Date of Award

January 2019

Document Type


Degree Name

Master of Science (MS)


Space Studies

First Advisor

Pablo de Leon


The technology of a liquid-cooled garment allows astronauts to complete extravehicular activities while maintaining a degree of thermal comfort. The garment has gone largely unchanged despite advancements in technology, materials, and knowledge. This research examines possible advancements in thermal efficiency with an alternate tubing geometry through heat transfer rate calculations. A semi-circle cross-section was selected and compared against the current circular cross-section tubing. Each tubing cross-section was 3-D printed and integrated into forearm sleeves. For comparison, the assembly of each sleeve resembled the current Liquid Cooling and Ventilation Garment used with the Extravehicular Mobility Unit. Subjects wore the forearm sleeves while water at 25 °C, 18 °C, and 10 °C flowed through the tubing. Skin surface temperatures from the four test subjects were recorded with thermocouples before and during the experiments. The data collected from this research supported the conclusion that semi-circle cross-section tubing provides an average 24.5% greater heat transfer compared to circular cross-section tubing. The ANOVA analysis suggests there is some statistical significance in the heat transfer rates between the two tubing cross-sections. Further data analysis implies that the semi-circle cross-section tubing could provide increased thermal regulation based on a decrease in skin temperature.