Touch Temperature Coating for Off-the-Shelf Electrical Equipment Used on Spacecraft

Abstract

Off-the-shelf electrical equipment is frequently used in space-based applications to control costs.However, the reduced heat transfer in the spacecraft microgravity environment causes the equipment to operate at significantly higher temperatures than it would in terrestrial applications. This creates touch temperature issues where items -particularly metallic ones -become too hot for the crew to handle safely. A touch temperature coating layup has been developed that can be added to spacebased electrically powered hardware. The coating allows the crew to safely handle the hardware, but only slightly impedes the heat transfer from the component during normal operation.In the present work, the coating generic requirements are developed and a layup is described that meets these specifications. Analytical and experimental results are presented that demonstrate the ability of the coating layup to increase the allowable limits of touch temperature while only marginally degrading heat transfer to the environment. This allows the spacecraft crew to handle objects that, if not coated, would be hot enough to cause pain or skin damage. Intrndijr,tinnTo reduce costs, off-the-shelf equipment is being used more and more in the US human space program.