Analysis of NEO Deflection Using Planetary Sunshade Sailcraft for Planetary Defence

Kurzfassung

In response to the urgent climate crisis, the Planetary Sunshade Foundation envisions deploying a high number sunshade sailcraft, ranging from hundreds of millions to 1.5 billion units, near Sun-Earth Lagrange point 1. Assuming these sunshade sailcraft are already deployed in interplanetary space, this space-based geoengineering initiative, holds potential not only for addressing climate concerns but also for deflecting potentially hazardous asteroids by applying the kinetic impactor energy technique. This study focuses on designing deflection mission scenarios for these sailcraft arrangements. The primary objective is to determine the required sailcraft mass and quantity within a specific time frame to achieve a deflection distance of two Earth radii. Target body for the analysis is the asteroid 2023 PDC, a fictitious asteroid which is designed for the scenario within the 8th Planetary Defence Conference 2023. A hybrid approach is employed to find the best sailcraft trajectories among the analysed scenarios. Initial deflection simulations using Poliastro, a Python library for astrodynamics, while InTrance, integrating neural networks, drives the optimisation process. This methodology is applied to two distinct sunshade sailcraft configurations introduced by Fuglesang et al. in [32]. The findings demonstrate a deflection efficiency of 10 metres per kilogram impacting sail mass for the first sailcraft arrangement and 5 metres per kilogram for the second. In contrast the analytically approximated case achieves an efficiency of 1.5 metres per kilogram. This investigation underscores the substantial impact of the applied launch window analysis beyond extended deflection time on enhancing efficiency. Therefore the significant mass in interplanetary space, a result of the planetary sunshade deployment, provides a strategic edge for the kinetic energy impactor technique.