Kiyoshi H.,Chubu University |
Yui A.,IHI Corporation |
Ines A.V.M.,Columbia University |
Chinnachodteeranun R.,Listenfield Co. |
And 4 more authors.
Annual SRII Global Conference, SRII | Year: 2014
We are developing an agricultural information service platform called Field Touch. More than 100 farmers in Hokkaido, Japan, are participating on this development and they are utilizing our services for optimizing their daily agricultural practices. Field Touch integrates multi-scale sensor data for field monitoring, provides functionality for recording agricultural practices, then supports farmers in decision making. We are updating Rapid eye satellite images every two weeks, and field sensor data from 25 nodes every 10 minutes. Data from national weather observation network, AMeDAS is also a data source at a daily basis. We use 'cloud Sense' sensor backend service that serves meta-data and data to Field Touch via standard web service, SOS (Sensor Observation Service), which brought us a great flexibility and automation in operating the system. We developed a successive simulation scheme as a part of Field Touch for evaluating the impact of climate variability and agricultural practices. © 2014 IEEE.
Kinoshita K.,Japan Aerospace Exploration Agency |
Arai Y.,Japan Aerospace Exploration Agency |
Inatomi Y.,Japan Aerospace Exploration Agency |
Tsukada T.,Tohoku University |
And 17 more authors.
Journal of Crystal Growth | Year: 2014
An alloy semiconductor Si1-xGex (x~0.5) crystal was grown by the TLZ method in microgravity. Ge concentration was 48.5±1.5 at% for the whole region of 10 mm diameter and 17.2 mm long crystal. Compositional uniformity was established but the average concentration was a little deviated from the expected 50 at%. For further improving compositional uniformity and for obtaining Si0.5Ge0.5 crystals in microgravity, growth conditions were refined based on the measured axial compositional profile. In determining new growth conditions, difference in temperature gradient in a melt, difference in freezing interface curvature, and difference in melt back length of a seed between microgravity and terrestrial growth were taken into consideration. © 2013 Elsevier Ltd. All rights reserved.
Isobe N.,Japan Aerospace Exploration Agency |
Nakagawa T.,Japan Aerospace Exploration Agency |
Okazaki S.,Japan Aerospace Exploration Agency |
Sato Y.,Japan Aerospace Exploration Agency |
And 11 more authors.
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2014
The contamination control for the next-generation space infrared observatory SPICA is presented. The optical performance of instruments on space observatories are often degraded by particulate and/or molecular contamination. Therefore, the contamination control has a potential to produce a significant risk, and it should be investigated in the risk mitigation phase of the SPICA development. The requirements from contamination- sensitive components onborad SPICA, the telescope assembly and focal plane instruments, are summarized. Possible contamination sources inside and outside the SPICA spacecraft were investigated. Based on impact on the SPICA system design, the following contamination sources were extensively studied through simulation and measurement; (1) outgassing from the payload module surrounding the telescope mirror and focal plane instruments, (2) contamination due to the thruster plume, and (3) environmental contamination during the integration, storage and verification phases. Although the outgas from the payload module and the thruster plume were estimated to produce only a negligible influence, the environmental contamination was suggested to affect significantly the telescope and focal plane instruments. Reasonable countermeasures to reduce the environmental contamination were proposed, some of which were confirmed to be actually effective. © 2014 SPIE.
Iwata T.,Japan National Institute of Advanced Industrial Science and Technology |
Matsuzawa T.,Japan National Institute of Advanced Industrial Science and Technology |
Kawauchi T.,Mitsubishi Group |
Fukushima S.,Space Engineering Development Co. |
And 5 more authors.
Institute of Navigation - International Technical Meeting 2011, ITM 2011 | Year: 2011
The First Japanese positioning satellite, MICHIBIKI, Quasi-Zenith Satellite-1, was launched successfully on September 11, 2010 from the Tanegashima Space Center of Japan Aerospace Exploration Agency (JAXA). The first three months after the launch were devoted to initial functional verification tests. The National Institute of Advanced Industrial Science and Technology (AIST) has been developing the remote synchronization system of an onboard crystal oscillator (RESSOX) for the Quasi-Zenith Satellite System (QZSS), and planned initial functional verification tests to be conducted at the Time Management Station (TMS) in Koganei (Tokyo) in November and at the TMS in Onna (Okinawa) in December of 2010. Those TMSs are facilities of the National Institute of Information and Communication Technology (NICT). RESSOX reduces overall cost, satellite power consumption, and onboard weight and volume. Moreover, RESSOX has a longer lifetime than a system with onboard atomic clocks. However, MICHIBIKI carries rubidium atomic clocks and RESSOX will be used in the experiments to examine its potential use in future QZSS. Six basic functional capability tests were planned: (1) measurement of time difference between RESSOX control signal and a space vehicle clock, (2) feed-forward capability of RESSOX Experiment One, (3) feedback capability of RESSOX Experiment One, (4) control performance during communication interruption (CI) of RESSOX Experiment One, (5) capability of RESSOX Experiment Two, and (6) control performance during CI of RESSOX Experiment Two, and (1), (2), (4), (5), and (6) were verified. In Experiment One, the RESSOX control signal that includes information on the standard time is sent from ground stations, and the onboard crystal oscillator of MICHIBIKI is controlled to synchronize the arrival of the RESSOX control signal. This is similar to such time calibration signals as WWV or JJY, but compensates the delay. In Experiment Two, on the basis of the results of a time comparison between the onboard crystal oscillator and the standard time conducted by NICT, the voltage applied to the onboard crystal oscillator is calculated at the ground station and is transmitted to MICHIBlKI to control the crystal oscillator. In the actual operation, 35-minute CI occurs twice a day because of the need to avoid interference with other GEO satellites. Therefore, the control performance during CI should be considered. In this paper, first, Experiments One and Two will be described. Second, the results of actual initial functional verification tests are demonstrated. Finally, issues for real experiments are discussed.
