Safe approach and docking to a non-cooperative, tumbling target satellite is one of the main critical issues in on-orbit servicing missions. Knowledge of the inertia properties of the target spacecraft is a prerequisite for many rendezvous and docking aspects. In this paper we propose a method to estimate the center of mass and moments of inertia using optical sensor data. For that, kinematic equations of motion and the conservation of the angular momentum are employed to estimate the unknown quantities with least squares methods. Observability and limitations are discussed and results gained from computer simulations involving different test cases are presented
