A Proposal for Implementing Automation in Satellite Control Planning

Abstract

INPE (National Institute for Space Research)’s Satellite Tracking and Control Center (CRC) has been performing TT&C control of satellites since 1993. Currently at CRC, flight dynamics activities and satellite operations planning are performed in an integrated manner. Most payload operations are either performed in real-time, over the visibility range of data receiving ground stations, or else triggered by user requests which conditions are typically predicted by flight dynamics models. Health maintenance required by satellites under CRC control comprises mostly attitude, orbit, power and data handling subsystems telemetry monitoring. Most housekeeping telecommands are planned on a case-by-case basis, upon telemetry trend analysis. The remaining few are mainly onboard ephemeris data updating. Because of these synergies, at CRC the flight dynamics team is also responsible for generating ground and flight operations plans. Software tools currently at use by the CRC flight dynamics team have been proven reliable over decades of continuous running, but are not easy to use or maintain. As technology rapidly changes, new machines must be acquired and, most often, they are not fully compatible with older platforms. Porting program codes from one system to another is costly. Moreover, software operation tasks such as filtering out erroneous measurement data and precisely adjusting input parameters have become a fine art that only the most expert flight dynamics operators can handle. Training a new operator for this purpose alone would be extremely time-consuming. By taking advantage of INPE’s alternative role as an academic institute, CRC has directed some scholarly researches towards satellite control automation. Most resulting works concerned about intelligent planning of flight operations, by managing time and resources among satellite passes over ground stations. Their byproducts would not afford actual spacecraft control operations without major modifications. Due to their academic focusing, they would not reflect the complexity of real systems. In order to fill this gap, a validation tool for such intelligent operations planners is proposed. This project aims at building a software tool that would verify the outputs of academic operations planners by feeding them into a satellite simulator. The tasks contained in the operations plan would be executed on the satellite simulator, which effects would be reflected on its internal statuses. These internal statuses would be compared to design limits set by the satellite developers, in order to either accept or reject the operations plan. It is expected that the resulting validated plan would be workable with actual missions. The final decision on its usability would be decided by the flight dynamics team, upon comparison of results with those from the legacy system currently in use.