Browsing by Author "Sladek, Chane"
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Item Analytical Review of Exploration Extravehicular Mobility Unit Heat Rejection Performance(2024 International Conference on Environmnetal Systems, 2024-07-21) Marsch, Robert F.; Gazzara, Sebastian P.; Sladek, Chane; Lewandowski, Michael S.; Westheimer, David T.The Primary Thermal Control Loop (PTCL) in the Exploration Extravehicular Mobility Unit (xEMU) uses a Spacesuit Water Membrane Evaporator (SWME) to provide cooling for the crewmember and spacesuit avionics. A secondary emergency cooling system, the Auxiliary Thermal Control Loop (ATCL), also uses a smaller version of the Spacesuit Water Membrane Evaporator, called the Mini-ME in the event of a failure in the primary system. These are integral in the comfort of the crewmember during an EVA through heat rejection. This paper examines the effectiveness of the heat rejection of the PTCL and the ATCL during thermal vacuum testing and the absolute limit of heat rejection to maintain an approximately 50F outlet temperature. During this thermal vacuum test, the PTCL was taken from a heat input of 0W up to 1200W, far past the design point, and the ATCL was tested from 0W to 500W. Testing showed that the PTCL and the ATCL can maintain crewmember outlet temperature throughout an entire 8hr EVA environment in hot or cold environments. The results of the test and effectiveness will be detailed throughout this paper for all EVAs.Item SERFE PLSS Component Lessons Learned from ISS(2023 International Conference on Environmental Systems, 2023-07-16) Contreras-Baker, Alicia; Westheimer, David; Sladek, ChaneNASA has been developing a new spacesuit, called the Exploration Extravehicular Mobility Unit (xEMU) for over a decade. This spacesuit is under development to support missions to the International Space Station (ISS) and also to the Moon. Improvements in the life and robustness of the Portable Life Support System (PLSS) has been a major objective of these efforts. The Suit Water Membrane Evaporator (SWME) was chosen as the technology to provide cooling to the xEMU and has undergone several iterations of development over this period. An ISS flight experiment centered around the SWME and other thermal control loop (TCL) technologies was developed and was under test in an ISS EXpedite PRocessing of Experiments to the Space Station (EXPRESS) rack from November of 2020 to August of 2022. In addition to the SWME, The SWME EXPRESS Rack Flight Experiment (SERFE) contains several technology demonstrations from the xEMU project and demonstrated their performance in micro-gravity and over an extended duration. In addition to the SWME, these included two dissimilar water pumps, custom check valves, custom bypass relieve valves, a custom thermal control valve, development pressure and temperature sensors, and the Thermal Loop Controller. This paper presents PLSS component lessons learned after return of the SERFE flight unit in August of 2022. The SERFE team took the flight unit apart and handed hardware components over to hardware owners to see how parts of the TCL managed after almost 2 years on the ISS and 25 simulated EVAs (Exploration Extravehicular Activity) on orbit. The team performed inspection, testing, and analysis and provided lessons learned on PLSS components for NASA’s prototype spacesuit. This analysis included how well SWME maintained its heat rejection capability, as well as looked at the robustness of the other TCL hardware.Item SERFE Thermal Performance Results(51st International Conference on Environmental Systems, 7/10/2022) Westheimer, David; Campbell, Colin; Contreras-Baker, Alicia; Sladek, Chane; Waguespack, GlenNASA has been developing a new spacesuit, called the Exploration Extravehicular Mobility Unit (xEMU) for over a decade. This spacesuit is underdevelopment to support missions to the International Space Station (ISS) and also to the Moon. Improvements in the life and robustness of the Portable Life Support System (PLSS) has been a major objective of these efforts. The Suit Water Membrance Evaporator (SWME) was chosen as the technology to provide cooling to the xEMU and has undergone several iterations of development over this period. An ISS flight experiment centered around the SWME and other thermal loop technologies was developed and has been under test in an ISS EXpedite PRocessing of Experiments to the Space Station (EXPRESS) rack since November of 2020. In addition to the SWME, The SWME EXPRESS Rack Flight Experiment (SERFE) contains several technology demonstrations from the xEMU project and has been demonstrating their performance in micro-gravity and over an extended duration. In addition to the SWME, these include two dissimilar water pumps, custom check valves, custom bypass relieve valves, a custom thermal control valve, development pressure and temperature sensors, and the Thermal Loop Controller. This paper presents thermal and fluids testing results of the system as a whole and of key components.Item Short xEMU Pressure Garment Thermal Vacuum Test Results(2024 International Conference on Environmnetal Systems, 2024-07-21) Swartout, Benjamin J.; Sladek, Chane; Lewandowski, Michael; Westheimer, David; Rodriggs, LianaThe 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.