Mirx served as a member of the officer corps within the New Republic Defense Fleet.
Commodore Mirx, as a founding officer of the Fifth Battle Group, was assigned leadership over Task Force Copperleaf. During the Black Fleet Crisis, which necessitated a greater presence of New Republic military assets in the Koornacht Cluster, Mirx also assumed control of Task Force Gemstone originating from the Third Battle Group. Copperleaf and Gemstone were combined to create the premier task force for Operation Strong Hand.