Abstract: A segmented mirror control system comprises an array of structural elements (e.g. mirrors) which can be actively positioned to maintain an accurate pre-determined overall shape. The present invention is "active" and so may be characterized as an Active Segmented Mirror Control "ASMC". The segments of a mirror or the reflecting panels, in for example, a radiotelescope, may be continually adjusted with ASMC to provide an accurate reflecting mirror of very large diameter even when disturbed by external forces. ASMC is a closed loop control system. That is, an array of sensors is first used to measure differential position errors. This data is then processed to determine position actuator commands. Finally, these commands are used to move the segments until the sensors are nulled and the desired shape is obtained.

Abstract: A adaptive flow-control regulator is disclosed for use in controlling the circulation of cooling fluid through in a cooled laser mirror. The adaptive flow-control regulator utilizes a temperature-sensitive spring to control the movement of a plunger with respect to an orifice through which cooling fluid flows. Elongation of the spring is controlled by the temperature of the cooling fluid circulating around the spring. As the temperature of the coolant fluid increases from heating of the laser mirror, the spring contracts moving the plunger away from the orifice and allowing a greater volume of coolant to circulate through the mirror, thereby absorbing a greater amount of heat from the mirror structure. As the mirror is cooled by the circulating cooling fluid, the spring moves the plunger toward the orifice, thereby reducing the volume of cooling fluid circulating through the mirror's structure.

Abstract: Hydraulic actuators are disclosed which are useful for controlling the reflecting surface of deformable mirrors or positioning the segments a segmented reflecting mirror. In one embodiment electrodistortive actuators are used to control movement of a piston into or out of a reservoir containing a fluid. The fluid controls movement of a second, smaller piston whose movement may be coupled to a surface whose shape or position it is desired to influence. In a second preferred embodiment two sets of actuators are used to permit the disclosed mechanism to impart movement in two directions to the reflecting surface or optical element whose shape or position it is desired to control.

Abstract: The invention is directed to a device for rapidly attaching glass to a metal support structure without cracking the glass. The invention consists of a C clamp with a force providing screw threadably engaged through a hole in one leg of the C clamp. The force providing screw has a spindle on one end which rides in a channel in the metal support structure. A spring, Belleville washer or other energy storing device is mounted on the spindle and is compressed against the metal support structure by the spindle base when the force providing screw is tightened. The amount of force that can be applied is limited by the combination of the screw head on the force providing screw and the longer length of the channel in relation to the spindle.

Abstract: A method for determining petal piston in a segmented optical imaging system. The system preferably comprises a center mirror and a set of P petals adjacent to the center mirror. The novel method is suitable for determining petal piston for each of the P petals, with respect to the center mirror, or with respect to each other. To this end, the novel method employs a three-part masking scheme, to simulate zero, positive and negative piston error, in order to develop a referrent as a measure of actual piston error.

Abstract: Oppositely polarized magnets are secured to a deformable mirror and a corresponding actuator. They rely on magnetic attraction to maintain the connection between the actuator and mirror. A reverse magnetic field is imposed when the actuator is to be removed for repair.

Abstract: A construction for a deformable mirror is disclosed in which each of the electrodistortive actuators used to selectively impart deformations to the mirror's reflecting facesheet are mechanically fastened to the facesheet and may be disengaged from the facesheet by operating a fusible link. In one preferred embodiment the fusible link consists of a layer of thermoplastic material covering an electrical resistive element located between the top of the actuator and the point on the facesheet at which the actuator is mechanically bonded to the facesheet. Heat generated by the resistive element may be used to melt the thermoplastic material fastening the actuator to the facesheet. The second preferred embodiment provides a fusible link consisting of an electrocapacitive layer sandwiched between two electrically-conducting layers.