Exploration PLSS Thermal Desktop Modeling

The Exploration Portable Life Support System (xPLSS) maintains life support for a suited crew member during Extravehicular Activity (EVA). The thermal and pneumatic/hydraulic interactions within the xPLSS have been modeled using Thermal Desktop ®. In addition to these interactions, a human thermal model (METMAN) that includes metabolic, respiration, muscular work, and active body thermoregulation, was used to include the crew member as part of the loop. The model is a system level simulation and is being used to estimate thermal boundary conditions for detailed xPLSS component analyses. To date, this model has been used to evaluate the cooling system capabilities for keeping the crew member comfortable in a range of thermal environments and off nominal operating conditions, the thermal and pressure conditions during failed open relief valve scenarios, temperature effects on the removal efficiencies of the carbon dioxide and humidity control unit and detailed thermal analysis of batteries. In summary, this Thermal Desktop ® is supporting many of the design review products for the xPLSS as it comes to maturity and providing insight into the operations of the xPLSS in many operating conditions and scenarios.