This talk provides an extensive overview of security challenges in satellite systems. It covers vulnerabilities across space, ground, link, and user segments, using real-world examples in the past security research and the Viasat incident. By analyzing various attack methods from software vulnerabilities to radio frequency interference, this talk offers crucial insights for protecting current satellite infrastructures and anticipating future security challenges in the rapidly evolving field of satellite technology.In addition, the open community cubesat projects are growing.Vulnerabilities in these projects could also be a new threat.There will be 1 case study and new found vulnerabilities sharing for open project and a special case study of ground-station system in this talk.