A low-thrust-enabled SmallSat heliophysics mission to Sun-Earth L5

We present an approach to enable SmallSat mission concepts to the Sun-Earth (SE) L 5 Lagrange point in support of advancing our understanding of solar processes and weather monitoring capabilities by addressing one of the primary challenges of such a mission: traveling to this distant region with limited propulsive capability. Heliophysicists have long been interested in missions to SE L 5 , which trails behind the Earth in its orbit, due to the capability for viewing solar and interplanetary phenomena. Consequently, a spacecraft orbiting in the vicinity of SE L 5 would observe the Sun before it rotates into Earth nadir and provide early warning of solar activity. Although SmallSats have emerged as an effective and low-cost platform for space-based science and exploration, operational and mission constraints create significant challenges during the trajectory design process. For instance, the miniaturization of electrospray and ion thrusters render low-thrust propulsion systems an enabling technology for upcoming small satellite missions. However, such systems supply only a low acceleration over limited time intervals. Furthermore, the deployment conditions associated with a SmallSat are typically determined by the primary mission and may evolve frequently throughout the lifecycle of the mission. These regular updates may result in deviations from an individual reference trajectory that are too large for a low-thrust propulsion system to overcome, thereby necessitating a complete trajectory redesign. Together, these operational and mission constraints severely impact the geometry and availability of feasible trajectories that deliver a low-thrust-enabled SmallSat from an uncertain deployment state to the vicinity of SE L 5 . In fact, these challenges necessitate a rapid and well-informed procedure that leverages dynamical systems techniques for trajectory design. We summarize and demonstrate such an approach within this paper.