The Exploration Extravehicular Mobility Unit (xEMU) project performed a thermal vacuum test of development-verification-test (DVT) fidelity hardware in Chamber B at the Johnson Space Center. One of the spacesuits tested was in the Short xEMU (SxEMU) configuration which included the fully assembled Exploration Portable Life Support System (xPLSS) and a partial configuration of the Exploration Pressure Garment System (xPGS). xPGS components includes the Hard Upper Torso (HUT), hatch, shoulders, arms, helmet and visor assemblies. Since this test article had the complete xPLSS, emphasis during testing was directed towards evaluating its performance by running metabolic loads at different thermal environments. Therefore, the HUT was filled with instrumentation to verify performance of the life support system. This internal instrumentation package did not provide an internal thermal boundary for the suit that simulated a person wearing a Liquid Cooling Garment (LCG) well, so some testing concessions were made when setting testing environments for the xPGS components to ensure hardware temperature limits were not exceeded. In spite of these limitation, external temperatures ranging between 40°F and 170°F were achieved and can be correlated against previous thermal models. This unmanned thermal-vacuum test was a unique configuration that provided valuable data on the xEMU design and also services as reference point for future spacesuit thermal-vacuum tests.
Swartout et al. (2024) studied this question.