The European Space Agency (ESA), as the regional space agency in charge of European space activities, is a unique International Governmental Organization (IGO). It does not have the usual tripartite structure of an IGO but instead has only two organs, one decision-making and one executive organ. The main policy and decision-making organ of ESA is its Council in which all the ESA Member States are represented. Even though the ESA Council meets on two different levels, the delegate and ministerial, it does not have two different organs. There are, however, a plethora of subordinated bodies that help the ESA Council reach its decisions. Moreover, as if becoming an ESA member is not already a complex process, it becomes more complicated in relation to substantial financial burdens. It would be logical that once a country is accepted as an ESA Member State, to participate in all the decisions that concern the agency. However, there are no differentiated levels of development or geographical regions. The only exception are the optional programs, which concern only the participating States. This simple organ structure, combined with a complex accession process, is what allows ESA to reach uniform up to date decisions, to perform checks and balances. ESA can readjust its policies (if necessary) during the ministerial Council every three to four years.

Furthermore, ESA’s normative pyramid is another specific feature of this organization. The ESA Convention, including the five annexes which form an integral part thereof, can be categorized as the main normative source and overarching structure for a wide variety of acts (including many, which contain legal obligations). The objective of the ESA Convention annexes is to elaborate on the provisions of the core text. Building upon this basis, a whole body of secondary derived legal norms has been developed, such as Regulations, Rules, Resolutions, Agreements etc. The Council approves mandatory activities, adopts Resolutions and Recommendations, accepts optional Programs in the form of Program Declarations, and it adopts other acts, that are all secondary derived norms. In a similar manner, the ESA Director General (DG), as the executive body and ESA’s legal representative, can issue administrative and other instructions required for the management of ESA, which are binding upon ESA’s staff. Alternatively, the ESA DG may delegate his authority in defined cases. Lastly, as an IGO cooperating with international partners, ESA can conclude various types of international agreements with different levels of complexity.