The aim of this masters thesis is to assess the relation between two organizations with competences towards the European space policy that happen to be in dispute over these competences - the European Union (EU) and the European Space Agency (ESA). The main research question asks whether the ESA hinders further supranationalization of the space matters within the EU framework and the research uses the lenses of the theory of the rational design which highlights the importance of the Member States as the decisive actors in this question who have to incline one way or the other. This thesis examines relevant documents issued by the EU and the ESA, as well as at the positions of the Member States of the European Space Agency with regard to this dispute, and concludes that the ESA indeed hinders further supranationalization of the space matters within the EU framework because it goes against the positions and interests of the Member States. The hindrance reaches the level that the only thing the Member States are willing to do is to adjust the financial procedures in respect to the programmes run by ESA and funded by the EU to ensure their efficient implementation complying with EU rules.