Exploration EVA Suit Thermal Performance in a Variety of Environments

An Exploration Suit Thermal Analysis assessed the thermal performance of the notional Exploration Suit in Extravehicular Activity (EVA) environments. The analysis predicts the thermal response of both crewmember and notional spacesuit in EVA environments using an upgraded version of the latest NASA version of the Wissler Human Thermal Model. Analysis cases were run for EVA radiation sink environments ranging from -314 °F (Earth- Moon Lagrange point 2 (EML2) Cold) to +231 °F (Lunar Surface Hot). Each case thermally simulated an 8-hour EVA starting from a thermal neutral pre-breathe. It was found that thermal comfort is good across a wide range of sink environments if metabolic rates are constant, but transient metabolic rate profiles are considerably more difficult to support in a wide range of environments. Sweating is a serious problem with large water loss rates in hot environments. A wide LCG water inlet temperature range with frequent changes in temperature is needed to deal with widely variable transient metabolic profiles.