Project/Area Number |
06804025
|
Research Category |
Grant-in-Aid for General Scientific Research (C)
|
Allocation Type | Single-year Grants |
Research Field |
Space and upper atmospheric physics
|
Research Institution | INSTITUTE OF SPACE AND ASTRONAUTICAL SCIENCE |
Principal Investigator |
YAMAMOTO Tatsundo ISAS Assoc.Prof., 太陽系プラズマ研究系, 助教授 (90182633)
|
Co-Investigator(Kenkyū-buntansha) |
TSURUDA Koichiro ISAS Prof., 惑星系研究系, 教授 (10013682)
HAYAKAWA Hajime ISAS Assoc.Prof., 太陽系プラズマ研究系, 助教授 (90167594)
|
Project Period (FY) |
1994 – 1995
|
Project Status |
Completed (Fiscal Year 1995)
|
Budget Amount *help |
¥2,300,000 (Direct Cost: ¥2,300,000)
Fiscal Year 1995: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1994: ¥700,000 (Direct Cost: ¥700,000)
|
Keywords | Planetary Exploration / Magnetic Field Measurements |
Research Abstract |
Through discussions on possible scientific objectives for magnetic field measurements at future planetary missions, we have reached a conclusion that magnetic field measurements are essential regardless particular scientific objectives in each mission. The required accuracy will be 0.1 nT.With this specification, we have manufactured a test module by using hybrid-ICs that was previously developed. We have found that a magnetometer system smaller than 1 kg is feasible. We carried out a calibration test at a ground facility and gathered data for evaluations on sensitivity, alignment and offset stability. We also studied the stability of magnetometer systems by using in-flight data from AKEBONO and GEOTAIL spacecraft. We have confirmed a scheme for sensitivity, alignment, and offset determination at a ground calibration test by using a test module that satisfies the scientific requirements. However, the offset drift due to temperature changes appears to be so large that we cannot neglect it at small-field measurements. The same results are also found in AKEBONO and GEOTAIL magnetic field measurements. Since these spacecraft are spin-stabilized, we can easily estimate offset and alignment by using in-flight data. In future missions, we expect 3-axis stabilized spacecraft and landers, where we will find a difficulty in a evaluation of offset and alignment by using in-flight data. Estimation methods remain for further studies. In this study, we have discussed autonomous control systems and eject systems for a lander use. These systems depend on an expected lifetime of mission and communication ranges. We have to discuss them from the viewpoint of specifications of each mission.
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