To measure the polarization of gamma-ray bursts in X-ray energy band, we have developed a 50 kg microsatellite named "TSUBAME". The satellite has a compact and high-sensitive hard X-ray polarimeter employing newly-developed shock resistant multi-anode photomultipliers and Si avalanche photodiodes. Thanks to the ultra low-noise detectors and signal processors, the polarimeter can cover a wide energy range of 30−200 keV even at 25 • C with a high modulation factor of 62 %. TSUBAME is in the phase of final functional tests waiting for shipping to Baikonur and will be launched into a sun-synchronous orbit at an altitude of 700 km in late 2014. In this paper, the pre-flight performance of the gamma-ray detector system and the satellite bus system are presented.

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h1雌 s paper， a method for automatic operation ofsatellites using rnultiple ground stations is proposed ． i1 the forrner part of 血 is paper ， a new ground station system which op 血 ゴzes the use ofmu 重 吐ple groし md stations ， and central so 吐 ware called " Scheduler " and " Sequeneer " which is subs 丗 ute ofoperator is proposed ， The ' 已 Schoduler " schedUles operation taskS and control the whole operation sequence autOmatically ． The ' 」 Sequencer " executes eperation taskS such as seriding of antenna angle and radie 丘equency to remote ground station ， 1． 序 論

In this paper, we propose a novel singularity avoidance/passage logic based on inverse kinematics for steering a variable-speed double-gimbal control moment gyro (VSDGCMG). Two solutions generating the command torque are obtained using the inverse kinematics for a VSDGCMG system. The proposed method basically selects the solution close to the current wheel momentum and gimbal angles. A transition to another solution is conducted to reduce the attitude error in the vicinity of the singular state based on an evaluation function that corresponds to the approximate torque error and explicitly includes gimbal rate limitations. Its function results in a decision with small attitude error when compared with a previous method that uses just an approximate gimbal angle without the gimbal-rate limitation. Furthermore, the proposed method generates more precise torque closer to the reference torque than the previous method when avoiding the singular state. The effectiveness of the method is demonstrated through numerical simulations.

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