三田 信

第1回観測ロケットシンポジウム（2018年7月17日-18日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000127009レポート番号: Ⅲ-3

第1回観測ロケットシンポジウム（2018年7月17日-18日. 宇宙航空研究開発機構宇宙科学研究所（JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000127016レポート番号: V-2

Hayabusa2 was launched on 3 December 2014 on an H-IIA launch vehicle from the Tanegashima Space Center, and is, at the time of writing, cruising toward asteroid 162137 Ryugu (1999JU3). After reaching the asteroid, it will stay for about 1.5 years to observe the asteroid and collect surface material samples. The light detection and ranging (LIDAR) laser altimeter on Hayabusa2 has a wide dynamic range, from 25 km to 30 m, because the LIDAR is used as a navigation sensor for rendezvous, approach, and touchdown procedures. Since it was designed for use in planetary explorers, its weight is a low 3.5 kg. The LIDAR can serve not only as a navigation sensor, but also as observation equipment for estimating the asteroid's topography, gravity and surface reflectivity (albedo). Since Hayabusa2 had a development schedule of just three years from the start of the project to launch, minimizing development time was a particular concern. A key to shortening the development period of Hayabusa2's LIDAR system was heritage technology from Hayabusa's LIDAR and the SELENE lunar explorer's LALT laser altimeter. Given that the main role of Hayabusa2's LIDAR is to serve as a navigation sensor, we discuss its development from an engineering viewpoint. However, detailed information about instrument development and test results is also important for scientific analysis of LIDAR data and for future laser altimetry in lunar and planetary exploration. Here we describe lessons learned from the Hayabusa LIDAR, as well as Hayabusa2's hardware, new technologies and system designs based on it, and flight model evaluation results. The monolithic laser used in the laser module is a characteristic technology of this LIDAR. It was developed to solve issues with low-temperature storage that were problematic when developing the LIDAR system for the first Hayabusa mission. The new module not only solves such problems but also improves reliability and miniaturization by reducing the number of parts.

第4回宇宙ナノエレクトロニクスワークショップ(2016年12月15日. 宇宙航空研究開発機構宇宙科学研究所(JAXA)(ISAS)), 相模原市, 神奈川県著者人数: 18名資料番号: SA6000092005レポート番号: 5

大気球シンポジウム 平成28年度（2016年11月1-2日. 宇宙航空研究開発機構宇宙科学研究所 (JAXA)(ISAS)）, 相模原市, 神奈川県資料番号: SA6000057018レポート番号: isas16-sbs-018

X-ray reflectivity of an ultra light-weight X-ray optic using MEMS technologies was measured in two different energies (0.28 keV and 1.49 keV). The obtained reflectivities can be understood by considering the mirror surface structures.

MEMS技術を用いて2次元走査型LIDAR用のスキャナを開発した.赤色のレーザー光を用いて走査実験を行ったところ約5度走査することができた.

We present our development of novel light-weight and low-cost micro-pore X-ray optics based on the Micro Electro Mechanical Systems (MEMS) technologies. We successfully fabricated X-ray mirror chips with surface roughness less than several nm and an accurately defined optic mount. Our studies suggest this type of optics is a promising device for X-ray optics in many research fields such as space research, nuclear physics, and microanalysis. (c) 2007 Elsevier B.V. All rights reserved.

This paper describes the on-orbit results and lessons learned of the small scientific satellite "INDEX" (REIMEI) for aurora observation and demonstration of advanced satellite technologies. REIMEI is a small satellite with 72kg mass, and is provided with three-axis attitude controlled capabilities for aurora observation. REIMEI was launched into a nearly sun synchronous polar orbit on Aug. 23^<rd>, 2005 (UT) from Baikonur, Kazakhstan by Dnepr rocket. REIMEI satellite functions satisfactorily on the orbit. Three axis control is achieved with accuracy of 0.05 deg. Multi-spectrum images of aurora are taken with 8Hz rate and 2 km spatial resolution to investigate the aurora physics. REIMEI is a small scientific satellite for aurora observation and advanced satellite technologies, and was launched into a nearly sun synchronous polar orbit on Aug. 23^<rd>, 2005 (UTC) from Baikonur, Kazakhstan by Dnepr rocket. REIMEI satellite functions satisfactorily on the orbit. The three-axis attitude control is achieved with accuracy of 0.05deg. REIMEI is performing the simultaneous observation of aurora images as well as particle measurements. REIMEI indicates that even a small satellite launched as a piggy-back can successfully perform the unique scientific mission purposes.

We report on our development of X-ray optics using anisotropic wet etching of ssilicon wafers. Both X-ray mirrors and an optics mount are fabricated fully using the MEMS technologies. © 2006 IEEE.

本研究では,宇宙探査機用2次元走査LIDAR(LIght Detection And Ranging)のためのMEMSミラーを用いた送信光学系について提案している.現在,ISAS/JAXAにて開発されている2次元走査LIDARでは,φ10°の走査範囲に離散的アレー状に受信視野(φ1.5mrad)が配置されている.送信システムは離散的に配置された受信視野に対して,共振駆動によって2軸方向に回転可能なMEMSミラーでPassive Q-SW YAGレーザのパルスを発射していくシステムとなっている.本報告では,共振駆動するMEMSミラーの位置の決定手法を提案し,500Hz程度で共振駆動するミラーを用いて0.5mrad以下の決定精度が得られることを実験的に確認した.

A novel micromachined actuator which is developed to produce precise and unlimited displacement. The actuator is driven by impact force between a silicon micro-mass and a stopper. A suspended silicon mass is encapsulated between glass plates and driven by electrostatic force. By hitting a stopper, it generates impact force to drive the whole actuator in a small step (&acd;10nm). It is a micromachined and electrostatic version of the impact-drive actuator. The overall dimension of the device is 3mm×3mm. The driving voltage is 100V and average speed is 2.7μm/s. The total thickness is 600μm.

A new micromachining process for large-scale optical cross-connects is presented. It satisfies the high-accuracy optical alignment required for free-space optics. A self-aligned batch-process allowing the simultaneous fabrication of vertical mirrors and fiber guides is performed with only one-mask. This process is based on bulk micromachining of (100) silicon. A first demonstration is performed on a 2 x 2 elementary cell then, it is extended to the fabrication of larger mirror arrays. Promising performances such as insertion loss lower than 0.5 dB, sub-millisecond switching time (0.3 ms) and reliable operation (more than 20 million cycles) are demonstrated on a bypass switch. An improved fabrication process, leading to an increase of integration density is also presented. It is based on the combination of deep dry-etching and anisotropic wet-etching.