Grand challenges demand collaboration through innovation across diverse stakeholders to address complexity and uncertainty. This study explores multi-stakeholder dynamics in R&D consortia, focusing on the IRIS² project—a European satellite initiative emphasizing strategic autonomy. By examining the interplay of coopetition and client-supplier relationships, we uncover the challenges of managing conflicting interests, diverse priorities, and risk-sharing among public and private actors. Using a longitudinal qualitative case study approach, we reveal how governance structures and collaboration strategies evolved to address these challenges. Key findings highlight the necessity of redefining roles to mitigate tensions and enhance cooperation, particularly among competing firms. This research contributes to the inter-organizational relationship (IOR) literature by detailing the emergence and management of complexities in multi-stakeholder consortia. Practical insights suggest that early proactive strategies and adaptive governance are vital for fostering innovation in large-scale collaborative projects, especially in high-tech and strategically significant industries.
