Power Generation on a Bare Electrodynamic Tether during Debris Mitigation in Space

Kan Xie,Xiangyang Liu,Qimeng Xia,Ningfei Wang,Haoxiang Yuan,Zhiwen Wu,Fuwen Liang,Zun Zhang,Enrico C Lorenzini

doi:10.1155/2021/8834196

Abstract

Power generation can be realized in space when current is induced on a bare electrodynamic tether system. The performance of power generation is discussed based on a debris mitigation mission by numerical simulation in the paper. A Li-ion battery subsystem is used to complete the energy conversion—harvest and supply the energy. The battery can provide 10–300 W average electric power continuously during several hundred hour mission time. The energy conversion efficiency ranges from 1% to a maximum value 30%. With constant power consumption on board, the battery operation generally experiences a discharging phase, a charging phase, and a stable phase. The first two phases determine the mission risk coefficient. The heating problem in the stable phase cannot be ignored. The optimization of battery design and tether design should be considered for each debris mitigation mission. An extra control circuit or small battery voltage with large capacity for battery design is suggested to eliminate the stable phase. Wide or long tether designs are more appropriate for mission with high or low power demands on board, respectively. The power generation is affected by the system mass and the mission orbit parameters.

Highlights

The bare electrodynamic tether is a promising device with which to expand the range of a space mission [1]
The bare conductive tether is used as the anode to absorb electrons and is much more efficient and easier to implement than previous strategies such as anodic plasma contactors or spherical collectors
As the bare electrodynamic tether enables a large current, it can complete many space missions better in LEO (Low Earth Orbit) with high specific impulse and non-or-less propellant consumption when compared to traditional systems [3, 4]

Summary

Introduction

The bare electrodynamic tether is a promising device with which to expand the range of a space mission [1]. It utilizes a bare conductive tether and an electron emission device to complete the charge exchange with the space plasma. As the bare electrodynamic tether enables a large current, it can complete many space missions better in LEO (Low Earth Orbit) with high specific impulse and non-or-less propellant consumption when compared to traditional systems [3, 4]. The bare electrodynamic tether can produce the induced current and significant drag, leading to two impressive functions: power can be generated on board by a load and the system can transfer to a lower orbit.

Tether system begins operation

System Model and Numerical Simulation Settings

Results

Bare tether

Results and Analysis

Conclusions