Development of Electron Emitting Film for Spacecraft Charging Mitigation
- Paper number
IAC-07-C2.6.06
- Author
Dr. Minoru Iwata, Kyushu Institute of Technology, Japan
- Coauthor
Mr. Hideyuki Igawa, Kyushu Institute of Technology, Japan
- Coauthor
Mr. Yuya Sanmaru, Kyushu Institute of Technology, Japan
- Coauthor
Dr. Hirokazu Masui, Kyushu Institute of Technology, Japan
- Coauthor
Prof. Kazuhiro Toyoda, Kyushu Institute of Technology, Japan
- Coauthor
Prof. Mengu Cho, Kyushu Institute of Technology, Japan
- Coauthor
Mr. Tetsuro Sato, Japan
- Coauthor
Dr. Shinji Hatta, MUSCAT Space Engineering, Japan
- Coauthor
Mr. Tatsuhito Fujita, Japan Aerospace Exploration Agency (ISTA/JAXA), Japan
- Coauthor
Mr. Yasumasa Hisada, Japan Aerospace Exploration Agency (JAXA), Japan
- Year
2007
- Abstract
Since the end of the last decade, size of geostationary (GEO) satellites has increased dramatically. Nowadays, power level of 10 kW is very common among commercial GEO telecommunication satellites. For such a high power generation, there is need to increase bus voltage to more than 100V to decrease cable mass and to increase electrical power transmission efficiency. However the risk of discharge on the solar array increases with the bus voltage. The discharge can cause short-circuit and may lead to destruction of the power system, and then entire functions of spacecraft may fail as the power is lost. Such discharges occur due to anomalous surface charging that a part of dielectric surface on a satellite has a different potential from the satellite body potential. Therefore, by making an escape path of stored charge on dielectric surface, we can avoid the discharge on solar array. The purpose of this work is to develop the methods to mitigate surface charging applicable to GEO satellites. In this paper, we present the mitigation strategy of Electron Emitting Film for Spacecraft Charging Mitigation (ELF’S CHARM). The electron emission device emits electrons from the spacecraft structure via field emission. Usually, the potential of spacecraft structure falls to negative when the spacecraft encounters the substorm. The electron emission device prevents the spacecraft potential from falling negative. For the electron emission device, the mitigation performance of surface charging was evaluated in vacuum chamber by using the variation on bias voltage of the coupon panel on which the electron emission device was attached. The pressure in the chamber could be as low as 1×10−4 Pa. We irradiated an electron beam on the surface with an electron gun (Ulvac; RHEED) to simulate the substorm condition. We evaluated the mitigation performance of device and obtained good mitigation performance. The details of experimental results will be presented at the conference.
- Abstract document
- Manuscript document
IAC-07-C2.6.06.pdf (🔒 authorized access only).
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