[P-CG21] 宇宙・惑星探査の将来計画と関連する機器開発の展望

[PCG21-14] Analysis of Isotopic and Molecular Compositions of Materials from a Jupiter Trojan Asteroid Using High Resolution Mass Spectrometry (HRMS) in the Solar Power Sail OKEANOS Mission

*癸生川 陽子¹、岡田 達明^2,3、青木 順⁴、伊藤 元雄⁵、河井 洋輔⁴、横田 勝一郎⁴、松本 純²、圦本 尚義^6,2、矢野 創²、Cottin Hervé ⁷、Grand Noel ⁷、森 治²、The OKEANOS team (1.横浜国立大学、2.宇宙航空研究開発機構、3.東京大学、4.大阪大学、5.海洋研究開発機構、6.北海道大学、7.LISA, Université Paris-Est Créteil)

キーワード：木星トロヤ群小惑星、質量分析、OKEANOS

The OKEANOS (Outsized Kite-craft for Exploration and AstroNautics in the Outer Solar system) is a candidate for the upcoming strategic middle-class space exploration to rendezvous with and land on a Jupiter Trojan asteroid using a Solar Power Sail (SPS). The mission concept includes in-situ sampling analysis of the surface and subsurface (up to 1 m) materials of a Jupiter Trojan asteroid using a multi-turn time-of-flight type high-resolution mass spectrometry (HRMS) system.

We plan to analyze isotopic and elemental compositions of volatile materials from organic matter, hydrated minerals, and ice, in order to understand origin and evolution of the Jupiter Trojan asteroids. It will provide insights into (1) planet formation/migration theories, (2) evolution and distribution of volatiles and organic matter in the Solar System, and (3) evolutional history of the Solar System small bodies beyond the snow line.
The HRMS system is under development aiming to measure H, N, C, O isotopic compositions and elemental compositions of organic compounds. The system also includes various pre-MS procedures; stepwise heating up to 600ºC, gas chromatography (GC), and high-temperature pyrolysis with catalyst to decompose the samples into simple gaseous molecules (e.g., H₂, CO, and N₂) for isotopic ratio analysis.