EVALUATION OF ACTIVE DAMPING PERFORMANCES IN-ORBIT

The efforts dedicated to predicting and overcoming the vibrations of s tructures in space have increased dramatically over the last ten years . Motivating factors behind this increase are optical systems with hig h stability requirements, large antennas, sensitive microgravity paylo ads and compatibility of flexible appendages with attitude control. Pr ediction activities combine analytical model and ground tests to simul ate the behaviour of structures. The requirements on structural dynami c transmissions often lead to specific developments in conception such as frequency decoupling with noise sources in the spacecraft, adding passive or active damping in the structural path, or setting up suspen sion devices. This paper focuses on the active damping involved in a t russ structure which will be tested in the MIR station in 1996 within the frame of the CNES experiment CASTOR. This experiment aims at valid ating the analysis and test procedure for advanced space structure dyn amic prediction, and demonstrating in zero gravity conditions the effi ciency of passive and active damping technologies. After introducing t he context, the paper is organised as follows: objectives of CASTOR de sign and optimisation of active damping system test results flight har dware and test plan conclusion, further activities