Reachable Set of Low-Delta-v Trajectories Following a Gravity-Assist Flyby

Abstract

Flyby tours are challenging to design due to the extraordinarily large search space. A single algorithm is proposed to answer the question of what low-cost, post-flyby options exist for a spacecraft arriving at a flyby body. The algorithm a) considers the full domain of reachable bodies and transfer types including even- and odd-[Formula: see text] resonant ballistic, nonresonant ballistic, and [Formula: see text]-infinity leveraging; b) identifies families of solutions instead of just single points; and c) structures the search to only seek solutions within a [Formula: see text] threshold. This algorithm extends and integrates these state-of-the-art characteristics, and is designed to rapidly inform an outer-loop pathfinding scheme for flyby tour design. Detailed examples of resulting solutions and families are provided for multiple variations of three different use case scenarios, including tours in the Jupiter, Saturn, and sun systems. As a representative example in the Jupiter system starting at Callisto, the algorithm takes on the order of 0.1 s to find over 500 solutions with [Formula: see text] costs below [Formula: see text] organized into nearly 70 families, all either returning to Callisto or proceeding to Ganymede.