Abstract: A deployable reflector having an umbrella-like structure in which a plurality of tubular parabolically curved ribs are connected end-wise to a central hub by associated strain energy hinges, which are flexible and spring-like in characteristic, creating a spring force when stressed. A thin pliant metal coated film material is shaped for expansion into a parabolic shape serves as the reflective surface. Rib anchors, suitably radially extending pockets, attached to the backside of the material receive the ribs that radially extend from the hub. When stowed and restrained, such as by a cable, the curved ribs are all held down, collapsing the parabolic shape of the material, and stressing the hinges, which produce a counter-biasing force. When the restraining force is released to deploy the reflector, the biasing force created in the spring-like flexible hinges automatically pivots the ribs outwardly, pulling the material into its parabolic shape.

Abstract: A vibration control system is provided for an appendage such as an antenna 10 coupled to a platform such as a spacecraft 12. The antenna 10 is coupled at a base 14 so as to extend from the spacecraft 12. A plurality of guidelines 20 extend between remote portions 22 of the antenna 10 and the antenna base 14. A plurality of motion control elements 36 are provided within the antenna structure for reducing oscillation settling time of the antenna 10 relative to the spacecraft 12. The motion control elements 36 include a material disposed therein having its damping response changed according to the magnitude of an electric or magnetic field applied thereto.

Abstract: A deployable perimeter truss reflector is capable of achieving a hitherto unobtainable thirty to one ratio in size between its size in the deployed condition and the stowed condition. The improved truss reflector structure is characterized by deployable spars that are attached to and extend from a basic frame structure to the truss. When deployed the spars are positioned outwardly and away from the basic frame of the truss, carrying the catenaries, and, the latter carrying the reflective surface into position at an end of the truss cylindrical truss. New catenary systems, deployment mechanisms, basic truss structures and cable management systems are also described.

Abstract: A precision deployable boom assembly 10 for terrestrial and celestial applications comprises an extendable and retractable boom 12 having a fixed end 14, a movable distal end 20 and three or more cables 30 attached to the distal end to form a tripod configuration of the deployed boom. The boom is spring biased to urge extension of the boom and to produce a tensile pre-load in the cables. The cables are wound and unwound by cable drums 28 selectively driven by precise motors such as stepping motors 33. The cables are preferably formed of graphite which provides high stiffness, light weight and a very low coefficient of thermal expansion. The position of the distal end is highly stable at all deployed lengths of the boom and is also precisely repeatable.