The RW270 is a ball-bearing reaction wheel system for exerting inertia within the attitude control system of a satellite. It includes a brushless DC motor, reaction wheel body, base, welding ring, bearing components and control circuit board. The reaction wheel receives commands from the on-board computer (OBC) which controls the brushless DC motor through the control circuit. The DC motor drives the reaction wheel body rotating as instructed by the OBC. By utilizing angular momentum and reaction torque generated by wheel rotation and acceleration/deceleration separately, the satellite attitude can be adjusted and controlled.