The Muir Corporation Mustered Soldiery or MCMS serves as the ground defense of the various planets and stations under the control of the Muir Corporation and the Muir Commonwealth. They are also present in any ground offensive campaign conducted by the Muir. The members of the MCMS are commonly broken into two branches, the Regulars and the SpecOps. Only recently, the SpecOps have been made a separate branch. As a rule, all able bodied men and women are required to perform two years of service in the MCMS, as long as they pass the grueling physical and psychological tests. This compulsory service usually takes place during the person's early twenties.