Stephen Jae Koffman

US Patent:

62608053, Jul 17, 2001

Filed:

Dec 29, 1998

Appl. No.:

9/222450

Inventors:

John F. Yocum - Rancho Palos Verdes CA
Patrick A. Cazeau - Ladera Heights CA
Stephen J. Koffman - Redondo Beach CA
Douglas A. Baker - Torrance CA

Assignee:

Hughes Electronics Corporation - El Segundo CA

International Classification:

B64G 124

US Classification:

244164

Abstract:

A method is provided for controlling the attitude of a momentum biased spacecraft about all three mutually orthogonal axes during a thruster firing maneuver without separately sensing angular displacement, angular rate, or angular acceleration about the spacecraft yaw axis. The method includes a transient phase during which a yaw feedforward torque is computed based on the known pitch/yaw coupling due to thruster geometry, and a steady state phase, during which feedback gains are adjusted to estimate yaw attitude based on coupling of a steady state disturbance torque about the roll axis of the spacecraft and a steady state disturbance torque about the yaw axis of the spacecraft.