Stability and Robustness Analysis of Reference Drag-following Reentry Guidance

This study analyzes the stability and robustness of the reference drag-following reentry guidance algorithm. Although the drag-following method has been successfully applied to the reentry guidance of the space shuttle, there is a lack of study on systematic organization and stability/robustness analysis of this method. Therefore, this study details the reference drag-following guidance algorithm and its design methodology, and analyzes its characteristics and performance under various disturbances and model uncertainties for application to next-generation reentry vehicles. To effectively demonstrate and analyze this guidance algorithm, we utilize a dynamic model of a reentry vehicle with the curvature and rotation of the Earth and account for model uncertainties in atmospheric density and aerodynamic coefficients. Extensive numerical simulations of reentry flight are performed to analyze the effectiveness and robustness of the drag-following method.