Reduced Lift-to-Drag Vehicle Concepts for Neptune Aerocapture

A wide body of research is focused on aerocapture to facilitate orbital insertion. The aerocapture
maneuver consists of a single pass through a target planet’s upper atmosphere to reduce kinetic energy
through aerodynamic forces. Upon atmospheric exit, the vehicle flies a Keplerian orbit to apoapsis
where a series of small correction burns are performed. Studies of aerocapture at Neptune have
confirmed significant mass savings over fully-propulsive methods. However, aerocapture requires
active guidance during the atmospheric phase of flight and often requires large control margin that
cannot be provided by typical entry vehicles with low lift-to-drag ratios. The goal of this study is to
apply modern predictor-corrector guidance algorithms to enable the use of low lift-to-drag vehicle concepts for aerocapture at Neptune.