Technology Development For Real-Time Teleoperated Spacecraft Mission Operations

Upcoming space missions in the fields of on-orbit servicing and space debris removal will face highly complex tasks which require significant increases in complexity and capability of spacecraft systems, as well as increased dexterity of manipulators. In order to provide methods and technologies allowing real-time teleoperation in orbit, the Institute of Astronautics (LRT) at the Technical University Munich (TUM) is researching different technologies that will be needed for this new type of spacecraft mission operations. With the on-orbit servicing scenario as leading example mission, the main focus lies in developing technologies needed for teleoperated close-range proximity operations including inspection and docking maneuvers.During the past years several academic research projects have been centered around the setup of a hardware-in-the-loop (HIL) experimental setup called RACOON lab (Real-time Attitude Control and On-Orbit Navigation). RACOON allows a HIL simulation of the relative motion between two satellites. One of these satellites, representing the chasing servicer spacecraft, can be teleoperated from a mission control center via a real-world satellite link using the LRT's own Ka-Band ground station. The combination of the three major elements of a teleoperation system, namely teleoperator, space link, and human operator workspace, allows high-fidelity simulations accompanying subsystem technology development.Besides a description of the overall test setup, the paper will highlight some of the research that has been done to realize the envisioned real-time mission operations. This research covers the area of human-machine interfacing and operator situation awareness, as well as the area of the real-time communication link. For any human ground operator, situational awareness is substantial for effective, efficient, and safe teleoperation. One of our research projects evaluated the enhancement of operator situational awareness through an additional robotic camera arm which could be positioned freely around the chaser spacecraft, thus enabling additional vantage points during proximity operations. These studies were supported by complementary work that developed specialized prediction and attitude displays in form of head-up displays. Another key aspect for the real-time tele-operation is the communication link. In the FORROST research project the communication link including geostationary relay satellites is characterized through measurements of quality of service parameters (latency, jitter, bandwidth, error ratio). With these measurements the critical elements can be identified that lead to link degradation (e. g. high latency) which will make an interactive control impossible. This research is supported by software simulations evaluating different communication architectures with respect to their RTTO suitability.