# Cyber Resilience Limitations in Space Systems Design Process: Insights from Space Designers
## 6 Conclusions  
This study demonstrates that experts in the space domain exhibit a nuanced understanding of cyber resilience and face particular challenges in their engineering projects. Through interviews with professionals from diverse roles, we identified several key themes that inform the current state of cyber resilience in space design. First, our findings indicate that a substantial preference among experts incorporating cybersecurity and resilience considerations throughout the engineering design process emerged as a critical theme. Almost all participants emphasised the importance of embedding security measures from the earliest stages of system design, advocating for principles such as zero-trust architecture and security by design. These approaches ensure that security is integral to the system life cycle, enhancing overall resilience and reducing vulnerabilities. Second, there is also a preference for Model-Based Systems Engineering (MBSE) and Agile methodologies. These approaches are viewed as synergistic, providing a robust framework for developing complex systems with enhanced flexibility and adaptability. A noteworthy point of discussion was the tension between principles-based standards and compliance-based approaches. While principles-based standards offer flexibility and focus on desired outcomes, they can lead to inconsistent implementation if not properly guided. Contrarily, compliance-based approaches were identified to provide clear, prescriptive measures but may need help to adapt to growing threats. The participants underscored the need for a balanced approach that leverages the strengths of both methods to maintain robust cybersecurity. The study furthermore highlighted the participants' understanding of challenges posed by insider threats and the complexities of testing and validating cyber resilience in space systems. The complexity of space systems, with their numerous interdependent components, demands continuous and rigorous testing to ensure resilience against cyber-attacks. Similarly, the participants pointed out the need for improved stakeholder understanding, effective communication and alignment regarding the importance of cyber-security measures. Additionally, budget constraints were identified as a significant barrier to investing in the latest technologies and staff training necessary for robust cybersecurity. In conclusion, our findings underscore the critical importance of integrating diverse engineering methodologies and proactive cybersecurity measures to enhance the resilience of space systems. The insights provided by the experts highlight the necessity for a comprehensive and integrated engineering approach that addresses the unique challenges inherent in space design due to their size, location, and complicated technology. Moving forward, we advocate for further research in developing a novel cyber resilience framework that leverages proven methodologies and incorporates security by design principles. In future work, we intend to develop the proposed framework and employ the face validity method [106; 107; 108], a crucial practice within research methodology, particularly in the context of validating frameworks and methodologies. Conceptualisation, S.S. and K.J. ; Methodology, S.S. and K.J. ; Software, S.S.; Investigation, S.S.; Formal analysis, S.S. and J.P.; Writing--original draft preparation, S.S.; Writing--review and editing, S.S., L.Q., F.D., J.P. and K.J. ; Visualisation, S.S.; Supervision, K.J., L.Q. and F.D. All authors have read and agreed to the published version of the manuscript. This research received no external funding. The data supporting this study are confidential and protected by agreements with space designers and UNSW ethics guidelines. Therefore, it is not publicly available in raw form. However, to ensure transparency and collaboration, researchers can contact the corresponding author to access derived or aggregated data. Permission will be granted following the legal process set by the UNSW ethics committee and the space designers.