Architecture design of ground telecommand encryption function for spacecraft

The status of equipment which comprises a satellite should be controlled and monitored to operate the satellite and accomplish its mission. A satellite which performs the missions such as imaging of the specific target areas should continue to send the satellite command to shoot for targets. A communication satellite has to be commanded to configure a communications payload. Therefore normal satellite operation will be achieved through mutual communication between the satellite and its satellite ground control system. However, if any person with malicious intent sends commands which the operator does not recognize, or even by accident, any person without permission transmits commands, it can be a fatal problem and in worst case, could cause loss of the satellite [1][2][3]. Thus, the encryption system for telecommand has to be adopted to prevent a situation that the satellite has an impact due to abnormal commands [1]. This paper describes the ground TeleCommand Encryption Function (hereafter TCEF) implemented for the security of a satellite and the ROS developed for the operation of it, and presents the architectural design of the encryption key management and the encryption function. We also explain how they interface with each other.