Resource and material efficiency in the circular space economy

<h2>Summary</h2> Although the space economy continues to generate substantial economic value, the present linear production-consumption paradigm has proven increasingly incompatible with long-term sustainability objectives. In response, the integration of circular economy (CE) principles—centered on reducing inputs, reusing functional components, and enabling recycling—offers a viable pathway for alleviating both orbital and environmental burdens. Crucially, CE implementation in the space sector supports the advancement of durable material design, prolonged operational lifetimes, <i>in situ</i> diagnostics, and closed-loop end-of-life strategies. This perspective investigates CE practices across multiple levels, from material innovation and system-level redesign to critical evaluations of current policy instruments and emerging commercial ecosystems. It presents a multidisciplinary perspective that synthesizes insights from materials science, software, spacecraft hardware, business models, and regulatory governance with the aim of identifying key leverage points for embedding circularity within the space economy. Circularity is not an incremental improvement but rather a fundamental transition toward sustainability, requiring coordinated progress across technological and cross-sectoral strategies.