坂東 信尚

A 6U CubeSat “OMOTENASHI” was developed to be the world's smallest moon lander. It was launched by NASA's SLS Artemis-1 on November 16, 2022. However, because of the spacecraft anomaly, the battery was depleted and the communication with the spacecraft had been lost. After we gave up the moon landing experiment, we have been conducting a search and rescue operation till September 2023. But it was unsuccessful, unfortunately. In this article, the mission objective, the spacecraft design, the planed mission scenario, and the in-orbit operation results are presented. Additionally, lessons learned from the development and the in-orbit operation are presented.

This paper describes a method providing active vibration control of multiple mechanical coolers for space applications. Typical observation satellites have multiple mechanical coolers and their induced micro vibrations degrade pointing accuracy and cooler efficiency. In order to reduce such the vibration, active control is proposed. However, in the conventional control method for mechanical coolers, only considers the vibration of a single cooler and single axis has considered. Here we propose a method to simultaneously control the vibration of a satellite equipped with multiple mechanical coolers. We will discuss the condition of controllability, and actuator position and direction, and present the result of a simulation study.

The X-Ray Imaging and Spectroscopy Mission (XRISM) is the successor to the 2016 Hitomi mission that ended prematurely. Like Hitomi, the primary science goals are to examine astrophysical problems with precise high-resolution X-ray spectroscopy. XRISM promises to discover new horizons in X-ray astronomy. XRISM carries a 6 x 6 pixelized X-ray micro-calorimeter on the focal plane of an X-ray mirror assembly and a co-aligned X-ray CCD camera that covers the same energy band over a large field of view. XRISM utilizes Hitomi heritage, but all designs were reviewed. The attitude and orbit control system were improved in hardware and software. The number of star sensors were increased from two to three to improve coverage and robustness in onboard attitude determination and to obtain a wider field of view sun sensor. The fault detection, isolation, and reconfiguration (FDIR) system was carefully examined and reconfigured. Together with a planned increase of ground support stations, the survivability of the spacecraft is significantly improved.

A 6U CubeSat “OMOTENASHI” will be the world's smallest moon lander which is launched by NASA SLS Artemis-1. Because of its severe mass and size limitation, it will adopt semi-hard landing scheme. That is, OMOTENASHI is decelerated from orbital velocity to less than 50 m/s by a small solid rocket motor and shock absorption mechanism has been developed to withstand the high-speed impact. Ultra small communication system (X-band and P-band) is also developed. It observes radiation environment of Earth and moon region with portable dosimeters. This paper shows the mission outline, the design, and the development results of OMOTENASHI.

The balloon-borne very long baseline interferometry (VLBI) experiment is a technical feasibility study for performing radio interferometry in the stratosphere. The flight model has been developed. A balloon-borne VLBI station will be launched to establish interferometric fringes with ground-based VLBI stations distributed over the Japanese islands at an observing frequency of approximately 20 GHz as the first step. This paper describes the system design and development of a series of observing instruments and bus systems. In addition to the advantages of avoiding the atmospheric effects of absorption and fluctuation in high frequency radio observation, the mobility of a station can improve the sampling coverage ("uv-coverage") by increasing the number of baselines by the number of ground-based counterparts for each observation day. This benefit cannot be obtained with conventional arrays that solely comprise ground-based stations. The balloon-borne VLBI can contribute to a future progress of research fields such as black holes by direct imaging. (C) 2018 Published by Elsevier Ltd on behalf of COSPAR.

© The Authors. The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month.

<p>An Extensible Optical Bench (EOB) for a X-ray satellite (ASTRO-H) had a length of 6.4m in extended configuration. Although the same type of extensible mast was used in Space Radio Telescope (Halca) in 1997, the tip mass was quite different in the case of ASTRO-H. Due to the tip mass of 150 kg, the natural frequency of EOB was less than 1Hz in the extended configuration. ASTRO-H was launched on Feb. 17, 2016, and the EOB was extended on Feb. 28, 2016, successfully. However, because the vibration of EOB occurred during the extension, the extension operation was carried out over four passes intermittently. When the amplitude of induced vibration excessed the predefined threshold, we stopped the extension, then stayed until the vibration was damped. In this paper, the induced vibration during extension and its mechanism are reported. Through simulations, it is confirmed that one of the major causes of the vibration is a periodic change of gap between mast and canister at the root of EOB.</p>

The Hitomi (ASTRO-H) mission is the sixth Japanese X-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E > 2 keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft X-rays to gamma-rays. After a successful launch on 2016 February 17, the spacecraft lost its function on 2016 March 26, but the commissioning phase for about a month provided valuable information on the on-board instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month.

