Browsing by Author "Meginnis, Ian"
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Item Characterization of the Nasal Cannula as a Carbon Dioxide Washout Measurement Technique in the Mark III Space Suit(46th International Conference on Environmental Systems, 2016-07-10) Meginnis, Ian; Norcross, Jason; Bekdash, Omar; Ploutz-Snyder, RobertA space suit must provide adequate carbon dioxide (CO2) washout inside the helmet to prevent symptoms of hypercapnia. In the past, an oronasal mask has been used to measure the inspired air of suited subjects to determine a space suit’s CO2 washout capability during ground-based tests. Although sufficient for super-ambient pressure testing of space suits, the oronasal mask fails to meet several human factors and operational criterion needed for future sub-ambient pressure testing (e.g., compatibility with a Valsalva device). This paper describes the evaluation of a nasal cannula as a device for measuring inspired air within a space suit. Eight test subjects were tasked with walking on a treadmill or operating an arm ergometer to achieve target metabolic rates of 1000, 2000, and 3000 British thermal units per hour (BTU/hr) at helmet ventilation flow rates of 2, 4, and 6 actual cubic feet per minute (ACFM). The test points at lower metabolic rates were conducted twice, with subjects instructed to breathe either through the nose only or however they felt comfortable. Comparing nasal cannula test data to historical oronasal mask data shows that the nasal cannula provides more statistically consistent data across test subjects than the oronasal mask, regardless of the breathing style. The data also shows that inhaling/exhaling through only the nose provides a lower sample variance than an unrestricted breathing style. However, it may not be realistic to require nose-only breathing for future CO2 washout evaluations because test subjects cannot breathe through their nose continuously at high metabolic rates. The test subjects in this study also provided feedback to human factors criteria, reporting that the nasal cannula is comfortable and can be used with a Valsalva device.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 NASA Advanced Space Suit xEMU Development Report -- Hard Upper Torso Assembly(51st International Conference on Environmental Systems, 7/10/2022) Meginnis, Ian; Rhodes, Richard; Kim, DanielFor the past several years, the Exploration Extra-Vehicular Mobility Unit (xEMU) team at NASA's Johnson Space Center has focused on the development and detailed design of the xEMU to support missions to the International Space Station (ISS) and a moon landing in 2024. In that context, this paper examines the development and baseline detailed design of the xEMU Hard Upper Torso (HUT) Assembly. This paper will outline the challenging technical requirements, significant architectural trades, technical solutions required to overcome these challenges, and a status of the detailed design. The preliminary results of Design Verification Testing (DVT) as it relates to the HUT will also be provided, along with a forward strategy for final maturation into a flight-ready design.Item NASA Advanced Space Suit xEMU Development Report-- Integrated Communication System(51st International Conference on Environmental Systems, 7/10/2022) Meginnis, Ian; Foster, WilliamFor the past several years, the Exploration Extra-Vehicular Mobility Unit (xEMU) team at NASA's Johnson Space Center (JSC) has focused on development and testing of the xEMU to support missions to the International Space Station (ISS) and a moon landing in 2024. In that context, this paper examines the development and detailed design of the xEMU Integrated Communication System (ICS). This paper outlines the challenging technical requirements, significant architectural trades, technical solutions required to overcome these challenges, and a status of the detailed design. The preliminary results of Design Verification Testing (DVT) as it relates to the ICS are also provided, along with a forward strategy for final maturation into a flight-ready design.Item NASA Advanced Space Suit xEMU Development Report-- Shoulder Assembly(51st International Conference on Environmental Systems, 7/10/2022) Meginnis, Ian; McFarland, Shane; Rhodes, Richard; Watters, Jeff; Cox, DavidFor the past several years, the Exploration Extravehicular Mobility Unit (xEMU) team at NASA's Johnson Space Center (JSC) has focused on the development and detailed design of the xEMU to support missions to the International Space Station (ISS) and a moon landing in 2024. In that context, this paper examines the development and baseline detailed design of the xEMU Shoulder Assembly. This paper will outline the challenging technical requirements, significant architectural trades, technical solutions required to overcome these challenges, and a status of the detailed design. The preliminary results of Design Verification Testing (DVT) as it relates to the shoulder will also be provided, along with a forward strategy for final maturation into a flight-ready design.Item NASA Advanced Space Suit xEMU Development Report-- Wired Heart Rate Monitor(51st International Conference on Environmental Systems, 7/10/2022) Meginnis, Ian; Woodbury, Christopher; Rivera, Jorge; Jennings, Michael; Sreedhar, SreeFor the past several years, the Exploration Extra-Vehicular Mobility Unit (xEMU) team at NASA's Johnson Space Center (JSC) has focused on development and testing of the xEMU to support missions to the International Space Station (ISS) and a moon landing in 2024. In that context, this paper examines the development and detailed design of the xEMU Wired Heart Rate Monitor (WHRM). This paper outlines the challenging technical requirements, significant architectural trades, technical solutions required to overcome these challenges, and a status of the detailed design. The preliminary results of Design Verification Testing (DVT) as it relates to WHRM are also provided, along with a forward strategy for final maturation into a flight-ready design.Item Performance of the Z-2 Space Suit in a Simulated Microgravity Environment(48th International Conference on Environmental Systems, 2018-07-08) Meginnis, Ian; Davis, Kristine; Rhodes, RichardThe Z-2 space suit is the product of the last fifty years of NASA’s space suit research and testing experience. The suit was originally built as a prototype exploration space suit to evaluate advances in suit design and technology for use on a planetary surface. After the delivery of Z-2, however, NASA shifted focus and sought to evaluate the feasibility of using design features of the Z-2 suit