Shallow Encounters' Impact on Asteroid Deflection Prediction and Implications on Trajectory Design

TL;DR

This paper evaluates the accuracy of analytical models in predicting asteroid deflection trajectories, highlighting the significant impact of distant perturbing encounters and providing guidelines for improved mission planning.

Contribution

It offers a detailed comparison between analytical and numerical models, revealing the effects of shallow encounters on deflection predictions and proposing practical guidelines for trajectory design.

Findings

Distant perturbing encounters can significantly alter asteroid trajectories.

Analytical models may underestimate the impact of shallow encounters.

Guidelines are proposed to mitigate encounter effects in mission planning.

Abstract

Analytical approximations are commonly employed in the initial trajectory design phase of a mission to rapidly explore a broad design space. In the context of an asteroid deflection mission, accurately predicting deflection is crucial to determining the spacecraft's trajectory that will produce the desired outcome. However, the dynamics involved are intricate, and simplistic models may not fully capture the system's complexity. This study assesses the precision and limitations of analytical models in predicting deflection, comparing them to more accurate numerical simulations. The findings reveal that encounters with perturbing bodies, even at significant distances (a dozen times the radii of the sphere of influence of the perturbing planet), can markedly disturb the deflected asteroid's trajectory, resulting in notable disparities between analytical and numerical predictions. The underlying reasons for this phenomenon are explained, and provisional general guidelines are provided to assist mission analysts in addressing such occurrences. By comprehending the impact of shallow encounters on deflection, this study equips designers with the knowledge to make informed decisions throughout the trajectory planning process, enhancing the efficiency and effectiveness of asteroid deflection missions.