Makoto Mita

1st Sounding Rocket Symposium (July 17-18, 2018. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan

1st Sounding Rocket Symposium (July 17-18, 2018. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan

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.

4th Workshop of Nano-Electronics For Space Use (December 15, 2016. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan

Balloon Symposium 2016 (November 1-2, 2016. Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency (JAXA)(ISAS)), Sagamihara, Kanagawa Japan

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.

We have developed a novel MEMS scanner of the laser radar for landing to the planet. The scanner has to overcome launching vibration and impact and can be used in harsh environment of the space

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.

A transmission optics system for a 2D scanning LIDAR system for a deep space explore with a MEMS mirror has been proposed. 2D scanning LIDAR that developed in ISAS/JAXA has many narrow field of views that are placed dispersion array in scanning angle at φ10°. A transmission system of 2D LIDAR has a Passive Q-SW YAG leaser as a transmitter. It shot its leaser pulse on a field of view(φ1.5mrad) of receiver system. In this result, the detection method of the MEMS mirror that is driving in 500Hz has been proposed. From experiment, we found the accuracy of the method was less than 0.5mrad.

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.