The invention relates to a gear assembly (10) for use in a space craft for control of a moveable component thereof. The assembly comprises a load gear (11) in engagement with a drive gear (12) and an auxiliary gear (13). The drive gear (12) is coupled to a drive motor (14) so as to drive the load gear (11) in a first rotational direction. The auxiliary gear (13) is coupled to a retardation device (15) that is configured to passively resist the load gear (11) from rotating in the first rotational direction.