Global governance arrangements are produced and sustained by an array of professionals who sometimes compete and sometimes collaborate over policy construction. Where trained scientists fit into this picture and how they influence policy formation is a question of great importance for stakeholders vested in the science-diplomacy nexus, given the role of technical knowledge in complex and uncertain diplomatic challenges. However, this Op-Ed argues that understanding the social dynamics that constitute science diplomacy in practice requires the use of concepts and theory from Science and Technology Studies and practice-theoretical work in global governance scholarship that can accommodate the contingency of professional life in this field of action. Using the arena of outer space governance to illustrate this point, I contend that using this scholarship can open up conceptual space to consider inter-professional contestation and intra-professional reimagination at the science-diplomacy interface. In turn, this approach can enhance understanding for science diplomacy practitioners as to what it means to be a scientist engaging at this nexus and what cycles of professional stasis and change are taking place.