## 4 Experimental Results and Discussion
### Discussion and Future Work  
This study evaluated mitigation strategies for satellite network security using three metrics: the network centrality measure, vulnerability score, and attack impact metrics. The results show that the strategy using both patches, which combines the OS and protocol patches, was the most effective. It reduced the centralities of critical nodes, such as the \(RT\), \(GW_{1}\), and the \(IoT\), disrupting attack paths and minimizing the network's attack surface. The CFR strategy blocked specific paths but had limited impact on the overall security, highlighting the need for its combination with the strategy of applying both patches for comprehensive defense. Further exploration of the OS patch, protocol patch, and CFR is needed for optimal deployment in satellite environments. OS patching requires secure update mechanisms to reduce downtime and prevent attacks, while protocol patching provides robust protection but may require firmware modifications. CFR restricts high-risk commands but should be optimized to suit space-borne system limitations. Future research could focus on balancing security with operational efficiency to minimize performance impacts. Implementing these measures requires careful consideration of costs, power consumption, and system maintenance. OS patching demands secure update channels and monitoring, while protocol patching may incur additional certification and redesign costs. CFR's computational overhead may affect the system performance, requiring optimization for real-time processing in satellite systems. Compared with previous studies that have focused primarily on host-based vulnerabilities or isolated attack scenarios, such as jamming and satellite hijacking, this study provides a multisegment security evaluation by integrating host and protocol-layer assessments. Prior research has often lacked structured security metrics to quantify risk reductions after countermeasures, making it difficult to compare security strategies. Unlike conventional models, such as HARM and BAG, which focus on hierarchical attack representation and static risk estimation, TV-HARM incorporates multisegment dependencies and dynamic attack propagation. This approach allows for a more precise assessment of cascading threats across interconnected satellite, ground, and user segments. By leveraging TV-HARM and quantitative security metrics, this study enables a structured and comparative assessment of mitigation effectiveness, offering a systematic evaluation of real-world security threats in satellite networks. These findings highlight the need for structured secu \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**(a) Targeting the space segment** & & & & \\ \hline \hline \multirow{4}{*}{\(t_{\text{713}}\)} & No Patch & Almost Certain & Significant & Extreme \\  & OS Patch & Almost Certain & Moderate & High \\  & Protocol Patch & Almost Certain & Moderate & High \\  & Both Patches & Likely & Moderate & Medium \\  & CFR & Almost Certain & Moderate & High \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Security assessment using attack impact metrics. rity assessments that ensure that mitigation strategies are both effective and applicable in real-world scenarios. TV-HARM offers a promising approach for enhancing satellite network security, but its deployment in commercial and government infrastructures presents additional challenges. Its feasibility depends on adaptability to mission-critical systems with strict latency and resource constraints. Compliance with international satellite security regulations, such as those set by the International Telecommunication Union (ITU) and 3 GPP (Third-Generation Partnership Project)'s Non-Terrestrial Network (NTN) standards, is crucial for broader adoption and interoperability across global satellite systems. Unlike previous studies that have focused on qualitative risk assessments, TV-HARM provides a structured, quantitative method for evaluating security threats in satellite networks.