Station-Keeping Optimization in Low Earth Orbit under Low-Thrust Propulsion with Eclipse Constraints.

This thesis examines how to keep a satellite in a stable orbit in Low Earth Orbit (LEO) using a continuous low-thrust engine. We specifically look at the challenges caused by shadow phases, when the satellite is in Earth’s shadow. The physical model is set up in a 3D spherical coordinate system and includes the effects of atmospheric drag. Because the engine can’t operate in the shadow, this eclipse constraint is a key factor in how we can control the satellite and what thrust strategy is needed. To handle environmental forces, we use the MSISE-00 model for atmospheric density. We also use SPICE data to accurately track the positions of the Sun and Earth, which helps us precisely determine when the satellite is in shadow. We created a Python software with a user-friendly graphical interface (GUI). This tool lets users easily set up initial parameters and view the optimized orbital paths. Our findings show how shadow constraints affect low-thrust station-keeping. We demonstrate that the available thrust must be adjusted and distributed along the sunlit parts of the orbit to maintain the satellite’s position. This method offers a useful way to design preliminary station-keeping strategies for real-world operations in LEO.