The Advanced Camera for Surveys is an instrument containing two charged-coupled device (CCD) cameras and a multi-anode multichannel array (MAMA) detector being built by Ball Aerospace and Technologies Corporation for NASA. The instrument is scheduled to be installed in the Hubble Space Telescope during a space shuttle mission in December 1999. The CCD detectors need to operate at a temperature below -80*C in order to avoid unacceptable dark current. This cooling is achieved with thermo-electric coolers (TEC) mounted in evacuated assemblies that contain the detectors. The heat that is generated by the TEC's must be dissipated to space. Since the CCD assemblies are centrally located within the instrument enclosure, a method must be provided for transferring this heat to a heat rejection surface. Heat pipes have been selected since they are frequently used in space applications for passively transferring heat from sources to remotely located radiating panels. The alignment of the CCDs is critical, however, so the loads induced into the detectors and the optical bench containing the sensor assemblies through heat pipes must be minimized. Consequently, the CCD heat pipes have been designed with a flexible section to minimize either thermally-generated or launch-induced structural loads. Structural and thermal testing has shown that these heat pipes will allow the ACS detectors to attain their operating temperature while meeting alignment stability requirements. This paper will present the design of and test results from the ACS flexible heat pipes.
Keywords: HST Advanced Camera, CCDs, heat pipes
Brief Biography, Principal Author:
Russell B. Schweickart is a senior analyst in the cryogenics division at Ball Aerospace and Technologies Corporation. He received a Bachelors of Science degree from the California Institute of Technology and a Masters of Science in Mechanical Engineering from Stanford University. He previously worked on the development and modeling of capillary pumped loops at NASA Goddard Space Flight Center.
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