日本地球惑星科学連合2023年大会

講演情報

[E] 口頭発表

セッション記号 P (宇宙惑星科学) » P-CG 宇宙惑星科学複合領域・一般

[P-CG18] 宇宙・惑星探査の将来計画および関連する機器開発の展望

2023年5月22日(月) 13:45 〜 15:00 105 (幕張メッセ国際会議場)

コンビーナ:横田 勝一郎(大阪大学・理学研究科)、坂谷 尚哉(JAXA 宇宙科学研究所)、小川 和律(宇宙航空研究開発機構)、桑原 正輝(立教大学)、座長:桑原 正輝(立教大学)

14:00 〜 14:15

[PCG18-06] BepiColombo みお 搭載磁場観測器 MGF の運用と機上データ処理

*松岡 彩子1、Baumjohann Wolfgang2、Magnes Werner2、Auster Hans-Ulrich3、篠原 学4田中 良昌5藤本 晶子6、Schmid Daniel2、Fischer David2、Narita Yasuhito2松島 政貴7村上 豪8 (1.京都大学 理学研究科 地磁気世界資料解析センター、2.The Space Research Institute, OeAW、3.Technical University of Braunschweig、4.鹿児島工業高等専門学校、5.国立極地研究所、6.九州工業大学情報工学部、7.東京工業大学、8.宇宙航空研究開発機構 宇宙科学研究所)

キーワード:磁力計、水星、ベピコロンボ

By BepiColombo mission we aim to understand the essential properties of the Herman intrinsic magnetic field and physical process occurring in the Herman magnetosphere. To achieve our aims, we installed a dual magnetometer on Mercury Magnetospheric Orbiter (MMO, MIO), outboard (MGF-O) and inboard (MGF-I) magnetometers, which are developed by European and Japanese groups, respectively. One of the purposes of dual magnetometer is the redundancy, in addition to the separation of the artificial magnetic signal from the natural signal. The two magnetometers are operated independently for the complete redundancy, while the onboard software for the data processing and the output data format are exactly same. Since the telemetry budget for the MIO MGF is strictly limited, the onboard software pre-processes the data (e.g., fitting to the spin-period sinusoidal variation and definition of the least-significant-bit according to the field intensity) and effectively compresses the data before transmitting to the Earth.
BepiColombo was launched in October 2018 and is now cruising in the interplanetary space. It will be inserted into the orbit around Mercury in 2025 after flybys with the Earth, Venus, and Mercury. The MGF-O and MGF-I sensors are placed at the tip and in the middle, respectively, of the 5m long MAST of the MIO spacecraft. During the cruising, the MAST is stored in a container, and the two sensors are located nearby the surface of the spacecraft. Although the magnetic noise radiated from the MIO spacecraft is well restrained, the sensors are considerably interfered by the components on MIO. Moreover, since MIO, MPO (Mercury Planetary Orbiter) and a transfer module (MTM) are stacked during the cruising, MGF sensors suffer strong magnetic noise from MPO and MTM as well. Nevertheless both MGF-O and MGF-I are operated and measure the magnetic fields at flyby events. Some of the interference noise emerge as the difference between MGF-O and MGF-I data, and can be distinguished also by the comparison with the magnetic field data from MPO. The MGF team is making much efforts to evaluate and remove the interference noise so that we could identify natural phenomena in the space around planets. (The details about the data 'cleaning' will be presented in separated talks)
In this talk we present the onboard data processing for MIO MGF, report the operation of the magnetometers at flyby events, and discuss the perspectives about the observation in the orbits around Mercury.