Advancing Coalition Typologies in the Advocacy Coalition Framework: Evidence from U.S. Space Policy

The U.S. space policy subsystem is undergoing significant transformation, driven by evolving priorities such as Moon-to-Mars endeavors, deep space exploration, and low Earth orbit activities. Historically, this subsystem has transitioned from a public technical domain to a public-private partnership, encompassing a diverse array of stakeholders from governmental and private sectors. This cross-national policy subsystem reflects broader trends, including commercialization, international collaboration, militarization, and economic development, which are reshaping coalition dynamics and stakeholder interactions. This study uses the U.S. space policy subsystem as a case study to refine and expand the typologies of subsystems and coalitions defined under the Advocacy Coalition Framework (ACF). Specifically, it examines how changes in the number and composition of policy actors, discourse networks, and the international space policy agenda influence coalition structures and policy outcomes. To achieve this, U.S. Congressional hearings, legislative bills, Presidential Executive Orders (EOs), international space agreements, and treaties from 1958 to 2023 are analyzed. First, witness affiliations in congressional hearings are assessed to track diversification beyond traditional government roles, reflecting shifts in societal, privatization, and international collaboration dynamics. Second, discourse network analysis (DNA) maps changes in actor congruence, coalition structures, modularity, and policy concepts within space policy discussions. Finally, topic modeling of international agreements, EOs, and treaties highlights the evolution of the U.S. international space policy agenda over time. Through this multi-method approach, the study provides new insights into coalition and subsystem typologies within the ACF, advancing understanding of how coalitions within a policy subsystem adapt to emerging policy agendas and the entrance of new policy actors.