Optimizing Inertial Reaction Wheels for Spacecraft Slewing and Attitude Control

This paper deals primarily with a technique for designing and optimizing a slewing (re-orientation) inertia wheel. The approach, although patterned around NASA´s Orbiting Astronomical Observatory, is general and can be tailored to meet the requirements of most spacecraft utilizing inertia wheels for changing their orientation. A method for slewing the spacecraft is briefly discussed and it is shown how the parameters required to design the inertia wheel affect the final design. The interdependence of other spacecraft subsystems on the optimum inertia wheel design is stressed. Starting with the expression for the theoretical speed-torque curve of the motor, a set of equations are developed for the design optimization of the parameters for an open-loop inertia wheel system. It is the goal of the optimizing technique presented to determine the optimum relationship between weight and power consumption.