Testing of spacecraft attitude and orbit control systems

The testing of Spacecraft Attitude and Orbit Control Subsystems is described from the early design up to in-flight, inclusive. Main topics dealt with are: description of three generic AOCS test classes, model philosophy, standardization, subsystem static test methods, subsystem dynamic test methods, generic test equipment and test facilities....

Experimental and system study of Reaction Wheels. Part I: Measurement and statistical analysis of force and torque irregularities

Torque and force irregularities of running reaction wheels were studied. In this first part of the study report results from noise measurements at constant wheel speeds on various types of current technology European reaction wheels, both with ball- and magnet bearings and with DC or AC drive motor, are presented. The measured noise in radial...

Experimental and system study of Reaction Wheels. Part II: System study on wheel state feedback

The increasing power of on-board processors allows more freedom in the design and operation of reaction wheel control systems. This report discusses several performance and implementation aspects of the operation of wheel systems which have their own internal feedback control system. A model following control concept is found to be superior. The...

In-orbit experiment with an attitude control algorithm for ANS based on modern control principles

The existing fine attitude system of the Astronomical Netherlands Satellite was designed on the basis of conventional digital control techniques. The possibility of a more advanced approach is presented in this report. As an example, an alternative control algorithm for the scan mode has been developed with the use of state estimation and state...