Near-Earth Asteroid Capture via Using Lunar Flyby plus Earth Aerobraking

Yirui Wang,Mingtao Li

doi:10.3390/universe7090316

Abstract

Capturing Near-Earth Asteroids (NEAs) in the Earth-Moon system is a potential method of future space exploration and resource utilization. In order to make the captured NEA easily rendezvoused by spacecrafts, it is expected to capture the asteroid in a low-energy and low-inclination orbit. Lunar flyby and Earth aerobraking have been proved to be effective energy-saving methods in asteroid retrieval missions. Based on the Earth aerobraking capture strategy, if a lunar flyby process is performed before the asteroid enters the atmosphere, the thermal ablation of the asteroid in the atmosphere is expected to be alleviated. This paper proposes a lunar flyby plus Earth aerobraking method to capture an NEA. Using Geostationary Transfer Orbit (GTO) as the target orbit, the efficiency of three different capture strategies (direct capture strategy, Earth aerobraking capture strategy and lunar flyby plus Earth aerobraking capture strategy) are compared. Compared to the Earth aerobraking capture strategy, simulation results show that the main advantage of the lunar flyby plus Earth aerobraking capture strategy is that the mass loss ratio can be reduced (15 real asteroids are used as examples and mass loss ratio can be reduced by 0.98–3.39%). For example, for an asteroid with a diameter of 5 m, the mass is about 170.17 tons (with a density of 2.6g/cm3), reducing the mass loss ratio by 1% means that 1701.7 kg of the asteroid materials can be saved. Meanwhile, if the asteroid has a suitable phase for lunar flyby, while reducing the mass loss ratio, the fuel consumption can also be reduced. Furthermore, the conditions that do not require maneuvering between the lunar flyby and Earth aerobraking are preliminarily discussed. During the preliminary design stage of asteroid retrieval missions, compared with the Earth aerobraking capture strategy, lunar flyby plus Earth aerobraking capture strategy provides a potentially effective option for reducing the mass loss and the fuel consumption.

Highlights

Capturing Near-Earth Asteroids (NEAs) in the Earth-Moon system is a potential method of future space exploration and resource utilization
In order to reduce the mass loss of the asteroid due to the thermal ablation, this paper proposes performing a lunar flyby process before the asteroid enters the atmosphere, named lunar flyby plus
The Geostationary Transfer Orbit (GTO) is used as the target orbit to compare the efficiency of three different capture strategies

Summary

Introduction

Capturing Near-Earth Asteroids (NEAs) in the Earth-Moon system is a potential method of future space exploration and resource utilization. Lunar flyby and Earth aerobraking have been proved to be effective energy-saving methods in asteroid retrieval missions. This paper proposes a lunar flyby plus Earth aerobraking method to capture an NEA. During the preliminary design stage of asteroid retrieval missions, compared with the Earth aerobraking capture strategy, lunar flyby plus. Earth aerobraking capture strategy provides a potentially effective option for reducing the mass loss and the fuel consumption. In addition to in situ resource utilization, humans are considering the use of energy-saving transfer to capture an NEA [2,3]. Space-based commerce may develop within the few decades, including manufacturing, solar power stations, and space tourism [3]

Results

Discussion

Conclusion