On one hand, the onset of perestroika and the associated policy of openness of the USSR to international cooperation in space opened new opportunities and unexpected advantages for ESA. On the other hand, there were certain doubts and drawbacks regarding collaboration with a new partner long considered “toxic” for both political and security reasons. As an intergovernmental organisation, ESA united several countries, each with differing perspectives on the potential for cooperation with the USSR. The development of a unified policy was considered a complex challenge for the entire management system responsible for decision-making. Clearly, the classified nature of Soviet space science activities, given their close ties to the VPK, did not make ESA leadership’s task any easier. However, these “shortcomings” of Soviet space were largely offset by its numerous advantages, which were recognised by the national space agencies. In the emerging triangle of ESA, national agencies, and the USSR, each had to determine its position based on its interests and capabilities. This chapter will examine the challenges ESA faced in its efforts to establish closer relations with the USSR.