Method and apparatus for steering the attitude of a satellite

Apparatus for steering attitude of a satellite, the apparatus comprising:

• a cluster of at least three CMGs for three-axis steering and of at least two CMGs for two-axis steering, the CMGs having respective wheels mounted on gimbals that are mounted on a satellite platform for rotation about different orientation axes by respective gimbal motors;
• means for determining, from starting and desired end conditions in terms of satellite attitude and angular velocity and from allowed time duration for attitude change, a new configuration of orientations of the gimbals in the cluster that is remote from any singular configuration and is such that exchange of angular momentum between the cluster of CMGs and the satellite within said allowed time duration will cause a desired attitude maneuver from said starting conditions to said end conditions to take place;
• and
• means for simultaneously and independently driving the gimbal motors in such a manner as to bring the orientation of each gimbal about the orientation axis thereof into a set orientation corresponding to the new configuration by applying an angular position reference in open loop in an on-board local angular position servo-control of all gimbals.