Development of the Attitude Control System for Tohoku University SPRITE-SAT Using a New-Model Deployable Mast

Paper number

IAC-08.C1.8.14

Author

Dr. Yuji Sakamoto, Tohoku University, Japan

Coauthor

Ms. Eriko Ujiie, Tohoku University, Japan

Coauthor

Prof. Kazuya Yoshida, Tohoku University, Japan

Coauthor

Dr. Yukihiro Takahashi, Tohoku University, Japan

Coauthor

Dr. Takeshi Sakanoi, Tohoku University, Japan

Coauthor

Mr. Satoshi Kondo, Tohoku University, Japan

Coauthor

Mr. Kei Takiuchi, Tohoku University, Japan

Coauthor

Mr. Yasuhiro Nakazato, Tohoku University, Japan

Coauthor

Mr. Tomoki Sawakami, Tohoku University, Japan

Year

2008

Abstract

The 40-kg microsatellite SPRITE-SAT is being developed by Tohoku University, which is launched by Japanese rocket H-IIA in the autumn of 2008. The satellite observes sprite, which is one of lightning-induced phenomena in the upper atmosphere, at the 660-km circular polar orbit. In this paper, the development of attitude control system using a new-model deployable mast is reported as well as the outline of missions and system.

The sprite was discovered in 1989, which size is about 50-km height and width. SPRITE-SAT has three cameras which observe lightning and sprite simultaneously. The formation mechanism will be solved from the combination of time and position measurements. Especially, the horizontal structure could not be observed by conventional ground observations. The results by SPRITE-SAT are expected to be rapid progress in science research fields.

The one of features in the system design of SPRITE-SAT is the attitude control subsystem by gravity-gradient stability using a deployable mast and magnetic torquers. The mission instruments are installed on the bottom panel, which one must point to the earth direction. The sensors for attitude determination and control are sun sensors and geomagnetic meters. Also, the position is determined by an on-board GPS receiver. The deployable mast with a 1-m mast and a 3-kg tip mass is newly developed. In the mast part, BeCu spring is used, in which a tape of BeCu material are hardened to spiral shape and the structure has a moderate stiffness. This spring has been proved in space as an antenna mast in a sounding rocket mission. In this paper, the design of mechanical structure of mast subsystem and the some test results are reported. In addition, it is verified that the valid gravity-gradient torque can be generated to achieve the earth pointing by the numerical simulation of attitude control.

Abstract document

IAC-08.C1.8.14.pdf

Manuscript document

IAC-08.C1.8.14.pdf (🔒 authorized access only).

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