We recognize the growing dependence on space systems for several applications, in addition to the emerging research focus of exploration accompanied by a diverse set of goals for human extra-terrestrial habitation. We are also cognizant that today, both environmental and malicious threats to space systems need to be tackled. These threats may originate in supply chains, in ‘grey’ zone warfare, or pseudo warfare from other nation-states. Such threats are increasing in the socio-political arena of a new space race and the speedy adoption of novel technologies with associated vulnerabilities. We have been considering the application of Software-Defined Networking (SDN) architectures in space systems as an example of new technologies in need of both security and resilience. Software-Defined Networking (SDN) transforms traditional networking architectures by separating the control plane from the data plane. This separation enhances scalability and centralized management of networks. Space systems as key enablers of critical services can take advantage of the benefits offered by SDN. Our paper highlights some cyber threats and vulnerabilities in SDN-based space systems. Furthermore, we analyse the cyber threats using the Space Attack Research & Tactic Analysis (SPARTA) framework. Space Attack Research & Tactic Analysis (SPARTA) provides a comprehensive analysis of potential threats to space-based systems.