Narukage N.,Japan National Astronomical Observatory |
Sakao T.,Japan Aerospace Exploration Agency |
Kano R.,Japan National Astronomical Observatory |
Hara H.,Japan National Astronomical Observatory |
And 9 more authors.
Solar Physics | Year: 2011
The X-Ray Telescope (XRT) onboard the Hinode satellite is an X-ray imager that observes the solar corona with unprecedentedly high angular resolution (consistent with its 1″ pixel size). XRT has nine X-ray analysis filters with different temperature responses. One of the most significant scientific features of this telescope is its capability of diagnosing coronal temperatures from less than 1 MK to more than 10 MK, which has never been accomplished before. To make full use of this capability, accurate calibration of the coronal temperature response of XRT is indispensable and is presented in this article. The effect of on-orbit contamination is also taken into account in the calibration. On the basis of our calibration results, we review the coronal-temperature-diagnostic capability of XRT. © 2010 Springer Science+Business Media B.V.
Hasegawa J.,Space Engineering Development Co. |
Watanabe H.,Japan Aerospace Exploration Agency |
Ohkawa S.,Japan Aerospace Exploration Agency |
Fujita H.,Space Engineering Development Co. |
Wakayama Y.,Space Engineering Development Co.
Proceedings of the International Astronautical Congress, IAC | Year: 2014
The Japanese Experiment Module-Exposed Facility (JEM-EF) is one of the unique facilities onboard the International Space Station (ISS) and that provides users of wide view for the deep space observation as well as of the earth observation. There are 4 JAXA exposed payloads; Monitor of All-sky X-ray Image (MAXI), Space Environment Data Acquisition equipment-Attached Payload (SEDA-AP), Superconducting Submilimeter-wave Limb-emission Sounder (SMILES), and Multi-mission Consolidated Equipment (MCE). One of the most representative research outcomes is given by MAXI. It has discovered 12 X-ray novae since 2009. The purpose of this manuscript is to introduce how multiple JAXA exposed payloads have been operated securely and efficiently. The JAXA exposed payloads are operated by Exposed Payload Operator Team (ExPO Team) consists of Exposed Payload Operator (ExPO), Operator (OP), and Mission Team (MT). The ExPO is an integrator of these payloads and is responsible for timeline and resource coordination. The OP is a dedicated operator for each payload. The main responsibility of the OP is monitoring telemetry and sending commands. The MT is the scientist or developer who is in charge of each experiment. The ExPO is staffed for 24 hours per day throughout the year. On the other hand, the OP is staffed only when the activity is scheduled. When the activity is not scheduled, the ExPO has to monitor all these exposed payloads alone. In order to operate multiple JAXA exposed payloads securely and efficiently, ExPO Team has kept making all kinds of effort. One of the examples is "Command Script". It is the pre-registered command list that corresponds to the procedure. Once it is executed, all pre-registered commands will be sent sequentially. This Command Script is prepared not only for nominal activities, but also for off-nominal events. It allows ExPO Team to save the payloads quickly and securely even if in off-nominal events. In consequence, ExPO Team succeeded in optimizing operation of the JEM-EF. It has already past 5 years since the beginning of the operation, and ExPO Team has maintained secure and efficient operation so far. This operation system has made major contribution to research outcomes of the payloads. Next JAXA exposed payload, CALorimetric Electron Telescope (CALET), will be launched by H-II Transfer Vehicle-5 (HTV-5). ExPO Team continues to make best effort for more secure and efficient operation for CALET and current JEM-EF payloads.
Nomura N.,Space Engineering Development Co. |
Kudoh F.,Japan Aerospace Exploration Agency |
Asama T.,Japan Aerospace Exploration Agency |
Doi H.,Japan Aerospace Exploration Agency |
And 3 more authors.
