Deployable radiator panel system

A deployable radiator panel system for a small satellite comprising:

• a fixed hinge leaf having a top end, a bottom end, and a hinge side;
• the fixed hinge leaf fastened to a spacecraft fixed radiator panel enabling conductive heat transfer from the spacecraft radiator panel to the fixed hinge leaf;
• the spacecraft radiator panel having a hinge side;
• the fixed hinge leaf hinge side having knuckles and aligned proximate the fixed radiator panel hinge side;
• the knuckles extending from proximate the fixed hinge leaf top end to proximate the fixed hinge leaf bottom end;
• a rotating hinge leaf having a top end, a bottom end, and a hinge side;
• the rotating hinge leaf fastened to a deployable radiator panel enabling heat transfer from the rotating hinge leaf to the deployable radiator panel;
• the deployable radiator panel having a radiating surface facing the spacecraft when in a stowed configuration prior to deployment, an opposite back surface, and a hinge side;
• the rotating hinge leaf hinge side having knuckles and aligned proximate the deployable radiator panel hinge side;
• wherein the knuckles are each hollow having opposite upper and lower annular surfaces and an internal cylindrical surface about an axial centerline, and wherein a hinge is formed by the rotating hinge leaf knuckles being axially aligned and interposed between the fixed hinge leaf knuckles to define a hinge axis, with an interstice between each knuckle lower annular surface and the adjacent knuckle upper annular surface, the hinge further comprising a hinge pin having a cylindrical surface retained within the knuckles along the hinge axis, with an interstice between the hinge pin cylindrical surface and each knuckle internal cylindrical surface being about the same size as the interstice between adjacent knuckles;
• and
• wherein the deployable radiator panel system further comprises fusible metal substantially filling the interstices between each adjacent knuckle and between each knuckle and the hinge pin, and further wherein the fusible metal, when solid, provides metallic connectivity for conductive heat transfer between the fixed hinge leaf and the rotating hinge leaf.

A method for providing heat rejection from a small satellite comprising:

• providing a fusible metal thermal hinge having a top end and a bottom end, the fusible metal thermal hinge having a fixed hinge leaf and a rotating hinge leaf, each leaf having alternating substantially cylindrical knuckles spaced from each other by an interstice, each knuckle having an axial centerline substantially aligned with the centerlines of the other knuckles to define a hinge axis extending from the hinge top end to the hinge bottom end, each interstice substantially filled with fusible metal, the fusible metal thermal hinge in an open position with respect to the fixed hinge leaf in relation to the rotating hinge leaf;
• attaching the fixed hinge leaf to a spacecraft fixed radiator panel and the rotating hinge leaf to a deployable radiator panel;
• installing a heater proximate the fixed hinge leaf knuckles and a temperature sensor proximate the heater;
• installing a deployment spring and a deployment damper;
• installing a latch, and a latch spring holding the fusible metal thermal hinge in the open position;
• installing a launch lock on the deployable radiator panel;
• heating the fusible metal thermal hinge to melt the fusible metal, releasing the latch, and moving the deployable radiator panel to a closed position, engaging the launch lock to retain the deployable radiator panel in the closed position;
• cooling the fusible metal thermal hinge to solidify the fusible metal;
• launching the small satellite;
• commanding the heater to heat the fusible metal thermal hinge to a design temperature measured by the temperature sensor sufficient to melt the fusible metal;
• commanding the launch lock to open allowing the deployment spring and deployment damper to rotate the deployable radiator panel into a deployed position engaging the latch;
• commanding the heater to turn off, allowing the fusible metal to cool and solidify;
• whereby heat from the spacecraft fixed radiator panel is conducted to the deployable radiator panel by a heat transfer path through the fixed hinge leaf to the metallic fusible metal in solid form, in turn to the rotating hinge leaf, and finally to the deployable radiator panel.