Realization of CO2 Ion Engines for Resource-Saving Orbital Operation of Manned Space Structures

2022 Fiscal Year Final Research Report

• Project/Area Number: 20K04928
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 24010:Aerospace engineering-related
• Research Institution: Tokyo Metropolitan College of Industrial Technology
• Principal Investigator: Nakano Masakatsu 東京都立産業技術高等専門学校, ものづくり工学科, 教授 (90315169)
• Co-Investigator(Kenkyū-buntansha): 各務 聡 東京都立大学, システムデザイン研究科, 教授 (80415653)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: イオンエンジン / 二酸化炭素 / 有人宇宙構造物 / 省資源軌道運用 / 軌道保持

Outline of Final Research Achievements

A study was conducted on an ion engine that utilizes carbon dioxide for the resource-saving orbital operation of a manned space structure. Based on mission analysis, it was estimated that a specific impulse of approximately 2000 s is required for precise control and operation of the manned space system, and the feasibility of the ion engine was evaluated. A global model of the carbon dioxide ion engine was created for the first time, and experiments were conducted on the performance of a small ion source, such as beam extraction. Grid fabrication through ion beam processing was also carried out due to the limitations in improving propellant utilization efficiency. The thrust was evaluated through theoretical estimation as well as measurements using a thrust stand. Based on these findings, although further performance improvements are necessary, it was concluded that an ion engine utilizing carbon dioxide is compatible with the control of manned space structures.

Free Research Field

宇宙推進工学

Academic Significance and Societal Importance of the Research Achievements

イオンエンジンなどの電気推進において，キセノンの代替となる推進剤への切り替えは喫緊の課題である．キセノンなどの貴ガスと異なり，二酸化炭素のような分子性の推進剤をイオンエンジンに用いるには，分子性プラズマに関する新たな知見が要求されるとともに，耐久性能評価のために放電室・電極材料の表面物理に対する理解も必要である．宇宙開発には多額のコストがかかるとともにロケット打ち上げ等による環境負荷も懸念されている．人間や動植物からの排出物である二酸化炭素の有効活用は省資源での宇宙開発を実現し，宇宙開発における SDGsにも寄与するものであり社会的な意義が高い．