Contingency Analysis for Low-thrust Missions (CALM)

Low-thrust spacecraft trajectory optimization consists of defining a nominal solution that obeys known constraints and minimizes the spacecraft propellant mass used. A major deficiency with these traditional methods is that it is difficult to incorporate missed thrust events, spacecraft failure modes, or other mission-specific anomalies in the mission planning phase. Such anomalies could include the spacecraft going into safe mode, missing a tracking pass from Earth, or experiencing an off-nominal operational state such as using the wrong thrusting power mode or a thruster firing malfunction. Experienced engineers use intuition and guesswork to arrive at solutions manually that are robust to failure modes, but this ad-hoc approach typically comes at the expense of the time it takes for trajectory optimization. There is currently no industry standard to account for anomalous activities or failure modes for low-thrust and dynamically sensitive missions. This solution aims to address this specific deficiency in the mission planning process. The proposed solution is named CALM or Contingency Analysis for Low-thrust Missions.nbsp; In response to the 2023 NASA SBIR Phase II solicitation subtopic H9.03, ldquo;Flight Dynamics and Navigation Technologies,rdquo; Advanced Space, LLC proposes to develop a mission design and planning tool that uses operational algorithms to mitigate the impact of anomalies and missed thrust events for low-thrust and dynamically sensitive missions. The software tool is an extension of the Virtual Swarm Method (VSM) for low-thrust trajectory optimization to maximize the missed-thrust recovery margin. The tool will be used to generate a multitude of spacecraft trajectories simultaneously to determine the worst-case scenarios to account for margins in the mission design. The results will provide trajectories and thrust arcs from failure modes, inform mass and propellant margins, and contribute to mission risk analysis and mitigation.nbsp;