to inform the design of the xEMU Demo space suit, which will be demonstrated on the International Space Station (ISS). Aside from being developed primarily to evaluate the overall architecture of the xEMU space suit, the xEMU Demo may also supplement or replace the existing Extravehicular Mobility Unit (EMU). To evaluate the microgravity performance of the Z-2 architecture for compatibility on the ISS, the suit was tested in NASA’s Neutral Buoyancy Laboratory (NBL), which is the primary microgravity testing environment for space suits. The Z-2 NBL test series began in the fall of 2016 and concluded in the fall of 2017. Five astronauts performed various tasks that are representative of the tasks performed on the ISS. Test subjects performed tasks in the Z-2 suit and the EMU so that relative comparisons could be drawn between the two suits. Two configurations of the Z-2 space suit were evaluated during this test series: the ELTA configuration and the ZLTA configuration. The ELTA configuration, which was the primary test configuration, is comprised of the Z-2 upper torso and the EMU lower torso. The ZLTA configuration is comprised of the Z-2 upper torso with the Z-2 lower torso, which contains additional mobility elements. This paper discusses the test results from the Z-2 NBL test series.Item Testing of the NASA Exploration Extravehicular Mobility Unit Demonstration (xEMU Demo) Architecture at the Neutral Buoyancy Laboratory(49th International Conference on Environmental Systems, 2019-07-07) Davis, Kristine; Meginnis, IanFollowing Z-2 space suit testing that occurred from 2016-2017, the Exploration Extravehicular Mobility Unit (xEMU) Project was tasked with building a demonstration unit of the xEMU space suit to test on the International Space Station (ISS) in 2023. This suit is called xEMU Demonstration Suit (xEMU Demo). Based on feedback from astronauts during the Z-2 NBL test series, design changes were made, resulting in a new prototype suit called the Z-2.5 space suit. The design of the Z-2.5 space suit with an exploration Portable Life Support Systems (xPLSS) mock-up represents the architecture of xEMU Demo. The team is testing Z-2.5 in the NBL to evaluate this architecture and validate changes made from Z-2. The results will inform the xEMU Demo design going forward to its Preliminary Design Review (PDR) in the summer of 2019. This Z-2.5 NBL test series focuses on evaluating the microgravity performance of the suit and the ability to complete ISS-related tasks. The series is comprised of 10 manned runs and an unmanned corn-man run. Six test subjects, including four astronauts, will participate. The test objective is to evaluate ability xEMU Demo architecture to perform ISS microgravity tasks. Each crew members will complete both a familiarization run and a nominal EMU EVA timeline run. Qualitative and quantitative data will be collected to aid the assessment of the suit. Preliminary feedback from astronauts who have completed the test series evaluate the xEMU Demo architecture as acceptable to complete a demonstration mission on the ISS.Item Testing of the Z-2 Space Suit at the Neutral Buoyancy Laboratory(47th International Conference on Environmental Systems, 2017-07-16) Meginnis, Ian; Rhodes, Richard; Larson, Kristine; Ross, AmyThe Z-2 space suit is the product of the last fifty years of NASA’s space suit research and testing experience. The Z-2 suit was originally developed as an exploration space suit for use on a planetary surface, such as the moon or Mars. However, Z-2 could also be used in microgravity at the International Space Station (ISS) to supplement or replace the existing Extravehicular Mobility Unit (EMU). To evaluate the microgravity performance of Z-2 for compatibility at the ISS, the suit was tested in NASA’s Neutral Buoyancy Laboratory, which is the primary microgravity testing environment for space suits. Seven test subjects, including five astronauts, performed various tasks that are representative of the tasks performed at the ISS. Test subjects performed tasks in the Z-2 suit and the EMU so that relative comparisons could be drawn between the two suits. Two configurations of the Z-2 space suit were evaluated during this test series: the ELTA configuration and the ZLTA configuration. The ELTA configuration, which was the primary test configuration, is comprised of the Z-2 upper torso and the EMU lower torso. The ZLTA configuration is comprised of the Z-2 upper torso with the Z-2 lower torso, which contains additional mobility elements. This paper discusses the test methodology and preliminary test results from the Z-2 NBL test series.Item Validation of Inspired Carbon Dioxide Measurement Methods in the Extravehicular Mobility Unit Space Suit(48th International Conference on Environmental Systems, 2018-07-08) Bekdash, Omar; Norcross, Jason; Fricker, John; Meginnis, Ian; Abercromby, Andrew; Young, MillenniaNASA seeks a validated, standardized methodology for measuring the inspired carbon dioxide gas (CO2) in Extravehicular Activity (EVA) and Launch, Entry, Abort (LEA) pressure suits to verify that ventilation designs maintain safe levels of CO2 during all suited operations. To date, various methods have been used to assess the CO2 washout capability of different spacesuits using a variety of in-suit sampling techniques and devices, however, none have enabled adoption of a standard method applicable to all space suit testing. Previous work conducted at the NASA Johnson Space Center characterized inspired CO2 measurement equipment and methods to develop a standard method for verification of suit CO2 washout performance. This method minimizes and quantifies test equipment induced measurement error, and defines the analysis methods for calculation of the in-suit inspired CO2 and washout performance. In this follow-on study, human-in-the-loop (HITL) testing was completed using the Extravehicular Mobility Unit (EMU) to validate this new methodology and gather data for characterization of the washout performance of the longest continually operating EVA space suit design. This included sample probe efficacy assessment, analysis of the potential importance of subject selection during HITL CO2 washout testing by gathering physiological data characterizing intra-subject and inter-subject variability, and collection of in-suit transcutaneous CO2 measurements for added contextual evidence of washout performance. Data collected in this methodology validation will be used to characterize the EMU which will ultimately inform the development of standard test practices and provide data for evidence-based in-suit CO2 exposure requirements.