The Magnetically Clean Reaction Wheel: Results and Performance

Magnetic cleanliness has become an important and design driving requirement for satellites and components on most scientific missions. Main contributors to the disturbing magnetic fields of a satellite are the reaction wheels. Their internal design (electric motors, ferromagnetic parts) and high-speed operation, result in significant electromagnetic stray fields in various frequency ranges. To meet magnetic cleanliness requirements, reaction wheels are often housed in additional shielding on-board the satellite. This results in a significant mass increase and requires more magnetic (shielding) material on-board the satellite. Previous works have described the on-going efforts in the magnetically clean reaction wheel design [1] [2] [3] [4]. This paper summarizes these efforts and describes the results of the magnetically clean reaction wheel project. Magnetic field mitigation techniques have been implemented in the new wheel EQM (Engineering Qualification Model) and the final impact on the magnetic footprint is discussed.