Validation of Inspired Carbon Dioxide Measurement Methods in the Extravehicular Mobility Unit Space Suit

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48th International Conference on Environmental Systems

NASA 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.

Omar Bekdash, KBRWyle
Jason Norcross, KBRWyle
John Fricker, Oceaneering
Ian Meginnis, National Aeronautics and Space Administration (NASA), USA
Millennia Young, National Aeronautics and Space Administration (NASA), USA
ICES400: Extravehicular Activity: Space Suits
The 48th International Conference on Environmental Systems was held in Albuquerque, New Mexico, USA on 08 July 2018 through 12 July 2018.
CO2 Washout, Inspired CO2 Measurement, EVA, Extravehicular Mobility Unit (EMU)