Estimation of spaceplane model inertia characteristics

The moments and product of inertia of a NAL spaceplane 5-percent model have been determined experimentally. The method was based on a bifilar pendulum system, and estimation errors were also evaluated. As a result, the moment of inertia Iy and Iz were estimated within the error of about 1 percent but Ix and the product of inertia Ixz had larger errors. The largest cause for these errors is that the moment of inertia of a suspension rig about the x axis is relatively large compared with that of the model.