Abstract: Gyroscope instrumentation for providing stabilization of the direction of a ine-of-sight of more than 45.degree. about one or more axes is described utilizing a two axes optical system. An inner gimbal supports a gyro rotor and a first mirror diagonal with a clearance window to admit light. The gyro rotor keeps the first mirror aligned in a fixed direction relative to an inner gimbal axis. The inner gimbal is supported by an outer gimbal. The outer gimbal has a second mirror mounted on it. The gyro rotor keeps the second mirror aligned with the outer gimbal axis. The net effect is that the optical axis at the input has a fixed orientation in space and the optical axis at the output axis has a fixed orientation relative to a platform on which the system is mounted.

Abstract: An aperture in a hull is sealed by a fiber optic plug system that comprises a coherent array of optical fibers that are fused to form the mechanical and structural equivalent of a thick glass plate. Identical terminal blocks are located on either side of the plug. The blocks comprise a plurality of fiber optic channels supported by a matrix. At the end of each block closest to the plug, channels are arrayed in a tightly packed pattern to reduce the size of the aperture in the hull. The other end of the blocks are expanded to allow each channel to be easily accessed via discrete fiber optic cables.