Improvement of Smart Radiation Device

Paper number

IAC-05-C2.4.07

Author

Mr. Akira Okamoto, NEC Toshiba Space Systems, Ltd., Japan

Coauthor

Mr. Yasuyuki Nakamura, NEC Toshiba Space Systems, Ltd., Japan

Coauthor

Dr. Akira Ohnishi, Japan Aerospace Exploration Agency (JAXA)/ISAS, Japan

Coauthor

Mr. Sumitaka Tachikawa, Japan Aerospace Exploration Agency (JAXA)/ISAS, Japan

Coauthor

Dr. Kazunori Shimazaki, Japan Aerospace Exploration Agency (ISTA/JAXA), Japan

Coauthor

Mr. Kentaro Sakagami, NEC Toshiba Space Systems, Ltd., Japan

Year

2005

Abstract

Controlling radiation heat transfer to deep space is one of the essential means to maintain spacecraft temperature. Authors have developed the Smart Radiation Device (SRD), which easily provides such function without aids of any electrical instruments or mechanical parts. SRD is a thin and light ceramic tile easy to attach on the spacecraft external surfaces like conventional OSR. SRD material undergoes a metal-insulator transition at room temperature and this allows the infrared emissivity of the device to change from low to high as the temperature increase. SRD’s positive temperature variance of emissivity automatically stabilizes spacecraft temperature at near room temperature. SRD is expected to be light, compact and low cost substitution for the conventionally used thermal louvers. It eventually reduces the electrical heater power for thermal control, and decreases the mass and the cost for the thermal control subsystem.
The authors applied SRD on the HAYABUSA spacecraft developed by JAXA for the ambitious asteroid sample return mission.  HAYABUSA was successfully launched in May 2003 and heading for the target asteroid. Her solar load will vary by more than factor 3.8 according to distance to the sun during her mission. The SRD tiles will be put on the radiator of the communication transmitter, which will be intermittently operated during its mission. SRD is expected to minimize its temperature variation and to save the substituting heater power while it is non-operational.
The authors are improving SRD for getting superior performance for much broader satellite applications. We have recently achieved low solar absorptivity as low as 0.2 by depositing multi-layered dielectric coating on its front surface.
This paper will deals with the outline of SRD, qualification status, its potential applications.

Abstract document

IAC-05-C2.4.07.pdf

Manuscript document

IAC-05-C2.4.07.pdf (🔒 authorized access only).

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