Critical Space Infrastructure (CSI) is in the formative stages of development with high levels of complexity, uncertainty, and fragmented development viewpoints. As CSI continues to evolve, Complex System Governance (CSG) provides an insightful set of perspectives that can advance prospects for smoother CSI development. CSG offers a Systems Theory-based approach focused on improving complex system performance through purposeful design, execution, and evolution of critical system functions. These functions establish communications, control, coordination, and integration and ultimately determine system performance. CSG is particularly appropriate for CSI development to: (1) clarify and structure dialogs around critical systemic issues across the spectrum of techno-socio-political-economic frontiers, (2) provide a mapping of the governance for a complex CSI system and its context to identify fragmentation sources and systems-based challenges, (3) offer a paradigm, methods, and tools for the discovery of ‘deep systems issues’ and alternative resolution paths based on systems theoretic formulation, and (4) drive the system science-based engineering of applications to accelerate more coherent CSI development.