A new method for the determination of the inertia tensor of spinning bodies

A new method for the determination of the mass inertia tensor of spinning bodies is presented. By modifying the inertia tensor of a spinning rigid body by known amounts at least twice and calculating rotation matrices and rate vectors before and after each inertia change, the original inertia tensor can be predicted. Accuracy of this method is sensitive to the accuracy of the calculation of rotation matrixes and rate vector accuracy. This method is intended for use by spacecraft while on orbit.; Hardware was built and used to verify the theory on the ground. However, the hardware was found to not conserve angular momentum sufficiently (due to aero-torques) to allow verification of theory. Computer simulations agree with theoretical prediction. Expected accuracies as a function of the quality of angular information are presented. Description of the mechanisms used is also presented. Several important design parameters for spacecraft application are discussed.