Analysis of security threats and systematic defense strategies for satellite Internet

In response to the explosive growth of the global satellite internet and the five key evolutionary trends of LEO mega-constellations-scalability, networking, intelligence, servitization, and ecosystem expansion-this paper conducts an in-depth analysis of the asymmetric threats facing “100000-satellite" scale networks. Specifically, it examines challenges such as supply chain attacks, side-channel exploitation, and cross-domain coordinated strikes that target core aerospace nodes, cross-domain links, and space-ground integrated boundaries. To overcome the limitations of traditional defense models regarding heterogeneous interoperability, collaborative command, and system trustworthiness, this paper proposes a systematic defense strategy. This architecture establishes the “Satellite Internet Security Brain" as the decision-making core and the “Star-Cloud-Station-Terminal" four-tier agents as execution units, integrated with the NodeMatrix, DataMatrix, AppMatrix, and CodeMatrix governance frameworks. This approach effectively resolves critical challenges involving unified resource abstraction in heterogeneous environments, multi-source data interoperability, agile tactical response, and trusted full-lifecycle software evolution, thereby providing a robust solution for the long-term reliability of complex mega-constellation systems.