Satellite Design Methodology To Suppress Time-varying Residual Magnet Effects on Attitude For Nano-Satellites

An astrometry satellite for Infrared Exploration “Nano-JASMINE” is being developed by intelligent Space System Laboratory (ISSL) University of Tokyo in cooperation with National Astronomical Observatory of Japan (NAOJ). The main objective of this mission is to measure 3-D positions of stars in our galaxy. In order to get the astrometry data accurately, the attitude should be stabilized to less than 740mas/8.8s (4×10−7 rad/s) during observations. In nano-satellites, magnetic disturbances are dominant attitude disturbances unlike large satellites. Magnetic disturbances are caused by the interaction between the Residual Magnetic Moment (RMM) of the satellite and the geo-magnetic field. To decrease magnetic disturbances accurately, we must cope with not only constant components of the RMM but also time-varying components of the RMM, and this problem is not needed to consider in large-satellites. Therefore, there are few established design methods, evaluating methods and measuring techniques about magnetism. In this paper, we introduce the new approach to the magnetic management for nano-satellites which require high-accuracy attitude stability.