GUIDANCE AND NAVIGATION Critical to the flight of any vehicle through interstellar space are the concepts of guidance and navigation. These involve the ability to control spacecraft motions, to determine the locations of specific points in three and four dimensions, and to allow the spacecraft to follow safe paths between those points. The theater of operation for the USS Enterprise takes it through both known and unknown regions of the Milky Way galaxy. While the problems of interstellar navigation have been well-defined for over two hundred years, navigating about this celestial whirlpool, especially at warp velocities, still requires the precise orchestration of computers, sensors, active high-energy deflecting devices, and crew decision-making abilities. Æ