Abstract: A system for accurately controlling the movement of an object through a predetermined non-rectilinear path in a predetermined volume having X, Y and Z axes. The system uses three tracking laser interferometers rigidly positioned relative to the volume and a single retroreflector rigidly coupled to the object to control movement of the object non-rectilinearly through the volume along a predetermined path. Using two more tracking laser interferometers and an additional retroreflector rigidly coupled to the object, the system controls angular orientation of the object about one of the axes. Adding a sixth tracking laser interferometer and a third retroreflector to the object, the system can also control angular orientation about the other two axes. Each tracking laser interferometer comprises an interferometer and a tracking mirror which is pivoted to maintain the interferometer output beam on its associated retroreflector.