Patent ID: 6012000
Filing Date: 2000-01-04
Classification: B64G

Abstract:
A control system for maintaining the attitude of a satellite in alignment with its mission attitude comprising:a ground station control computer including means to upload satellite reference position and mission attitude data to a satellite onboard computer;a star sensor array to instantaneously sense position data of certain stars relative to the position of the satellite;an onboard satellite control computer including means to receive and store said satellite reference position and attitude data from the ground station computer, said onboard computer further including:means to store reference position modeling algorithms;means to process the sensed star position data from the star sensor array and to calculate the satellite attitude based on a predetermined reference;means to estimate the current satellite reference position based on said uploaded reference position data and said reference position modeling algorithms;means to convert the sensed satellite attitude to the current estimated reference position;means to compare the converted attitude to the mission attitude and generate an attitude adjustment signal relative thereto; andattitude actuating means to adjust the attitude of the satellite in response to the attitude adjustment signal.