Advanced study on atmospheric reentry blackout mitigation using a large plasma wind tunnel

2022 Fiscal Year Final Research Report

• Project/Area Number: 17KK0123
• Research Category: Fund for the Promotion of Joint International Research (Fostering Joint International Research)
• Allocation Type: Multi-year Fund
• Research Field: Aerospace engineering
• Research Institution: Hokkaido University
• Principal Investigator: Takahashi Yusuke 北海道大学, 工学研究院, 准教授 (40611132)
• Project Period (FY): 2018 – 2022
• Keywords: 惑星大気再突入 / 通信ブラックアウト / 空力加熱 / プラズマ中の電磁波伝播 / アーク加熱風洞 / 表面触媒効果 / エアフィルム効果

Outline of Final Research Achievements

The radio-frequency (RF) blackouts that occur on spacecraft during atmospheric reentry hinder accurate landing-site prediction and increase recovery costs Thus, it is important to reduce these blackouts. In this study, I proposed novel RF blackout reduction schemes based on the surface catalysis effect and the air film effect. Collaboration with researchers at the German Aerospace Center (DLR), where I was staying during this study, and related discussions played an important role in this process. The reentry environment was reproduced using a large computer and a large plasma wind tunnel to assess the feasibility of the novel technique and to conduct numerical and experimental verification, elucidating the mechanism leading to the reduction.

Free Research Field

高速流体・高温気体力学

Academic Significance and Societal Importance of the Research Achievements

近年の宇宙輸送手段の進展から、宇宙開発や小型衛星・超小型衛星の利用、宇宙から地上に資料などを持ち帰る需要・機会は大きく増大していくと期待される。これら宇宙ミッションにおいて大気再突入は避けて通れない過程である。再突入時において宇宙機は高速・高温の極限的環境に置かれ、強い空力加熱や空力不安定など様々な問題が生じる。通信ブラックアウトもその１つであり、高精度着地点予測の妨げになるとともに回収コストの増大を招く。本研究では新しいブラックアウト低減化技術を提案、実証し、メカニズム解明を行った。この成果は空力加熱低減化技術にも発展し可能性を有し、多様な宇宙ミッション創出に寄与することが期待される。