Asteroid Flyby Cycler Trajectory Design Using Deep Neural Networks

TL;DR

This paper introduces a deep neural network-based surrogate model to efficiently design asteroid flyby cycler trajectories, significantly reducing computation time in mission planning.

Contribution

It presents a novel deep learning approach combined with pseudo-asteroids for rapid trajectory optimization in asteroid flyby missions.

Findings

Reduces computational time for flyby sequence search

Demonstrates applicability to JAXA's DESTINY+ mission

Provides an efficient database generation strategy

Abstract

Asteroid exploration has been attracting more attention in recent years. Nevertheless, we have just visited tens of asteroids while we have discovered more than one million bodies. As our current observation and knowledge should be biased, it is essential to explore multiple asteroids directly to better understand the remains of planetary building materials. One of the mission design solutions is utilizing asteroid flyby cycler trajectories with multiple Earth gravity assists. An asteroid flyby cycler trajectory design problem is a subclass of global trajectory optimization problems with multiple flybys, involving a trajectory optimization problem for a given flyby sequence and a combinatorial optimization problem to decide the sequence of the flybys. As the number of flyby bodies grows, the computation time of this optimization problem expands maliciously. This paper presents a new method to design asteroid flyby cycler trajectories utilizing a surrogate model constructed by deep neural networks approximating trajectory optimization results. Since one of the bottlenecks of machine learning approaches is the computation time to generate massive trajectory databases, we propose an efficient database generation strategy by introducing pseudo-asteroids satisfying the Karush-Kuhn-Tucker conditions. The numerical result applied to JAXA's DESTINY+ mission shows that the proposed method is practically applicable to space mission design and can significantly reduce the computational time for searching asteroid flyby sequences.