With a growing number of objects in space, the pressure to be sustainable and more efficient with resources is increasing. Driven by technological advancements, the reuse of space hardware becomes feasible and viable as alternative to spacecraft end-of-life disposal. Reuse of space hardware promises benefits in areas like mitigating space debris risks, cost reductions, and environmental sustainability on Earth and in space. However, challenges related to the space environment, like micro gravity, unknown changes due to radiation, and the energy requirements to perform maneuvers in space must be addressed in order to enable spacecraft reusability. Nonetheless, reuse of space hardware is an important objective related to long-term space exploration with implications on the human expansion into space. This paper investigates the requirements for reusability of spacecraft and if circular economy strategies can support implementing reusability for spacecraft. Based on the finding of expert interviews, it argues for design as a key enabler. It introduces design for X, design for circularity, and design for reusability, and explores how reusability of space hardware implies the need to include the space environment in design decisions.

The transition from linear to circular material flows has become a priority across industries. However, Circular Economy (CE) transitions remain fragmented. Research and practice often emphasize isolated aspects such as business models or production processes, without considering systemic interactions that shape and determine long-term sustainability and profitability. This paper conducts a strategic scoping review to advance a system-level perspective on CE implementations. It proposes a novel Circular System (CS) framework that integrates circular production, manufacturing, and business-model literature into a multi-level conceptual framework for understanding system-level dependencies relevant to engineering implementations, especially related to CE. Drawing on socio-technical transition theory and engineering design the findings show how these domains overlap, reinforce, or conflict across the micro, meso, and macro levels. The CS framework clarifies the linkages between technological innovations, organizational change, financing, and policy that enable or hinder circular transformation. The analytical utility of the CS framework is demonstrated through a satellite reuse case, which reveals systemic lock-ins that prevent circularity in a high-tech industry. Findings highlight that circularity is most effective operationalized through coordinated design choices, industrial capabilities, financial incentives, and policy conditions across all system levels. Applied to satellite reusability, the framework identifies where circular strategies break down and highlights leverage points that can support sustainability and competitiveness, moving the CE beyond isolated practices toward an actionable pathway for industrial and societal transformation.