Browsing by Author "Swartout, Ben"
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Item Exploration Extravehicular Mobility Unit (xEMU) Chamber B Thermal Vacuum “Suit 2” Pressure Garment System Hardware and Test Design(2024 International Conference on Environmnetal Systems, 2024-07-21) Swartout, Ben; Westheimer, DavidNASA�s Exploration Extravehicular Mobility Unit (xEMU) is the government reference next-generation space suit design and is engineered to protect astronauts from extreme lunar environmental temperatures. To evaluate the xEMU hardware thermal requirements, the xEMU Testing Team invented, designed, and executed a dual-suit, uncrewed thermal vacuum (TVAC) test at Johnson Space Center�s (JSC) Chamber B. This paper details the test hardware design and test methodology for the �Suit 2� Pressure Garment System (PGS) test article. The uncrewed �Suit 2� PGS test article consisted of a full PGS assembly with simulated Portable Life Support System (PLSS) functionality provided by test equipment, including a ventilation loop and two distinct thermal control loops. This paper will discuss in depth the test hardware design, including internal suit thermal boundary simulation, sensor quantity and placement, and test support equipment rigs for gas flow, water flow, and power. Custom hardware designed to add additional penetrations to the suit or provide additional interfaces for sensors will also be discussed. This paper will also address the assembly and integration sequence for the test article. In addition to test hardware design, this paper will provide insights into the test methodology for this test article, including a discussion of thermal steady-state testing, simultaneous dual-suit thermal vacuum testing, and hazard mitigation and controls.Item Exploration Extravehicular Mobility Unit (xEMU) Chamber B Thermal Vacuum “Suit 2” Pressure Garment System Test Article Results(2024 International Conference on Environmnetal Systems, 2024-07-21) Swartout, Ben; Lewandowski, Michael; Westheimer, DavidNASA�s Exploration Extravehicular Mobility Unit (xEMU) is the government reference next-generation space suit design and is engineered to protect astronauts from extreme lunar environmental temperatures. To evaluate the xEMU hardware thermal requirements, the xEMU Testing Team invented, designed, and executed a dual-suit, uncrewed thermal vacuum (TVAC) test at Johnson Space Center�s (JSC) Chamber B. This paper details the test results from the �Suit 2� Pressure Garment System (PGS) test article. The primary objective of the �Suit 2� PGS test article was to evaluate system-level suit heat leak and environmental protection garment thermal performance. Eleven unique thermal profiles were tested, including both cold and hot environmental cases, over the course of five continuous days of testing. The radiative thermal environment was controlled through exposure to liquid-nitrogen shrouds on the chamber walls and through a heater cage surrounding the test article. This paper will principally focus on system-level thermal results from the �Suit 2� PGS test article. This paper will examine data collected from one-hundred and seventy thermocouples located in critical locations inside and outside of the suit, as well as seven resistance thermometers (RTDs) for calorimetry to determine total heat flux in and out of the suit. The test data will be compared against the system-level PGS thermal models for model validation. To conclude, this paper will address knowledge gaps presented by unmanned xPGS thermal vacuum testing and the current state of lunar PGS thermal modeling and testing.Item Exploration Extravehicular Mobility Unit (xEMU) Hard Upper Torso (HUT) Chamber B Thermal Vacuum Testing Results(2024 International Conference on Environmnetal Systems, 2024-07-21) Swartout, Ben; Meginnis, Ian; Westheimer, DavidNASA�s Exploration Extravehicular Mobility Unit (xEMU) is the government reference next-generation space suit design and is engineered to protect astronauts from extreme lunar environmental temperatures. To evaluate the xEMU hardware thermal requirements, the xEMU Testing Team invented, designed, and executed a dual-suit, uncrewed thermal vacuum (TVAC) test at Johnson Space Center�s (JSC) Chamber B. This paper details the test methodology, hardware setup, and results from the xEMU Hard Upper Torso (HUT). Two HUTs, one composite HUT and one aluminum HUT, were tested simultaneously in Chamber B with different thermal environments. For the aluminum HUT on the Short xEMU (SxEMU) test article, five thermal profiles were tested during five simulated Extravehicular Activities (EVAs). For the composite HUT on the second xEMU eleven unique thermal profiles were tested, including both cold and hot