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: 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: A mass damper is provided for damping a mass. The mass damper includes a housing configured to couple to the mass and a plurality of electrostatically charged particles disposed within the housing, where the particles do not clump to one another or stick to the housing.

Abstract: A control system of a spacecraft for controlling two or more sets of collinear control moment gyroscopes (CMGs) comprises an attitude control system. The attitude control system is configured to receive a command to adjust an orientation of the spacecraft, determine an offset for a momentum disk for each of the two or more sets of CMGs that maximizes torque, determine a momentum needed from the two or more sets of CMGs to adjust the orientation of the spacecraft, and calculate a total torque needed by taking the derivative of the momentum. The control system further comprises a momentum actuator control processor coupled to the attitude control system, the momentum actuator control processor configured to calculate a required gimbal movement for each of the CMGs in each of the two or more sets of collinear CMGs from total torque.

Abstract: Methods and apparatus are provided for reaction wheel (RW) assemblies for spacecraft. The apparatus comprises a M/G coupled to an inertia wheel and a controller coupled to the M/G that, in response to commands it receives, couples power to or from an M/G of another RW assembly over a shared transfer connection (VXFR), so that one M/G acts as a generator powering another M/G acting as a motor. The controller compares generator voltage VGEN to the BEMF of the motor on VXFR and reconfigures a multi-winding M/G or steps-up the generated voltage to maintain VGEN>VXFR to maximize direct energy transfer from one RW to the other as long as possible. When VGEN declines sufficiently, the controller can couple the motor to the spacecraft power bus and/or the generator to a power dump so as to continue to provide the commanded torque if needed. Operation is automatic.

Abstract: A system is provided for docking two vehicles. In one exemplary embodiment, the system includes a first and a second vehicle. The first vehicle has a port thereon. The port has a first magnetic mechanism coupled thereto, and the first magnetic mechanism is configured to provide a first magnetic polarity. The second vehicle is in communication with the first vehicle and has an interface thereon. The interface has a second magnetic mechanism coupled thereto and is configured to selectively provide a first and a second magnetic polarity. The first and second magnetic mechanisms are magnetically attracted to one another when the second magnetic polarity is selected and repel one another when the first magnetic polarity is selected.

Abstract: An spacecraft control system is provided that includes a tube and a plurality of microwheels. The plurality of microwheels is disposed within the tube. Each microwheel has a first stator wafer, a second stator wafer, and a rotor wafer disposed therebetween. The first and second stator wafers are configured to spin the rotor wafer.

Abstract: A mass damper is provided for damping a mass. The mass damper includes a housing configured to couple to the mass and a plurality of electrostatically charged particles disposed within the housing, where the particles do not clump to one another or stick to the housing.

Abstract: A momentum actuator for steering a spacecraft is disclosed. The momentum actuator comprises a rotor, a gimbal upon which the rotor is mounted, and a stepper motor coupled to the gimbal and operable to rotate the rotor about the gimbal in a series of steps. In one embodiment of the present invention the spin rate of the rotor can be varied to provide torque.

Abstract: The present method provides a method for avoiding singularities in the movement of CMGs in an array of CMGs in a spacecraft. In a first step, a torque command representing a desired torque to produce an attitude adjustment for the spacecraft is received. Next, a range-space gimbal rate required to produce the desired torque based on the desired torque and a Jacobian matrix is calculated. Then, a null-space gimbal rate that assists in the avoidance of singularities is calculated. The total gimbal rate command is determined by summing the range-space gimbal rate and the null-space gimbal rate. Then, the total gimbal rate command is provided to the CMGs to produce the total gimbal rate.

Abstract: A momentum-control system for a spacecraft is disclosed. The momentum-control system comprises an attitude-control system. The attitude-control system receives data concerning a desired spacecraft maneuver and determines a torque command to complete the desired spacecraft maneuver. A momentum actuator control processor coupled to the attitude-control system receives the torque command. The momentum actuator control processor calculates a gimbal rate command comprising a range-space gimbal rate required to produce the torque command and a null-space gimbal rate required to maximize the ability to provide torque in the direction of a current torque. At least four control-moment gyros are coupled to the momentum control actuator control processor. Each of the control-moment gyros receives and executes the gimbal rate to produce the desired maneuver.

Abstract: The present invention discloses a momentum-control system. The momentum-control system comprising a plurality of momentum actuators and a platform, upon which the plurality of momentum actuators are mounted. The momentum control system further comprises a plurality of active struts mounted on the bottom side of the platform. The active struts are configured to produce a force to steer the plurality of momentum actuators and the platform to produce forces and moments for spacecraft attitude control and disturbance suppression.

Abstract: Methods and apparatus are provided for reorienting control moment gyros (CMGs) to compensate for CMG failure or change in spacecraft (S/C) mass properties or mission. An improved CMG comprises a drive means for rotating the CMG around an axis not parallel to the CMG gimbal axis. Releasable clamps lock the CMG to the spacecraft except during CMG array reorientation. CMGs arrays are combined with attitude sensors, a command module, memory for storing data and programs, CMG drivers and sensors (preferably for each CMG axis), and a controller coupling these elements. The method comprises determining whether a CMG has failed or the S/C properties or mission changed, identifying the working CMGs of the array, determining a new array reorientation for improved spacecraft control, unlocking, reorienting and relocking the CMGs in the array and updating the S/C control parameters for the new array orientation.