1. Strategies for hollow cathode command in short electrodynamics tether-based deorbit devices.
- Author
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Sharifi, G. and Sánchez-Arriaga, G.
- Subjects
- *
CATHODES , *MONTE Carlo method , *ELECTRIC currents , *SPACE debris , *PLASMA flow , *MICROBIAL fuel cells - Abstract
Heaterless hollow cathodes are a promising solution for reaching a good cathodic contact in electrodynamic tether systems. However, these cathodes cannot keep the plasma discharge if the electric current I C is below a threshold I m i n. If the tether is short, and to save power and expellant, an appropriate command strategy is needed to ensure that the cathode is triggered in conditions satisfying I C > I m i n . This study investigates four command strategies, including two fully autonomous approaches (one based on satellite position and the other on local plasma density) and two strategies involving ground segment access, differing in command generation location (ground segment and on-board computer). The success rates of the four strategies were studied though numerical simulation and for the specific scenario of the E.T.PACK demonstration mission. The results demonstrate that, as compared to continuous operation of the hollow cathode, the proposed strategies reduce propellant wastage by a factor between 5 and 10. The strategy requiring ground segment access and with the onboard computer making the command decision has the highest success rate (94%). Among the autonomous configurations, the strategy based solely on local plasma density achieves the highest success rate (69%). Additionally, the impact of sensor accuracy on success rates was assessed via Monte Carlo analysis. The command strategy relying on plasma density measurement is the most sensitivity strategy, with a 10% decrease in success rate due to sensor uncertainty. • Four strategies for commanding the hollow cathode of short electrodynamic tethers are proposed. • Duty cycle and rate of success are used to assess the performance of the strategies. • The two strategies involving contact with the ground segment have the best performance. • The two autonomous strategies only involve one onboard sensor and provide acceptable performance. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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