Small satellites with their low thermal capacitance are vulnerable to rapid temperature fluctuations. Therefore, thermal control becomes important, but the limitations on mass and electrical power require new approaches. Possible solutions to actively vary the heat rejection of the satellite in response to variations in the thermal load and environmental condition are the use of a variable emissivity coating (VEC), micro-machined shutters and louvers, or thermal switches. An elegant way the radiate heat is to switch the thermal contact between the emitting surface and the radiator electrostatically. This paper describes the design and fabrication of an active radiator for satellite thermal control based on such a micro electromechanical (MEMS) thermal switch. The switch operates by electrostatically moving a high emissivity surface layer in and out of contact with the radiator. The electromechanical model and material considerations for the thermal design of the MEMS device are discussed. The design utilizes a highly thermal conductive gold membrane supported by low-conductance SU-8 posts. The fabrication process is described. Measured actuation voltages were consistent with the electrostatic model, ranging from 8 to 25 volts.
MEMS thermal switch for spacecraft thermal control
2004
8 Seiten, 7 Quellen
Aufsatz (Konferenz)
Englisch
MEMS Shutters for Spacecraft Thermal Control
AIAA | 2002
|AIAA-2002-5766 MEMS Shutters for Spacecraft Thermal Control
British Library Conference Proceedings | 2002
|SLUB | 2012
|NTIS | 1973