Heat Exchanger/Humidifier Trade Study and Conceptual Design for the Constellation Spacesuit Portable Life Support System Ventilation Subsystem

As development of the Constellation spacesuit element progresses, designing the most effective and efficient life support systems is critical. The baseline schematic analysis for the Portable Life Support System indicates that the ventilation loop will need some method of heat exchange and humidification prior to entering the helmet. A trade study was initiated to identify the challenges that are associated with conditioning the spacesuit breathing gas stream for temperature and water vapor control; to survey technological literature and resources on heat exchanger and humidifiers to provide solutions to the problems of conditioning the spacesuit breathing gas stream; and to propose potential candidate technologies to perform the heat exchanger and humidifier functions. This paper summarizes the results of this trade study, and also describes the conceptual designs that NASA developed to address these issues.