Abstract: A drive is provided that comprises at least one pair of coaxial linear guides configured to counterrotate about a rotational axis and a pair of eccentric masses arranged and constrained for reciprocating movement along the coaxial linear guides. Each eccentric mass reciprocates from a first end to a second end and back again to the first end of its corresponding linear guide in a first period of time that is equal to a second period of time required for the corresponding linear guide to complete a full rotation. This results in a phenomenon by which the eccentric masses are constrained to one hemisphere of the circular sweep of the linear guides, producing an internally derived directional thrust. To steer the drive, one of several different mechanisms are used to differentiate the phases, angular momentums, and or displacement between the linear guides of the linear guide-and-piston subsystems.