Aerodynamic characterization of space debris in the VKI Longshot hypersonic tunnel using a free-flight measurement technique

Hypersonic experiments are performed in the VKI Longshot wind tunnel on hemispherical and annular geometries representative of space debris, aiming at determining their lift, drag and pitching moment coefficients. A free-flight technique is used for this purpose where the model is automatically released in the hypersonic flow and safely recovered by the end of the experiment. A schlieren flow visualization technique coupled with a high-speed camera follows the motion of the object as it is exposed to the high-velocity flow. The instantaneous attitude of the free-flying model and its trajectory are determined from image analysis techniques. Correction terms are included to account for the gravity and for the relative motion of the object within the flow. Experimental results are compared with both numerics and theory.