Pressure infiltration cast graphite fiber and platelet reinforced Al materials are proposed. Structural materials that have high stiffness, low thermal expansion, very high thermal conductivity and low density will be developed for use as a satellite structural frame. The same composite preform architecture used in the frame will be applied to satellite panels so as to produce zero difference in coefficient of thermal expansion between the frame and the attached panels. With >600 W/mK thermal conductivity and less than 4 ppm/K thermal expansion, the frame/panel structure will be thermally stable as the beta angle associated with low earth orbit changes and the mission thermal load varies. Hot spot remediation is provided along with local CTE control at electronic mounting sites so that the panels also serve as a passive thermal management system. High heat capacity attachments, strategically located near the electronic/sensor heat source will provide for a low mass passive thermal leveler to prevent extreme temperature variation during complex duty cycles. The structure will have twice the stiffness, three times the thermal transport capacity and 15% of the thermal expansion of an Al structure.
Benefit: Passive thermal management will permit greater flexibility in payload instrumentation design and denser electronics. Passive thermal leveling will eliminate temperature extremes and enable greater reliability and life. Lower mass associated with higher stiffness structures enables increased instrumentation in the payload. The technologies developed will have applications in electronic chassis as well as for main-frame and server center thermal management.
Keywords: Satellite Structures, Metal Matrix Composites, Graphite Fibers, Graphite Platelets, Thermal Conductivity, Thermal Expansion, Thermal Storage, Thermal Management
