(JP10288238-A)      The rotary damper comprises a first member coupled to an input shaft with a second member rotatably supported about the input shaft, the first member is rotatable relative to the second member. An electro-rheological magnetic fluid coacts with the first and second members, and a means is provided for generating a magnetic field across the electro-rheological magnetic fluid. A shear resistance characteristic of the fluid is changed to control relative rotational movement between the first and second members.    USE -   An electro-rheological magnetic (ERM) fluid-based damper for controlling the deployment and operation of spacecraft appendages (claimed), e.g. solar array panels, antennas, optical platforms.    ADVANTAGE -   The ERM directly transforms magnetic energy into mechanical energy without multiple mechanical stages. The dampers have a high power to weight ratio, a fast response time, and a controllable and velocity independent damping rate. Reliable, low cost and simple to manufacture.    (US5921357-A)      The rotary damper comprises a first member coupled to an input shaft with a second member rotatably supported about the input shaft, the first member is rotatable relative to the second member. An electro-rheological magnetic fluid coacts with the first and second members, and a means is provided for generating a magnetic field across the electro-rheological magnetic fluid. A shear resistance characteristic of the fluid is changed to control relative rotational movement between the first and second members.    USE -   An electro-rheological magnetic (ERM) fluid-based damper for controlling the deployment and operation of spacecraft appendages (claimed), e.g. solar array panels, antennas, optical platforms.    ADVANTAGE -   The ERM directly transforms magnetic energy into mechanical energy without multiple mechanical stages. The dampers have a high power to weight ratio, a fast response time, and a controllable and velocity independent damping rate. Reliable, low cost and simple to manufacture.