In this paper is presented a microgravity experiment system utilizing a high altitude balloon. The feature is a double shell structure of a vehicle that is dropped off from the balloon and a microgravity experiment section that is attached to the inside of the vehicle with a liner slider. Control with cold gas jet thrusters of relative position of the experiment section to the vehicle and attitude of the vehicle maintains fine microgravity environment. The design strategy of the vehicle is explained, mainly referring to differences from the authors' previous design. The result of the flight experiment is also shown to evaluate the characteristics of the presented system.

In this paper, direction control of balloon gondola with only untwisting motor is proposed. Typically a reaction wheel and another actuator for unloading the reaction wheel are in use to control the attitude (or direction) of the gondola. Although this method can get high accuracy control performance, two actuators spend many resources of the gondola. The proposed method uses only untwisting motor installed above the gondola to rotate. This method can not realize such high accuracy control performance but realize direction control with the most simple configuration. The proposed method is applied to prototype GAPS (General Anti-Particle Spectrometer) balloon experiment in 2012. This paper shows control design for this experiment and the results of the proposed method.

The General AntiParticle Spectrometer experiment (GAPS) is foreseen to carry out a dark matter search using low-energy cosmic ray antideuterons at stratospheric altitudes with a novel detection approach. A prototype flight from Taiki, Japan was carried out in June 2012 to prove the performance of the GAPS instrument subsystems (Lithium-drifted Silicon tracker and time-of-flight) and the thermal cooling concept as well as to measure background levels. The flight was a success and the stable flight operation of the GAPS detector concept was proven. During the flight about 10(6) charged particle triggers were recorded, extensive X-ray calibrations of the individual tracker modules were performed by using an onboard X-ray tube, and the background level of atmospheric and cosmic X-rays was measured. The behavior of the tracker performance as a function of temperature was investigated. The tracks of charged particle events were reconstructed and used to study the tracking resolution, the detection efficiency of the dacker, and coherent X-ray backgrounds. A timing calibration of the time-of-flight subsystem was performed to measure the particle velocity. The flux as a function of flight altitude and as a function of velocity was extracted taking into account systematic instrumental effects. The developed analysis techniques will form the basis for future flights. (C) 2013 Elsevier B.V. All rights reserved.

The General Antiparticle Spectrometer (GAPS) experiment is a novel approach for the detection of cosmic ray antiparticles. A prototype GAPS (pGAPS) experiment was successfully flown on a high-altitude balloon in June of 2012. The goals of the pGAPS experiment were: to test the operation of lithium drifted silicon (Si(Li)) detectors at balloon altitudes, to validate the thermal model and cooling concept needed for engineering of a full-size GAPS instrument, and to characterize cosmic ray and X-ray backgrounds. The instrument was launched from the Japan Aerospace Exploration Agency's (JAXA) Taiki Aerospace Research Field in Hokkaido, Japan. The flight lasted a total of 6 h, with over 3 h at float altitude ( similar to 33 km). Over one million cosmic ray triggers were recorded and all flight goals were met or exceeded. (C) 2013 Elsevier B.V. All rights reserved.

The General Anti-Particle Spectrometer (GAPS) project is being carried out to search for primary cosmic-ray antiparticles especially for antideuterons produced by cold dark matter. GAPS plans to realize the science observation by Antarctic long duration balloon flights in the late 2010s. In preparation for the Antarctic science flights, an engineering balloon flight using a prototype of the GAPS instrument, "pGAPS", was successfully carried out in June 2012 in Japan to verify the basic performance of each GAPS subsystem. The outline of the pGAPS flight campaign is briefly reported.

The General Antiparticle Spectrometer (GAPS) experiment is an indirect dark matter search that aims to detect low-energy antideuterons resulting from dark matter annihilations in the galactic halo. This signature, which has negligible conventional astrophysical background, is predicted by many models of both supersymmetry and extra-dimensional theories. Until now, an optimized low-energy search experiment has been lacking. In this contribution, the scientific and experimental case for GAPS will be reviewed, and its complementarity with existing indirect and direct search experiments will be discussed. We will describe the design of GAPS, which consists of a time-of-flight system and layers of Si(Li) detectors in a tracking geometry designed specifically for low-energy antideuteron detection. The results of our successful prototype balloon flight (pGAPS), which flew from Japan in June 2012 and met 100% of its mission goals, as well as the path forward to a science flight of GAPS from Antarctica, will be presented.

The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the highenergy universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV. These instruments include a high-resolution, high-Throughput spectrometer sensitive over 0.3-12 keV with high spectral resolution of ?E 5 7 eV, enabled by a micro-calorimeter array located in the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5-80 keV, located in the focal plane of multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12 keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the 40-600 keV band. The simultaneous broad bandpass, coupled with high spectral resolution, will enable the pursuit of a wide variety of important science themes. © 2012 SPIE.

