Methods for using satellite state vector prediction to provide three-axis satellite attitude control

Abstract

Satellite attitude control methods for use during orbit raising operations to follow a predefined thrust trajectory that meets geometric constraints imposed by sensor and/or telemetry and control antenna fields of view while optimizing the sun angle on the solar array. The method uses low thrust electric propulsion for geosynchronous satellite orbit raising from a transfer orbit to the final geosynchronous orbit. In implementing the methods, a predefined thrust trajectory is generated that is designed to raise a satellite from a transfer orbit to a geosynchronous orbit. A direction-cosines matrix, or quaternion, is generated that aligns a thrust vector defined in the satellite body frame with the predefined thrust trajectory and rotates the satellite body about that vector. Attitude control is performed in accordance with the direction-cosines matrix to align the thrust vector defined in the satellite body frame with the predefined thrust trajectory and rotate the satellite body about that vector to optimize the sun angle on the solar array.