Space Systems/loral, LLC

George E White

Kam K Chan

Xenophon H Price

Philip Conway Hirschberg

Bruce Brumfield

Methods and apparatus for a spacecraft () orbiting about a celestial body such as the Earth to reacquire operational three-axis orientation with respect to that body. A method embodiment of the invention comprises determining () a set of actual conditions of the spacecraft, comprising a position of the spacecraft () in inertial space as a function of time and a set of angular rotation rates of the spacecraft () with respect to a coordinate frame of the spacecraft (), determining () an actual instantaneous direction of the sun with respect to the coordinate frame, and propagating () an estimated actual sun direction with respect to the coordinate frame as a function of time; determining () a desired sun direction with respect to the coordinate frame as a function of time; rotating () the spacecraft () and adjusting angular rotation rates of the spacecraft () so that an actual angle between the spacecraft () coordinate frame and the sun as a function of time substantially coincides with the desired sun direction with respect to the coordinate frame as a function of time; and, rotating () the spacecraft () around an axis defined by a line between the sun and the spacecraft until () the celestial body is observed by a celestial body sensor of the spacecraft.

Growing community of inventors

San Jose, CA, United States of America

George E White