Attitude Vibration Caused by a Stick-Slip Motion for Flexible Solar Array of Advanced Earth Observation Satellite

Abstract

The Advanced Earth Observation Satellite (ADEOS), a remote sensing satellite, was developed by the National Space Development Agency of Japan and launched in 1996. ADEOS had a large flexible solar array, which was made of a membrane-like structure of 23 m in length. During the checkout and subsequent phases of in-orbit operations, it was discovered that the attitude control system was experiencing internal disturbances that had not been anticipated. An intensive investigation based on the down-linked flight data revealed that mechanical vibrations was caused by a stick-slip motion at the tension control mechanism (TCM) of the solar array. The scope of this paper is to present an analytical approach to the stick-slip of the TCM by means of spacecraft attitude responses. The mathematical model utilized assumes that the spacecraft was composed of a main rigid body and flexible appendages, which consist of a number of rigid plates connected by torsional hinges. Key parameters of the hinges are determined by applying the equations of vibration of a uniform cantilever beam with tangible physical parameters. This mathematical model has been evaluated using the ADEOS flight data and ground-based test data. It is concluded that the technical approach and mathematical model utilized have correctly represented actual spacecraft motions.