The Japan Aerospace Exploration Agency (JAXA) is developing a system to provide a high-quality, long duration microgravity environment using a capsule that can be released from a high-altitude balloon. Since 1981, an average of 100 million dollars is spent every year on microgravity research by space agencies in the United States, Europe, and Japan. There are many ways to achieve microgravity conditions such as (in order of experiment duration) drop towers, parabolic flights, balloon drops, sounding rockets, the Space Shuttle, recoverable satellites, and the International Space Station. Nowadays, GNSS is used for absolute and relative positioning of aircraft and spacecraft as well as determination of their attitude. What these applications have in common is that, in general, the orientation of the platform is changing relatively slowly. JAXA is developing the Attitude Determination Package for a future version of the BOV, which contains Sun Aspect Sensors (SAS), the Geomagnetic Aspect Sensor (GAS), an inclinometer, and a gyroscope.

A radio astronomical observatory satellite ``ASTRO-G'', which will be launched in 2012, has two characteristics: flexible appendages and high-speed and high-precision attitude maneuvering. Because of these two antithetical features, attitude control system (ACS) of ASTRO-G becomes quite challenging in comparison with those of past satellites. For such a satellite, feedforward control which is robust to model identification error is considered to be important. Nil-Mode-Exciting (NME) profiler is one of references for anti-vibration, which is designed to excite no flexible modes, and thus its robustness is considered to be of most significant. NME profiler, however, is relatively slow reference because of negligible high frequency component. In this paper, we propose Modified NME profiler which is relatively fast reference designed by convolution of NME profiler and Input Shaper. Some anti-vibration experiments are carried out to show the effectiveness of the proposed reference.

JAXA has been developing a system to provide a long duration, good quality microgravity environment based on a capsule, named the Balloon-based Operation Vehicle, that can be released from a balloon. In this paper we will describe the Balloon-based operation vehicle itself and the experiments using GPS performed - in cooperation with Delft University of Technology - on the gondola of the balloon in 2008 (single baseline estimation) and 2009 (full attitude determination and relative positioning). The attitude calculated using raw observations from a GPS receiver during the 2009 experiment is compared with Sun Aspect Sensors' and Geomagnetic Aspect Sensor's results and moreover with the attitude as provided by the receiver itself.

After the success of remotely-sensed global observation by SELENE orbiter, Japan has been focusing on the in-situ exploration of the Moon. To know more about the Moon, numerous missions have to be launched to the Moon for surveying different interesting places. Naturally the cost of single mission must be reduced. Japan has been considering a landing mission for about ten years as a next mission to the Moon. This has a few tons of weight and costs a few million euros including the launch vehicle because it also features the future manned mission. Obviously it is not suitable for scientific in-situ exploration, which must be conducted repeatedly. The authors have been studying a small lander on the Moon or the planets in order to enable the multiple in-situ explorations cheaply. With the technologies developed in our studies, the mission named SLIM (Smart Lander for Investigating Moon) has been proposed to demonstrate an autonomous, accurate and soft landing on the specified place of the Moon. SLIM is also helpful to increase the success probability of the nation-led flagship landing mission when it is conducted as a precursor. This paper describes the proposed SLIM mission.

To provide long duration and good quality of micro-gravity environment with moderate cost, we proposed and have been developed an experiment system that is released from a high altitude balloon. The experiment system has a double-shell drag-free structure and it is controlled not to collide with the inner shell to realize good quality of micro-gravity environment. This paper shows the configuration of the experiment system and summarizes its five-year development including three flight test results. The fist stage of the development was successfully completed this year. The next step is micro-gravity fall with engine for longer duration of experiment. Another direction of the development is real operation of the system for micro-gravity scientists. Those future plans are also described.

This paper discusses on control law for Balloon Based Micro-Gravity Experimental Vehicle. The vehicle is carried up to an altitude of 40km by a balloon and released. During the free fall, micro-gravity environment is provided in a spherical laboratory floating in the vehicle. Gas jet thrusters control the vehicle to keep the clearance between the laboratory and the inner wall of vehicle. This paper proposes new thruster distribution law, which reduces the fuel consumption without increasing of attitude error. Flight experiment has been carried out successfully in May, 2007. This paper also reports the results.

