# Cyber Resilience Limitations in Space Systems Design Process: Insights from Space Designers
## 2 Literature Review
They have highlighted the need for comprehensive frameworks and standards for assessing and ensuring the cybersecurity of space systems across the entire life cycle [61; 64]. Developing and enforcing harmonised cybersecurity practices across jurisdictions is essential for protecting the global space infrastructure [61]. The systems-of-systems nature of most critical space infrastructure consists of numerous components and communication links that can introduce vulnerabilities [65; 66]. Academics argue that to achieve resilience, a holistic approach that addresses the entire system life cycle and all domains of practice is required [65; 66]. Therefore, existing cybersecurity frameworks, primarily focused on a single organisation, may not adequately cover space assets' complete production value chain [58]. The challenge is the rapid evolution of cyber threats in the space domain. Adversaries are developing sophisticated attack capabilities to target space systems, such as anti-satellite weapons, jamming, and cyber-attacks. Space infrastructure must be engineered to withstand and adapt to these threats, but traditional risk management approaches may need to catch up with the dynamic threat landscape. The space \"weaponisation\" and \"militarisation\" is a primary concern for today's lawmakers [67]. Multiple scholars have raised their concerns that \"At this point, there are no agencies that restrict the use of satellites, and there is no overarching governing body that monitors the specific use of satellites. Even if one did exist, there are no mechanisms for enforcing any treaties/standards/governance.\" [41]. Therefore, from an international governance perspective, efforts to enhance space security have been ongoing. The UN has adopted several resolutions on the _\"prevention of an arms race in outer space\"_ and also presented a draft document headed _\"Treaty on the Prevention of the Placement of Weapons in Outer Space, the Threat or Use of Force Against Outer Space Objects (PPWT)\"_. Interestingly, the PPWT was developed by Russia and China [68]. In general, the PPWT focuses on the following three obligations:  
* No weapons to be carried in orbit either on satellites or space stations;
* No threat against any other outer space assets;
* Not to encourage other states/organisations to engage in prohibited activities. The EU likewise published a draft voluntary Code of Conduct for Outer Space Activities in 2008, which covers the freedom of access to space, security and integrity of space objects [68]. In addition, the White House released a Space Policy Directive (SPD5) entitled _\"Cyber Security Principals for Space Systems\"_ that establishes a broad set of guidelines for space companies in developing their cyber protection approaches [69]. These guidelines include the following:  
* Protect critical space vehicle functions from unauthorised access;
* Implement physical security for command, control, and telemetry systems;
* Defend against communications jamming and spoofing;
* Secure ground systems using National Institute of Standards and Technology (NIST)-aligned cybersecurity best practices;
* Maintain cybersecurity hygiene and intrusion detection for system elements;
* Manage supply chain risks by tracking products and sourcing from trusted suppliers. Recently, the NATO Cooperative Cyber Defence Centre of Excellence (CCDCOE) has also been revising the Tallinn Manual and has invited experts worldwide to review legal and policy challenges related to cyber war [70]. Therefore, these international efforts underscore the importance of a unified approach to maintaining the security and stability of space infrastructure amidst global challenges.