Abstract: An attitude control system for a spacecraft is disclosed that includes a scissored pair of control moment gyroscopes for delivering an output torque to the spacecraft along a an output axis, wherein each gyroscope has a spin motor for spinning a rotor about a rotor axis and a gimbal torque motor for rotating the rotor about a gimbal axis, and wherein the system includes a generator for extracting kinetic energy from the rotors during rotor deceleration to power the gimbal torque motors of the gyroscopes.

Abstract: A control moment gyroscope system for delivering a target torque to a spacecraft including a rotor assembly having a rotor and a motor to spin the rotor about a rotor axis. A gimbal assembly has a gimbal for supporting the rotor assembly and a gimbal torque motor to rotate the gimbal about a gimbal axis, which is normal to the rotor axis, to generate an output torque. A control system has a sensor for determining the output torque and a processor in communication with the rotor assembly, the gimbal assembly and the sensor. The processor requests the target torque and establishes a feedback control loop to generate a torque error signal based on the output torque for bringing the output torque within a predetermined range of the target torque.

Abstract: An attitude control system for a spacecraft is disclosed that includes a scissored pair of control moment gyroscopes for delivering an output torque to the spacecraft along a an output axis, wherein each gyroscope has a spin motor for spinning a rotor about a rotor axis and a gimbal torque motor for rotating the rotor about a gimbal axis, and wherein the system includes a generator for extracting kinetic energy from the rotors during rotor deceleration to power the gimbal torque motors of the gyroscopes.

Abstract: A sun sensor for use in orbiting satellites provides accurate attitude control yet eliminates the use of complicated optical components. The improved accuracy results from adjustment of the relative positions of a slit or pinhole aperture and a cooperating linear array of photodetector elements to increase the operating range of the sun sensor. Enhanced accuracy is further achieved by the use of a relatively wide slit instead of complicated optical components, in conjunction with a processing procedure which uses the finite angular subtense of the sun to increase the accuracy of the attitude control of the satellite by the sun sensor. A further embodiment of the invention includes a sun sensor device having dual "pinhole" apertures which is particularly useful for attitude control of a spinning satellite.

Abstract: An earth horizon sensor on board an orbiting spacecraft is designed to produce four (4) scans across the earth at geosynchronous altitudes using only two non-visible wavelength (infrared) detectors. The four scans are essentially parallel and permit the earth center to be offset from the null axis of the earth sensor permitting the offset pointing of high gain communication. By providing four scans using only two detectors, components are minimized and reliability is improved. The four scans are generated with only two detectors by using both the front and rear surfaces of a rotating scanning mirror.