environmental cases, over the course of five continuous days of testing. The radiative thermal environment was controlled through exposure to liquid-nitrogen shrouds on the chamber walls and through a separate heater cage surrounding each respective test article. The thermal effects of the Exploration Informatics (xINFO) lights and camera on the HUT were also tested. Seventy-two temperature sensors were used to collect data in critical locations in the xEMU HUT assembly. This paper will document the testing results and compare the test data against the xEMU HUT and system-level thermal models for model validation. To conclude, this paper will address knowledge gaps presented by unmanned thermal vacuum testing with regard to the HUT and the current state of HUT thermal testing.Item Exploration Extravehicular Mobility Unit (xEMU) Helmet and Extravehicular Visor Assembly (EVVA) Chamber B Thermal Vacuum Testing Results(2024 International Conference on Environmnetal Systems, 2024-07-21) Swartout, Ben; Davis, Kristine; Westheimer, DavidNASA�s Exploration Extravehicular Mobility Unit (xEMU) is the government reference next-generation space suit design and is engineered to protect astronauts from extreme lunar environmental temperatures. To evaluate the xEMU hardware thermal requirements, the xEMU Testing Team invented, designed, and executed a dual-suit, uncrewed thermal vacuum (TVAC) test at Johnson Space Center�s (JSC) Chamber B. This paper details the test methodology, hardware setup, and results from the xEMU helmet and extravehicular visor assembly (EVVA). Two helmets/EVVAs were tested simultaneously in Chamber B, with different thermal environments and EVVA configurations. For the helmet/EVVA on the Short xEMU (SxEMU) test article, five thermal profiles were tested during five simulated EVAs, with varying visor and shade configurations. For the helmet/EVVA on the second xEMU, eleven unique thermal profiles were tested including both cold and hot environmental cases over the course of five continuous days of testing, with a single visor and shade configuration. The radiative thermal environment was controlled though exposure to liquid-nitrogen shrouds on the chamber walls and though a two separate heater cages surrounding each respective test article. The thermal effects of the Exploration Informatics (xINFO) lights and camera on the helmet/EVVA was also tested. Twenty-two temperature sensors were used to collect data in critical locations in the xEMU helmet/EVVA assembly. This paper will document the testing results and compare the test data against the xEMU helmet/EVVA and system-level thermal models for model validation. To conclude, this paper will address knowledge gaps presented by unmanned thermal vacuum testing with regard to the helmet and the current state of lunar helmet/EVVA thermal testing.Item Exploration Extravehicular Mobility Unit (xEMU) Lunar Boot Chamber B Thermal Vacuum Testing Results(2024 International Conference on Environmnetal Systems, 2024-07-21) Swartout, Ben; Fester, Zachary; Westheimer, DavidNASA�s Exploration Extravehicular Mobility Unit (xEMU) is the government reference next-generation space suit design and is engineered to protect astronauts from extreme lunar environmental temperatures. To evaluate the xEMU hardware thermal requirements, the xEMU Testing Team invented, designed, and executed a dual-suit, uncrewed thermal vacuum (TVAC) test at Johnson Space Center�s (JSC) Chamber B. This paper details the test methodology, hardware setup, and results from the xEMU lunar boots. Eleven unique thermal profiles were tested, including both cold and hot environmental cases, over the course of five continuous days of testing. The radiative thermal environment was controlled through exposure to liquid-nitrogen shrouds on the chamber walls and through a heater cage surrounding the boots. Notably, the xEMU boots also contacted the liquid-nitrogen chilled floor inside of Chamber B, which provided a conduction pathway to simulate the thermal effects of the lunar surface. Test hardware was developed to extend the water tubing from the Liquid Cooling Ventilation Garment (LCVG) into the boots to set the internal thermal boundary nominally provided by the astronaut�s foot. Thirty-three temperature sensors were used to collect data in critical locations in the xEMU boot assembly, as well as for calorimetry to determine heat flux to and from the boots. This paper will document the testing results and compare the test data against the xEMU boot and system-level thermal models for model validation. To conclude, this paper will address knowledge gaps presented by unmanned thermal vacuum testing with regard to the boots and the current state of lunar boot thermal testing.