•Control electronics can significantly impact performance. This is specifically the case for closedloop controlled mechanisms. It is important to test these mechanisms with the real control electronics in order to assess this effect, or to include it in the microvibration model. •Tune the operational parameters, e.g. restrict/tune the speed range. If certain speeds excite structural modes of the mechanism and it is possible to avoid these speeds without impacting the operations, this could be a valid approach to minimize the exported microvibration. •More innovative design solutions, such as magnetic bearings or flexures instead of tribological contacts could be envisaged. Noise source optimization does not necessarily end at the design stage, but can continue during AIT.  Reducing the environmental loads on mechanisms generally reduces the final microvibration  performance. If it is clear which (mechanical) environment has the largest impact on the performance,  local reductions could potentially be negotiated. Alternatively, the mechanism can be protected using  vibration isolation systems. In addition, the selected model philosophy can also have an impact. For  protoflight/protoqual models, the higher qualification mechanical loads can lead to higher exported  microvibration. Choosing a full qualification model (QM) means the flight models will only be exposed to  the lower acceptance-level vibration environment.   Noise source isolation can be an effective approach to attenuate the exported microvibration. It may be  more efficient and cost effective to isolate particular mechanisms than to design a low-noise mechanism.  For certain very demanding requirements, a combination of both may be required [11]. Dedicated  isolation systems can be used to reduce the exported microvibration, but it may even be possible to  design isolation into the mechanism itself. Passive isolation systems based on visco-elastic isolators are  used most often, although other, more performant/complex systems exist as well. Interestingly, isolation  systems can be designed with a dual function to reduce the environmental loads on the mechanism,  thereby protecting the mechanism and improving its performance, as well as reducing the exported  microvibration.  Conclusion  Microvibration can be a design driver for mechanisms. This paper has collected a number of good  practices and lessons learned on how to deal with microvibration when designing a mechanism.  Appropriately understanding the impact of microvibration requirements and taking them into account in  the early stages of a mechanism development can avoid many problems later during the project. A clear  and feasible verification approach needs to be devised at the same time.  Further improvements in this area are key for future missions, both in terms of mechanism design and  verification approaches which avoid unnecessary conservatism.  References  1. Cabon, B., Seabrook, T. and Richardson G.  "TDS-1 In-orbit microvibration experiment." Mechanisms Final Presentation Days , 15-17 June 2016. 2. Ferreira, R. A.  "Reaction Wheel Technology Consolidation Final Report." ESA Contract No. 4000116154/15/NL/PS , 3 November 2017. 3. Richardson G., Aglietti, G., Remedia, M., Seabrook T.  "Methodology for Analysis of Structure-borne Microvibration – Final Presentation." ESA Contract No. 4000101914/0/0/0 , 26 June 2014. 4. Soula, L. " METhodology for Analysis of structure-borne MICro-vibrations (METAMIC)." ESA Contract No.4000101886/10/NL/RA, 18 February 2012. 5. Steier, F., Runte, T.  "MicroMap – Microvibration Management Approach – Final Presentation." Mechanisms Final Presentation Days , 15-17 June 2016. 6. Gupta, Pradeep K. Advanced Dynamics of Rolling Elements .  Berlin: Springer-Verlag, ©1984. NASA/CP—2018-219887 203