Apparatus and method for identifying an inertial matrix of a spacecraft

To identify an inertial matrix (12) of a spacecraft (2), components of both an angular velocity vector of the spacecraft (2) over at least a time horizon and an external torque vector of external torques acting on the spacecraft (2) during the time horizon , certainly. A convex problem that has values calculated from the particular components of the angular velocity vector and the particular components of the outer torque vector as input data is defined and solved numerically to identify the inertial matrix. The values computed from the particular components of the angular velocity vector consist of differences between equal components of the angular velocity vector at the beginning and end of the time horizon and integrating products of equal and different components of the angular velocity vector over the time horizon.