Managing Reaction Wheel Microvibration on a High Resolution EO Small Spacecraft

The SSTL 300 S1 spacecraft is capable of capturing images with a spatial resolution of 1m. One of the main technical challenges for this mission is to eliminate effects of microvibration on the imagery. Microvibration on the SSTL 300 S1 spacecraft is mainly caused by mechanical noise generated by the reaction wheels. This has been addressed by optimising the reaction wheel's microvibration performance. The optimisation is driven by the modes at which the spacecraft is sensitive to microvibration. Furthermore, a new isolation system has been designed to further reduce the reaction wheel noise levels. Since the isolation system has very low resonant frequencies the wheels need to be locked down to meet the structural requirements during launch. This paper presents the reaction wheel optimisation and the design and test results of the integrated wheel isolation and lockdown system.