Abstract: A system (30) for adjusting the orientation of a spacecraft adapted for use with a satellite (10). The system (30) includes a first control circuit (32, 38, 40) for canceling any momentum of the spacecraft via a counter-rotating spacecraft bus (16, 18). A second controller (32, 42, 44, 46, 48) orients the spacecraft via the application of internal spacecraft forces. In a specific embodiment, the spacecraft bus (16, 18) serves a dual use as storage section and includes a mass (16) having a moment of inertia on the same order as the moment of inertia of the satellite (10). The satellite (10) includes a bus section (16) and a payload section (14). The mass (16) includes the bus section (16). The first control circuit (32, 38, 40) runs software to selectively spin the mass (16) to cancel the momentum of the satellite (10). The software computes an actuator control signal, via a computer (32), that drives a first actuator (38) that spins the mass (16).

Abstract: The optical sensor (10) has a multiple telescope assembly (12), a rotating periscope assembly (14), an imager optical system (16) and a detector (18). The sensor (10) may be utilized with visible, ultraviolet or infrared wavelength radiation. Each telescope (12) views a particular sector of a scene. The rotating periscope (14) multiplexes the output of each telescope (12) to provide a combined wide field of view of each of the sectors. The system may be used in various types of navigation, pilotage, and monitoring systems.

Abstract: A gimbal vibration isolation system suitable for use with an inertial platform to enable accurate positioning of the platform independently of a presence of vibratory translational movement upon a gimbal housing enclosing the platform employs a frame assembly centrally located within platform for pivoting the platform and for isolating the platform from vibration. The gimbal housing includes a drive ring rotatable about a central axis and encircling the frame assembly which is connected to the drive ring. A central portion of the frame assembly carries a pivot which pivotally supports the platform. An electromagnetic actuator is located at each of a plurality of positions located circumferentially around the central axis wherein each actuator has a first part connecting with the frame and a second part connecting with of the platform to accomplish a pivoting between platform and frame assembly upon activation of each actuator.

Abstract: An optical sensor system (10), including a two degree of freedom gyro (32) and a beam expander (38) having a predetermined magnification level, is rigidly secured internally to a housing (20). Also mounted within the housing is a prime sensor beam expander (14, 16), having a magnification level equal to that of the gyro beam expander, and a prime sensor detector (30) which form a primary sensor optical path. A steering mirror (24) is interposed between the gyro and prime sensor beam expander. An autocollimator (50), including an angle detector (56), is secured internally to the housing and projects a light beam off one surface (25) of the steering mirror onto the gyro rotor (34), the position of the stabilized reflected light beam being adjusted with respect to a null point on the autocollimator sensor thus to control the steering mirror and, accordingly, to stabilize the primary optical path with respect to the target being detected.

Abstract: In a gear train where there is backlash, the backlash is prevented by a gear drive which includes an anti-backlash driven pinion which is mounted on, or is otherwise connected to, a torsion spring shaft that is adjustable for twisting, and thereby, loading the anti-backlash driven gear.