Modal Damping Measurement of MOS-1 Solar Array Paddle

Abstract Dynamic test on MARINE OBSERVATION SATELLITE-1 (MOS-1) paddle structure was conducted to measure damping coefficients of lower three modes. The experimentation was carried out by making use of the paddle engineering model in the space chamber at 0.01 Torr. Precautions against the effect of the gravity force, interface damping, suspension cable length and data processing software on the test results are carefully taken so that the data survive severe technical scrutinies. The dynamic characteristics of the solar array drive and power transmission assembly (SADAPTA) in the torsional direction was examined separately in the open room. The experimental results of the damping coefficients are analytically extrapolated to the on-orbit values; 1.1%, 0.4% and 0.45% for 1st, 2nd and 3rd modes respectively.