AAS 95-416

A Magnetic Attitude Control System for Sun Pointing Satellites

S. M. Wolfe and K. T. Alfriend, B. S. Leonard, Naval Postgraduate School, Monterey, CA

Abstract

Some low altitude missions require that the satellite be inertially pointing at the sun. In this paper a momentum bias attitude control system designed for high inclination, Earth pointing missions is adapted for spacecraft in sun synchronous orbits in an inertial, sun pointing mode. The control system must a) Capture the spacecraft from an initial arbitrary orientation and possibly tumbling configuration to a sun pointing mode, b) Provide fine attitude control in the Earth pointing mode, and c) Provide pitch control and momentum wheel dumping. This paper presents the control law and the system performance in each of the modes given above.