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Steerable antennas are widely used for Satellite communications. A steerable reflector array antenna is designed to meet in-flight reconfigurability requirements for space applications such as minimized interference and production of fixed spot beams on the ground from an LEO/GEO Satellite. Indian communication Spacecraft in the discussion was being realized as an exclusive communication satellite catering to user service requirements in Ku-band. It has four Ku-band offset-shaped steerable reflectors of 0.6 m aperture diameter. Normally any deploying/moving mechanism needs a hold-down mechanism to resist the launch loads. Any type of hold-down mechanism requires a release actuator and such a dedicated hold-down system requires both mechanical and electrical resources which means increased mass and power requirements. Hence, a separate launch hold-down requirement is also eliminated by moving the mechanism to the dead centre position. The steering mechanism consists of an input link and an output link connected by a coupler link. Antenna is connected to the output link. The input link is driven by a motor. The link lengths are selected such that the output link oscillates by a known angle for specified rotation of the input link through kinematic analysis. When the motor is operated, the input link rotates and in turn moves the output link up and down about the main bearing axis thereby steering the antenna with high accuracy. This paper presents the concept and design details of the novel steering mechanism incorporating a four-bar linkage for steering through small angles ranging from 0 ∘ to 5 ∘ and back. Additionally, details of hardware realization, performance evaluation through ground testing and on-orbit performance summary are also provided. [ABSTRACT FROM AUTHOR]