moon bases, lunar data centers, and nuclear power systems bring new social and environmental challenges, including the marginalization of intrinsic and cultural relationships for diverse communities around the world.
​Two thematic rounds engaged participants in first defining lunar integrity and secondly addressing practical considerations for whether there is room for a stewardship turn. The discussion highlighted that emerging lunar governance is being shaped largely through instrumental, scientific, and commercial logics, while deeper ethical, cultural, and non-instrumental values remain marginalized despite being central to how many understand the Moon and its integrity. It also underscored the need for a broader, more inclusive stewardship approach – one that addresses fragmented decision-making, integrates diverse voices, and rethinks human-Moon relations. The insights developed in the session were complemented by a keynote address by Marjolijn van Heemstra on the development of a Moon Embassy which engages us in asking what the Moon wants from humanity, adding poetic and non-instrumental relationality to key governance discussions and collaborations for lunar sustainability.
​The third special session led by the PlanetStewards Project focused on the potential development of an 'International Assessment Panel on Earth-Space Sustainability'. Building on the recognition that governance challenges are increasingly complex and interconnected, this session explored how a global assessment mechanism could help synthesize knowledge and inform decision-making. At present, most policy proposals or potential institutional arrangements addressing human activities in outer space only address isolated issues, overlooking broader interests and values. This session brought together leading experts to discuss the potential of an independent assessment body to report on the various sustainability issues in an integrative manner. The inter and trans-disciplinary panel discussed the shortcomings or ‘gaps’ in the current science-policy approaches, the role of an independent body, and to what extent it will be politically feasible. Discussions addressed issues of legitimacy, inclusivity, and representation, as well as the risks of reproducing existing asymmetries in global governance. The session highlighted the need for coordinated knowledge infrastructures that are both interdisciplinary and reflexive.
The congregation again focused on critical questions of justice and equity in a multi-planetary context, the key concern of the earth-space governance model. Speakers presented on current hegemonic trajectories of astrocolonialism, astrocapitalism, and the frontierization of space, asserting the importance of the pursuit of ‘earth-space sustainability’ as a means to achieve just planetary futures aligned with alternative ‘earth-centered imaginaries’ over the dominant, unrealistic visions of democratization via conquest born of 'human-centered imaginaries'[xii]. Further, discussions on North/South patterns in the access to and transfer of space technologies[xiii] and the applicability of environmental multilateralism for earth-space governance-centered[xiv] questions of global equity and the role various governance approaches may play in perpetuating longstanding systems of marginalization and inequality.
Across these sessions, PlanetStewards’ contributions underscored a central insight: that advancing Earth-Space sustainability requires not only new governance instruments, but a rethinking of the underlying assumptions, values, and narratives that shape how space is understood and governed. This perspective was carried throughout the broader conference programme, where PlanetStewards researchers played a visible role in shaping discussions across panels and presentations. Principal Investigator Xiao-Shan Yap opened the conference and moderated the project's special sessions, while Frank Biermann contributed to the opening panel on Earth-Space sustainability as a planetary challenge, drawing on critical insights from earth system governance.​
​​Building on this, Timothy Pape examined governance dynamics through his work on the International Space Station decommissioning plan, while Martin Sanzana Calvet explored the opportunities and limitations of applying Rights of Nature to dark and quiet skies. Erin Jones and Blake Harvey each addressed the governance of satellite megaconstellations from different angles, with Jones focusing on the entanglement of Starlink, conflict, and global governance, and Harvey analyzing how the international dark sky community seeks to influence orbital governance. Ritu Dhingra, in turn, brought in alternative cosmological perspectives through her work on ancient Indian foundations for Earth-Space stewardship. Together, these contributions reflected the breadth of PlanetStewards’ engagement, spanning legal, ethical, environmental, and socio-political dimensions of Earth-Space governance.
More broadly, discussions across the conference ranged from legal and regulatory developments to operational challenges, environmental impacts, and questions of equity and access, while converging around the need to move beyond fragmented approaches toward more integrated forms of governance. This was reflected in the conference's five thematic tracks, which addressed cosmological imaginaries and futures, environmental integrity, commons and resource governance, anticipatory risk governance, and questions of peace and stability. Across these areas, participants highlighted the limitations of existing institutional arrangements and particularly their difficulty in keeping pace with rapidly expanding space activities and the growing diversity of actors involved. Attention repeatedly turned to the gap between formal rules and practices on the ground, as well as to the need for more anticipatory and inclusive governance approaches. Ensuring broader participation beyond traditional institutional actors emerged as a key priority, reinforcing the importance of sustained, interdisciplinary engagement as governance efforts continue to evolve. As a continuation of the first Earth-Space Symposium, the conference further established the importance of sustained, interdisciplinary engagement on these topics.
The conference represents a hallmark moment for the project, both in terms of consolidating its contributions and in setting the stage for future work. The ideas and collaborations that emerged in Leiden will continue to inform ongoing research and engagement, particularly in relation to the themes explored in the PlanetStewards-led special sessions. Looking ahead, the challenge will be to build on this momentum - translating these discussions into concrete frameworks, practices, and institutions capable of supporting more just, sustainable, and reflexive approaches to Earth-Space governance. As the ESS network continues to grow, we seek opportunities for exchange, collaborations, and partnerships including for the 3rd conference to come.
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Photos:
Jeroen Koopman, PlanetStewards Project