Abstract: A gridded ion propulsion system comprising two power controllers, four ion thrusters, and two switch assemblies. One switch assembly is connected to the two power controllers and to two of the four ion thrusters. The other switch assembly is connected to the two power controllers and to the other two ion thrusters. Each switch assembly has first and second switching states which can be selected to enable either power controller to supply power to any one of the four ion thrusters. Each switch assembly comprises a respective movable body and a respective multiplicity of switches which change state in unison when the movable body changes position. For example, the movable body may be a rotatable hollow shaft driven by a stepper motor.

Abstract: An actuator is configured for transmitting a force or torque to a load. In one example configuration, the actuator includes an input device configured to apply an output force. A backstopping clutch is configured to transmit torque only in the input direction and to prevent back-driving of the input device. An overrunning clutch is configured to include a driven member moved in response to the transmitted torque in the input direction. The load may be moved in response to the driven member, or the load may be moved by a force applied directly to the load.

Abstract: An actuator is configured for transmitting a force or torque to a load. In one example configuration, the actuator includes an input device configured to apply an output force. A backstopping clutch is configured to transmit torque only in the input direction and to prevent back-driving of the input device. An overrunning clutch is configured to include a driven member moved in response to the transmitted torque in the input direction. The load may be moved in response to the driven member, or the load may be moved by a force applied directly to the load.

Abstract: The invention discloses an apparatus and method for adjusting the position of the center of mass of a mechanical structure. A typical apparatus includes a storage spool, an output spool and a flexible material having a first end coupled to the storage spool and a second end coupled to the output spool. The flexible material has a length distributed between windings of the storage spool and the output spool to adjust mass properties of an attached structure.

Abstract: The invention discloses an apparatus and method for adjusting the position of the center of mass of a mechanical structure. A typical apparatus includes a storage spool, an output spool and a flexible material having a first end coupled to the storage spool and a second end coupled to the output spool. The flexible material has a length distributed between windings of the storage spool and the output spool to adjust mass properties of an attached structure.

Abstract: There is disclosed a two-axis positioning mechanism including a single motor to control the position of two orthogonal axes. The motor is in communication with a first drive system to control the position of one axis and a second drive system to control the position of the other of the two axes. Also provided is a mechanically redundant positioning mechanism in which either of two motors may perform the two-axis positioning function.

Abstract: A method, apparatus, and an article of manufacture for determining the angular position of a shaft. The apparatus comprises a circumferentially alternating series of conducting and substantially non-conducting segments on an exterior surface of the shaft, and at least one contact surface in communication with the surface of the shaft, the contact surface sized to communicate with no more than one conducting segment at a time. Another embodiment of the present invention is described by a method of determining the angular position of a shaft by sensing a conductivity of an exterior surface of the shaft having an alternating series of conducting and substantially non-conductive surfaces, and determining the shaft angular position using the sensed conductivity of the exterior surface of the shaft.

Abstract: A method, apparatus, and an article of manufacture for determining the angular position of a shaft. The apparatus comprises a circumferentially alternating series of conducting and substantially non-conducting segments on an exterior surface of the shaft, and at least one contact surface in communication with the surface of the shaft, the contact surface sized to communicate with no more than one conducting segment at a time. Another embodiment of the present invention is described by a method of determining the angular position of a shaft by sensing a conductivity of an exterior surface of the shaft having an alternating series of conducting and substantially non-conductive surfaces, and determining the shaft angular position using the sensed conductivity of the exterior surface of the shaft.

Abstract: A deployable segmented dish-like reflector includes a main body with one or more additional reflector segments. Each reflector segment is connected to the main body with one or more link members, such that the entire reflector may be stowed into a compact volume and subsequently deployed to its operational configuration. The system provides a mechanism for stowing the at least one segment in an overlapping manner, substantially parallel to the main body, in order to minimize its stowage volume. The linkage arrangement allows the at least one reflector segment to be deployed from the stowed position to a desired final position. Rate control and deployment coordination may be introduced in a variety of ways.

Abstract: There is disclosed an angle positioning platform for positioning objects around first and second axes and a gearbox for same. The platform comprises a base, an intermediate stage, and an upper stage. The platform may have motors and first and second output gearboxes connected to the motors for driving the platform. The orientation of the stages of the platform permits the platform to be relatively compact in a stowed position and to have high angular rotation from the stowed position to a maximum travel position. The gearboxes may have a mechanism for isolating worm shafts and wormgears from heavy loads when the platform is in the stowed position. Another aspect of the invention is an output gearbox with a wormgear having stops for stopping rotation of a matingly engaged worm. Another aspect of the invention is a gearbox having torsion springs to counter backlash in the gearbox.

Abstract: A variable angle latching mechanism is provided which readily permits adjustment of the deployment angle of a solar array mechanism or other spacecraft deployable. Latch engagement is possible over a wide angular range with virtually zero backlash. In one embodiment a movable portion (20) of the latching mechanism is pivotally mounted to a stationary portion (26) of the latching mechanism and carries a catch element (10) that is adapted to move into latching engagement with a latch element (30) pivotally mounted on the stationary element. The latch element is linearly positioned on the movable portion by a single shim element(30) to thereby establish the angle of deployment of the movable member and thus the deployable. The angle of deployment of the mechanism is set at assembly by selection of shim thickness. In a second embodiment of the invention, the catch arm is an integral part of a slider which is linearly positioned by a motor.