13th International Conference on Space Operations, SpaceOps 2014 | Year: 2014
Cross support which includes services of a ground station tracks other agency's spacecraft and provides services of telemetry data reception, command data radiation and tracking data provision, is very useful and valuable for spacecraft operation. Especially, to conduct critical operation during launch and early operation phase, de-orbit operation phase, mission critical operation phase and recovery operation from abnormal status (unexpected attitude, low load mode, etc.), operation time can be held long time by cross support. It is necessary to make compatibility between service provider agency and service user agency for cross support. The compatibility includes RF and data link between a spacecraft and a ground station, data interface compatibility of ground systems, data format and protocol, etc. And operation interface compatibility is also necessary. Our team has been working for operation engineering that means developing operation procedure based on mission requirement, spacecraft and ground system specification, operator's position and etc. In this case we developed operation procedure to conduct cross support operation with external agency, including non-cross support that means use the commercial use of ground stations. To establish operation interface compatibility with another agency for the case that JAXA ground station tracks another agency's satellite, we developed with another agency's spacecraft operation engineer about interface procedures in this paper, we will explain the detail of a way of operation engineering for cross support, the result of cross support operation and evaluate experience and clarify good points and improvable points. Also, we will explain a plan to improve operation engineering for future mission and suggest operation engineering standardization, not only communications and data systems like CCSDS, for cross support and interoperable operation.
Aonuma D.,Space Engineering Development Co. |
Miyamoto H.,Japan Aerospace Exploration Agency |
Nohara I.,Space Engineering Development Co. |
Nomura N.,Space Engineering Development Co.
SpaceOps 2012 Conference | Year: 2012
Satellite LEOP operation requires many operators with different specialties to properly conduct the demanding operations such as satellite control, flight dynamics, mission equipment operations, and other operations. Each of these operators has specialized backgrounds, skills and knowledge. Therefore, some satellite operators may only know a little about the ground system while some ground system operators may only know a little about the satellite system. It is of no doubt that training is necessary to ensure the operators obtain the necessary skills and knowledge for smooth and reliable satellite operation. However, the training of satellite operators tends to pose a dilemma in balancing its necessity with limited budget and time constraints. For LEOP operation training, the operators may number around 400 people, with many of them also responsible for pre-launch preparations, thereby being too busy with those duties to attend the operator training. At JAXA's request, an equally effective and efficient training methodology has been developed and applied by SED (Space Engineering Development Co., Ltd.) over the course of three JAXA satellite projects. The methodology was successful in reducing the cost of training while also improving its quality. Effective planning consisting of web-based self-training and practical training is the major element of this training. At the planning stage, the skill map clarified training items in order to avoid unnecessary training of the operators. As a result, excessive training was removed, successfully reducing the manpower cost. The web-based self-training mitigated the time investment and provided greater flexibility, more effectively training the operators. In the practical training, a satellite simulator was used to simulate virtual TT&C operation. This simulator use also resulted in an increased internalization of the skills required by the operators. In this paper, the methodology of the training, along with its effects and results are introduced and discussed. © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
Nomura N.,Space Engineering Development Co. |
Yonekura K.,Japan Aerospace Exploration Agency |
Watanabe Y.,Space Engineering Development Co. |
Aomunuma D.,Space Engineering Development Co.
SpaceOps 2012 Conference | Year: 2012
The tracking and control of spacecrafts has been conducted by members from different organizations working together. During the critical phase (e.g. Launch and Early Orbit Phase), the operation organization consists of the Mission Management team, Launch Site team, Spacecraft Operations team, Ground Station Operations team and other support teams. The number of members during LEOP is larger than during the nominal operation phase. Therefore, it is very important that all members can share and utilize the necessary information for space operations in real time. For SELENE (SELenological and Engineering Explore, JAXA, L/O: 2007) and IKAROS (Interplanetary Kite-craft Accelerated by Radiation Of the Sun, JAXA, L/O: 2010) operations, SOE Display System and Event Timer System were developed. These systems were used as operations support tools. All teams and operation members were able to utilize and share same information by using these tools. As a result, all the operations were conducted by established procedure with certain timing. And also, the necessary information was provided appropriate timing to JAXA's management team and general public. The systems also reduced the time lag for sharing of information among the teams. The SOE Display System has functions that show the visibility from the ground station, spacecraft status, operation procedure steps, ground operation system configuration and other information. The Event Timer System has functions that show the current time (UTC and JST (Japan Standard Time)), event item, event time, time between the event and the current time, and triggering the alarm sound. To synchronize the event item, the SOE Display System has functions to export the event time. The Event Timer System has functions to import the event item. This paper presents functions and provides examples of the system's utilization in real operation, and modifications planned for the SOE Display System and Event Timer System. © 2012 by the American Institute of Aeronautics and Astronautics, Inc. All rights reserved.
Takayama Y.,Japan National Institute of Information and Communications Technology |
Toyoshima M.,Japan National Institute of Information and Communications Technology |
Kura N.,Space Engineering Development Co.
Radioengineering | Year: 2010
The accessible probability of a low-orbit satellite from ground is estimated by using images taken by a eteorological satellite and by analyzing visible passes of the satellite. The study indicates that the ockage by clouds in satellite-ground laser communications is almost avoidable by properly distributing everal optical ground stations. For the calculation, we use an orbit information of a low-earth orbit atellite, the Optical Inter-orbit Communications Engineering Test Satellite (OICETS), as the counterpart of the optical ground stations. The calculation of the cumulative accessible probability shows the required time to achieve over 99% accessibility between the low orbit satellite and the optical ground stations.