Reported in this paper is the initial phase operation of the attitude and orbit control system (AOCS) of Japanese satellite "AKARI". AKARI is the first Japanese satellite dedicated to the infrared astronomy. AKARI was successfully launched by M-V rocket from Kagoshima Space Center on February 22, 2006. Just after the launch, AKARI faced to a serious problem. It was found that something interferes with the fields of view of two (out of two) sun sensors. The two sensors were out of use in the subsequent AOCS operation. Fortunately, by using two star trackers and gyros, the attitude accuracy required for the scientific observation can be achieved without the sun sensors. However, as other many satellites, the sun sensors were to play important roles in AKARI's AOCS operation. Firstly, they were to be used for sun acquisition at the very initial phase. The anomaly prevented us from carrying out the pre-planned sequence. However, the crisis was overcome with the appropriate ground support operation. Secondly, for the observation in far infrared wavelength, the telescope and the scientific instruments of AKARI are stored in the cryostat and cooled by liquid Helium. To prevent the sun light inflow to the telescope, the attitude of AKARI against the sun is strictly constrained after the scientific observation starts. The sun sensors were to be used to watch the sun direction to keep the appropriate attitude against the sun even when AKARI falls into the safe mode. To save the cryostat from the sun light in the absence of the sun sensors, AOCS architecture was reconfigured so that the equivalent function is achieved by the remaining sensors. The experiences in this recovery operation are mainly reported in this paper. In addition, unexpected continuous orbit rising was observed in the operation. The cause of the phenomenon and the investigation process are also reported.

Reported in this paper is the initial phase operation of the attitude and orbit control system (AOCS) of Japanese satellite "AKARI". AKARI is the first Japanese satellite dedicated to the infrared astronomy. AKARI was successfully launched by M-V rocket from Kagoshima Space Center on February 22, 2006. Just after the launch, AKARI faced to a serious problem. It was found that something interferes with the fields of view of two (out of two) sun sensors. The two sensors were out of use in the subsequent AOCS operation. Fortunately, by using two star trackers and gyros, the attitude accuracy required for the scientific observation can be achieved without the sun sensors. However, as other many satellites, the sun sensors were to play important roles in AKARI's AOCS operation. Firstly, they were to be used for sun acquisition at the very initial phase. The anomaly prevented us from carrying out the pre-planned sequence. However, the crisis was overcome with the appropriate ground support operation. Secondly, for the observation in far infrared wavelength, the telescope. and the scientific instruments of AKARI are stored in the cryostat and cooled by liquid Helium. To prevent the sun light inflow to the telescope, the attitude of AKARI against the sun is strictly constrained after the scientific observation starts. The sun sensors were to be used to watch the sun direction to keep the appropriate attitude against the sun even when AKARI falls into the safe mode. To save the cryostat from the sun light in the absence of the sun sensors, AOCS architecture was reconfigured so that the equivalent function is achieved by the remaining sensors. The experiences in this recovery operation are mainly reported in this paper. In addition, unexpected continuous orbit rising was observed in the operation. The cause of the phenomenon and the investigation process are also reported.

This paper proposes a new micro gravity experimental system called BOV (Balloon-based Operation Vehicle). BOV uses a free-fall capsule with double-shell structure to prevent influence of aerodynamic disturbance. Additionally, BOV is raised to 40km by a high altitude balloon to extend micro gravity duration to 30(or possibly 60) seconds. Thus we realize a medium duration micro gravity system with good micro gravity environment. In this system, the most characteristic point is double-shell structure. The inner shell can fall freely since the outer shell measures the relative position with laser displacement sensors and is controlled by gas-jet thrusters not to collide the inner shell. Therefore the inner shell can be uninfluenced of the dynamic pressure and other aerodynamic disturbances ideally. The BOVs project has run since 2004. The first flight to check the whole system was accomplished in 2006. The aim of this flight was test of a high altitude balloon, communication and data handling system, control system, onboard electronics and operation. The second flight expected to achieve 30 seconds micro gravity was also accomplished on May in 2007. This paper presents the development of BOV's control system and shows the experimental results of micro gravity and consideration for effectiveness of the proposed system. Copyright 2007 by the IAF or the IAA. All rights reserved.

Hayabusa spacecraft performed the final descents and touchdowns twice in November 2005. In final descent phase, terrain alignment maneuvers were accomplished to control both altitude and attitude with respect to the surface by using four beams Laser Range Finder onboard. Then Hayabusa spacecraft made dynamic touchdowns the surface of the asteroid by the sampler system to collect samples automatically. This paper presents the terrain alignment maneuver and touchdown scheme. This paper also describes the novel sample horn system and touchdown dynamics. Touchdown tests on the ground are presented. Then the flight results on touchdown dynamics are shown and discussed. Copyright © 2006 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.

Balloon-based Operation Vehicle (BOV) is currently developed at JAXA for the realization of microgravity environment. As for this research, second experiment of 2006 and third experiment of 2007 are already planned. As a member of the control and electric system group, we estimate a method to detect the relative position of an integumentary covering as an inner shell of an experimental device with laser sensors. In this paper is explained a summary of a microgravity experimental device and shown it about an experiment performed in May, 2006.