🤖 AI Summary
This study addresses the challenge of achieving both high accuracy and computational efficiency in solar radiation pressure (SRP) modeling for orbit propagation, particularly for spacecraft with complex geometries or articulated solar arrays. To overcome this, the authors propose a Vulkan-based GPU-accelerated framework that integrates a ray-tracing physical model with dynamic solar array orientation coupling, enabling, for the first time, efficient online computation of high-fidelity SRP forces. The work also systematically evaluates the applicability of precomputed interpolation strategies. Experimental results demonstrate that the proposed approach incurs less than 5×10⁻⁴ relative error compared to a reference OpenGL implementation while accelerating individual SRP computations by 9.4× and full orbit propagation by 15.2×, thereby substantially reducing long-term orbital errors.
📝 Abstract
Solar Radiation Pressure (SRP), the force exerted by photons emitted by the Sun, is one of the main non-gravitational perturbations affecting spacecraft trajectories, making its accurate modeling essential for high-fidelity orbit propagation. While physically-based ray-tracing models improve SRP accuracy, their computational cost becomes a limitation during numerical integration, where the SRP force must be evaluated repeatedly throughout the trajectory propagation. This paper investigates the integration of high-fidelity SRP models into orbit propagation through two complementary contributions: a Vulkan-based GPU implementation that accelerates direct SRP evaluation, and an extension of the SRP model to account for the dynamic orientation of solar panels. These contributions are evaluated independently through orbit propagation experiments, while a precomputed SRP interpolation strategy (SPAD) is included as an alternative approach for reducing computational cost through offline sampling and interpolation. Numerical validation shows that the Vulkan implementation preserves the accuracy of the original OpenGL-based method, showing relative differences below $5\times10^{-4}$ while achieving speed-ups of up to 9.4 for individual SRP computations and up to 15.2 for complete orbit propagation, particularly for geometrically complex spacecraft. The movable solar panel model shows that neglecting panel motion can produce significant long-term propagation errors, especially for spacecraft with large articulated solar panels, while introducing only a moderate computational overhead. Based on the experimental evaluation, this work concludes with practical guidelines for integrating high-fidelity SRP models into orbit propagation frameworks, identifying the scenarios under which interpolation-based methods are sufficient and when online high-fidelity SRP computation is justified.