SOFIA performance improvements through active mass damping

The telescope structure of the Stratospheric Observatory for Infrared Astronomy (SOFIA) was subject to vibration excitation due to aircraft motions and airflow. To contribute to the efforts to meet pointing requirements and improve image stability, an active mass damping system for the primary mirror suspension has been designed and implemented during the early years of observatory operation phase. Various reasons had prevented further development for some time, but we were able to reactivate and operate the damping system for a set of selected missions before the premature decommissioning of the observatory. We present analyses from gathered engineering data and from astronomical observations about the effectiveness of the system during those missions and offer a projection on how future SOFIA campaigns would have benefited.