Implementation of a KA-band communication path for on-orbit servicing

On-orbit servicing and space debris removal are two potential future applications for novel spacecraft designs. Driven by the complexity of the tasks to be performed in these scenarios, mission operations and planning becomes more demanding, which in turn calls for a real-time tele-operation (RTTO) spacecraft control concept. Contrary to fully autonomous satellites, RTTO spacecraft are interactively controlled by a human operator, usually located on the ground. To create high situational awareness for the operator, the control system including a long-range communication link poses substantial requirements on the link performance. Since long-lasting uninterrupted communication links are desirable for RTTO, end-to-end communication architectures employing Ka-band and a geostationary relay satellite have been investigated at the Institute of Astronautics. To investigate and characterize the end-to-end communication link from the spacecraft sensor and actuators to the human operator, a complete communication path including a Ka-band satellite link is implemented utilizing "hardware in the loop" at the institute. This paper describes the intended and partially realized setup and the implemented measurement methods for the key link performance parameters: time delay, packet jitter, and data rate. Additionally, preliminary results for two test setups are presented.