Missionisable on-board flight safety based on real-time autonomous decision-making for microlauncher services
Creators: name:  N. MARTIN 
name:   C. NAVARRO 
name:   E. DIEZ 
name:   A. SABAN 
name:   J. MARTIN 
name:   M. ESCORSA 
Publisher: name: Proceedings of  the 9th European Conference for Aerospace Sciences. Lille, France, 27 June - 1 July, 2022
Year: 2022
Subjects: FLIGHT DYNAMICS
GNC
AVIONICS
DYNAMICS ANALYSIS
DEGRADED MODES

description: Over the last 20 years, miniaturization and New Space have appeared as the two leading trends in the field of satellite technologies and have therefore driven an important reshaping of the space launch market. In this context, the majority of satellites have changed drastically in typical dimension, mass and cost, causing, together with new target orbits, the necessity for newly adapted launch services. This has originated the opportunity for innovative solutions targeting higher orbital flexibility, multi-payload capability, shorter launch campaigns, higher launch frequency and lower costs, without compromising reliability and safety of mission with respect to people and properties. The innovation in the domain of the Flight SW enormously contributes to above scenario in terms of flexibility and missionization responsible for vehicle functions of Safety, Flight Manager and GNC. Regarding Safety, on-board autonomous safety systems have been under study and development for the last decade on most New Space initiatives, and have even reached the heavy launcher services, with the objective of reducing ground infrastructures and interfaces, operations campaign duration and inter-campaign preparation, such as training devoted to the safety mission, having a direct impact on costs. In terms of performance, on-board safety systems reduce the decision-making chain and increase the flexibility of the launch service through on-board flight SW missionization. In this scenario, this paper proposes a modular and configurable On-board Autonomous Safety SYStem (OASSYS) constituted by two modules: a diagnosis module that enables to monitor mission status (Launcher Dynamics, Impact Point/Area [1] and Vehicle Health Status) and the decision-making module (FLOS) based on fuzzy logic. The use of fuzzy logic approach enhances the flexibility and missionization of the system allowing it to adapt to mission requirements. The flight safety decision-making module requires awareness of mission and vehicle status as an input to apply the optimal safety configuration. The Flight Manager block provides with these inputs, as responsible for managing the FSW blocks, namely GNC and Safety, with respect to the mission. The Flight Manager is implemented by means of a finite state machine assessing the status of the vehicles propulsion and operative stage the flights atmospheric conditions, and the missions orbital conditions and safety. Furthermore, the Flight Manager allows soft adaptations of the nominal mission timeline in presence of perturbations, considering non-deterministic state transitions which are triggered by multivariate functions assessing in real-time the optimal conditions for the execution of the engines cutoff and ignition, and the stage release events. This study is integrated in the frame of activities H2020 project ENVOL (funded by the EC Grant Agreement 870385 lead by NAMMO), a project devoted to the design and demonstration of a hybrid propelled micro-launcher targeting LEO and SSO orbits at 800km providing services to payloads up to 200kg. GTD is responsible for the design and prototyping of the avionics and Flight SW, including the Flight Safety and Flight Manager blocks, subject of this paper, besides the GNC block. The design, development and validation follow a Processor-In-the-Loop approach, composed of a target machine simulating the physical models and interfacing a processor with real-time operating system embedding the Flight SW. The OASSYS is interfaced with the Navigation block [2], based on hybrid approach to monitor the dynamic state in the diagnostic module of the Safety block, as well as with the launcher model for the assessment of the systems status. Analogously, the Flight Manager block, other than its aforementioned interface with Flight Safety, is also interfaced to the GNC block as responsible for managing the states and performance of its internal modules through the flight phases and events. The results obtained from the testing and validation procedures confirm that the benefits of the autonomous on-board flight safety fulfil the New Space high level requirements on high flexibility, configurability and the capability of adapting to multiple mission profiles, multiple spaceport safety requirements and potentially to multiple launch services concepts other than vertical expendable, such as airborne and reusable.