| Project/Area Number |
16360426
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Aerospace engineering
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| Research Institution | Kyushu Institute of Technology |
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Principal Investigator |
CHO Mengu Kyushu Institute of Technology, Faculty of Engineering, Professor, 工学部, 教授 (60243333)
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| Co-Investigator(Kenkyū-buntansha) |
OTSUKA Shinya Kyushu Institute of Technology, Faculty of Engineering, Associate Professor, 工学部, 助教授 (60315158)
TOYODA Kazuhiro Laboratory of Spacecraft Environment Interaction Engineering, Associate Professor, 宇宙環境技術研究センター, 助教授 (10361411)
KUNINAKA Hitoshi JAXA, Institute of Space and Astronautical Sciences, Professor, 宇宙科学研究本部, 教授 (60234465)
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| Project Period (FY) |
2004 – 2006
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| Project Status |
Completed (Fiscal Year 2006)
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| Budget Amount *help |
¥15,100,000 (Direct Cost: ¥15,100,000)
Fiscal Year 2006: ¥3,300,000 (Direct Cost: ¥3,300,000)
Fiscal Year 2005: ¥3,600,000 (Direct Cost: ¥3,600,000)
Fiscal Year 2004: ¥8,200,000 (Direct Cost: ¥8,200,000)
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| Keywords | Satellite / Solar Cell / Discharge / Charging / Plasma / Field Emission / 静止軌道 / 高電圧 / 宇宙 |
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| Research Abstract |
Since 1990s, satellite anomalies due to surface charging have increased as bus voltage of many geostationary telecommunication satellites increased to 100V. The surface charging of GEO satellites was once solved in 1980s. The increase of the satellite bus voltage, however, produced new problems. The purpose of this research is to develop affordable mitigation methods of surface charging that can be applicable to a large GEO commercial satellite.
In this research we produced prototypes for the following two methods and tested their effectives in laboratory experiments;
(1) Electron emitter that emits electrons automatically as the satellite potential drops to a negative value and prevent charging of a satellite body.
(2) Lightning rod that discharges itself with much smaller voltage before discharges occur on solar array.
The electron emitter that had triple junction made of carbon conductive adhesive and polymer film exposed to space was effective. Electrons were emitted from the edge of the carbon conductive adhesive and stable emission of nearly 1 hour was observed. If we put 100 pieces of several cm square, we can prevent charging of a large GEO satellite.
The lightning rod that was dummy solar cell with its edge roughened discharged more easily than conventional solar cell by a factor of more than 100. By putting these dummy cells on solar panel, we can reduce the probability on solar cells to less than 1%.
The two mitigation methods developed in this research are capable of complete passive operation. In the near future, we will seek a flight opportunity to demonstrate their effectiveness in space.
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