2010 Volume 8 Issue ists27 Pages Tm_49-Tm_53
A simple attitude control system for a balloon experiment has been developed. This system aims to achieve an accuracy of 0.1 deg in azimuth for a small payload with a diameter of 1.5 m and a moment of inertia of 100 kg·m2. It will be first flown with the Polarimetry for High ENErgy X-rays (PHENEX) experiment, which is to observe the polarization of astronomical objects in the hard X-ray energy region. The system is composed of the attitude sensors (sun sensors, geomagnetic aspect sensors, and an optical fiber gyro), read-out modules, CPU, output modules (PC104 based boards), and actuators (a torsion relief motor and a reaction wheel motor with their drivers). In this paper, after introducing these modules, the properties of the sensors and the control system based on the ground will be reviewed.