Challenge to Infinite Life Time Electric Propulsion using Single Crystals

2021 Fiscal Year Final Research Report

• Project/Area Number: 19K22020
• Research Category: Grant-in-Aid for Challenging Research (Exploratory)
• Allocation Type: Multi-year Fund
• Review Section: Medium-sized Section 24:Aerospace engineering, marine and maritime engineering, and related fields
• Research Institution: Japan Aerospace EXploration Agency
• Principal Investigator: Funaki Ikkoh 国立研究開発法人宇宙航空研究開発機構, 宇宙科学研究所, 教授 (50311171)
• Project Period (FY): 2019-06-28 – 2022-03-31
• Keywords: 電気推進 / ホローカソード / スパッタリング / 単結晶 / 長寿命

Outline of Final Research Achievements

Electric space propulsion (EP) such as ion thrusters and Hall thrusters exhausts a plasma jet to propel a spacecraft. EP's feature is high specific impulse, which means larger amount of delta-V is possible with the same propellant mass in comparison with conventional chemical propulsion. In this study, methods to drastically lower the erosion rate of a hollow cathode were tried experimentally. Although the effect of crystal structure on sputtering yield by xenon ion impact was not significant, it was found that the ion energy onto the orifice could be reduced via selecting appropriate orifice diameter and neutral density. By the latter approach life time in the order of several tens of thousand hours is expected.

Free Research Field

宇宙機推進工学

Academic Significance and Societal Importance of the Research Achievements

打ち上げから軌道制御までをすべてを燃費の良い電気推進機で実施する次世代衛星は、オール電化衛星と呼ばれ、その優れたペイロード搭載率から、2020年代人工衛星市場の主流になると予想されている。損耗の非常に小さいカソードオリフィス等素材設計が得られたことで、現在のスラスタ寿命制約を逃れ、自在な人工衛星運用や、軌道間輸送、惑星間輸送などの長期にわたるミッションの実現へと繋がり、挑戦的な意義を持つ。