Record Details

CO2 Washout Testing Using Various Inlet Vent Configurations in the Mark-III Space Suit
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Author and Affiliation:
Korona, F. Adam(Jacobs Technology, Inc., Houston, TX, United States);
Norcross, Jason(Wyle Integrated Science and Engineering Group, Houston, TX, United States);
Conger, Bruce(Jacobs Technology, Inc., Houston, TX, United States);
Navarro, Moses(NASA Johnson Space Center, Houston, TX, United States)
Abstract: Requirements for using a space suit during ground testing include providing adequate carbon dioxide (CO2) washout for the suited subject. Acute CO2 exposure can lead to symptoms including headache, dyspnea, lethargy and eventually unconsciousness or even death. Symptoms depend on several factors including inspired partial pressure of CO2 (ppCO2), duration of exposure, metabolic rate of the subject and physiological differences between subjects. Computational Fluid Dynamic (CFD) analysis has predicted that the configuration of the suit inlet vent has a significant effect on oronasal CO2 concentrations. The main objective of this test is to characterize inspired oronasal ppCO2 for a variety of inlet vent configurations in the Mark-III space suit across a range of workload and flow rates. As a secondary objective, results will be compared to the predicted CO2 concentrations and used to refine existing CFD models. These CFD models will then be used to help design an inlet vent configuration for the Z-2 space suit, which maximizes oronasal CO2 washout. This test has not been completed, but is planned for January 2014. The results of this test will be incorporated into this paper. The testing methodology used in this test builds upon past CO2 washout testing performed on the Z-1 suit, Rear Entry I-Suit (REI) and the Enhanced Mobility Advanced Crew Escape Suit (EM-ACES). Three subjects will be tested in the Mark-III space suit with each subject performing two test sessions to allow for comparison between tests. Six different helmet inlet vent configurations will be evaluated during each test session. Suit pressure will be maintained at 4.3 psid. Subjects will wear the suit while walking on a treadmill to generate metabolic workloads of approximately 2000 and 3000 BTU/hr. Supply airflow rates of 6 and 4 actual cubic feet per minute (ACFM) will be tested at each workload. Subjects will wear an oronasal mask with an open port in front of the mouth and will be allowed to breathe freely. Oronasal ppCO2 will be monitored real-time via gas analyzers with sampling tubes connected to the oronasal mask. Metabolic rate will be calculated from the total oxygen consumption and CO2 production measured by additional gas analyzers at the air outlet from the suit. Real-time metabolic rate measurements will be used to adjust the treadmill workload to meet target metabolic rates. This paper provides detailed descriptions of the test hardware, methodology and results, as well as implications for future inlet vent design and ground testing in the Mark-III.
Publication Date: Jan 01, 2014
Document ID:
(Acquired Apr 30, 2014)
Report/Patent Number: JSC-CN-29929
Document Type: Conference Paper
Meeting Information: International Conference on Environmental Systems (ICES; 44th; 13-17 Jul. 2014; Tucson, AZ; United States
Meeting Sponsor: Texas Tech Univ.; Lubbock, TX, United States
American Inst. of Aeronautics and Astronautics; Reston, VA, United States
American Inst. of Chemical Engineers; New York, NY, United States
American Society of Mechanical Engineers; Naperville, IL, United States
Financial Sponsor: NASA Johnson Space Center; Houston, TX, United States
Description: 1p; In English
Distribution Limits: Unclassified; Publicly available; Unlimited
Rights: Copyright; Distribution as joint owner in the copyright
Availability Notes: Abstract Only
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