Device and method for determining the attitude of a satellite, and satellite carrying such a device

A device for determining an attitude or an attitude variations of a satellite provided with an attitude control system comprising at least one inertial actuator comprising a rotary element mounted to rotate about an axis of rotation, the rotation of the rotary element being controlled to generate an attitude control torque for the satellite, the device comprising:

• an angular sensor to measure an angle of rotation of the rotary element about its axis of rotation;
• and
• a computation unit to determine the attitude or the attitude variation of the satellite, induced by the rotation of the rotary element, as a function of measurements of the angle of rotation of the rotary element by the angular sensor.

A method for determining an attitude or an attitude variation of a satellite provided with an attitude control system comprising at least one inertial actuator comprising a rotary element mounted to rotate about an axis of rotation, the rotation of the rotary element is controlled to generate an attitude control torque for the satellite, the method comprising the steps of:

• measuring an angle of rotation of the rotary element about its axis of rotation by an angular sensor of said at least one inertial actuator;
• and
• determining the attitude or the attitude variation of the satellite by a computation unit, induced by the rotation of the rotary element, as a function of measurements of the angle of rotation of the rotary element by the angular sensor.