Discrete-Event Drag-Modulated Guidance Performance for Venus Aerocapture

Abstract

Drag modulation provides a straightforward approach to aerocapture trajectory control. In this paper, two guidance algorithms are assessed for Venus aerocapture: a predictive-trigger and a numerical predictor–corrector. A hybrid root finder is developed for both single- and multistage jettison. Architecture performance is assessed using Monte Carlo methods. Two apoapsis altitude targets, 2000 and 10,000 km, are considered alongside two entry flight-path angles, and . The hybrid root finder improved targeting accuracy and robustness compared with a standard bisection technique. Each of the guidance algorithms performed better for shallower entry angles. The benefit of multi-event jettison architectures is analyzed in this study. A second jettison event is shown to significantly improve apoapsis targeting accuracy, whereas a third jettison event further improves this accuracy, but to a lesser degree, demonstrating multistage jettison’s potential to improve aerocapture robustness.