Solar torque estimation for momentum bias spacecraft1

Abstract

This paper introduces a solar torque estimation algorithm for momentum bias satellites, ultimately benefiting yaw pointing performance and momentum management. A subspace of the solar torque is demonstrated to be unobservable without the use of a rate sensor. By decomposing the solar torque environment into observable and unobservable components, this algorithm may be implemented with or without a rate-sensing gyro. Flight data are presented, sharing recent flight experiences with the algorithm in this paper. This telemetry is derived from several recent, large geosynchronous orbit (GEO) satellites, including one with a 12-meter deployable antenna.