NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Water Vapor Permeability of the Advanced Crew Escape SuitCrew Exploration Vehicle (CEV) crewmembers are expected to return to earth wearing a suit similar to the current Advanced Crew Escape Suit (ACES). To ensure optimum cognitive performance, suited crewmembers must maintain their core body temperature within acceptable limits. There are currently several options for thermal maintenance in the post-landing phase. These include the current baseline, which uses an ammonia boiler, purge flow using oxygen in the suit, accessing sea water for liquid cooling garment (LCG) cooling and/or relying on the evaporative cooling capacity of the suit. These options vary significantly in mass, power, engineering and safety factors, with relying on the evaporative cooling capacity of the suit being the least difficult to implement. Data from previous studies indicates that the evaporative cooling capacity of the ACES was much higher than previously expected, but subsequent tests were performed for longer duration and higher metabolic rates to better define the water vapor permeability of the ACES. In these tests five subjects completed a series of tests performing low to moderate level exercise in order to control for a target metabolic rate while wearing the ACES in an environmentally controlled thermal chamber. Four different metabolic profiles at a constant temperature of 95 F and relative humidity of 50% were evaluated. These tests showed subjects were able to reject about twice as much heat in the permeable ACES as they were in an impermeable suit that had less thermal insulation. All of the heat rejection differential is attributed to the increased evaporation capability through the Gortex bladder of the suit.
Document ID
20090038874
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Bue, Grant
(NASA Johnson Space Center Houston, TX, United States)
Kuznetz, Larry
(Universities Space Research Association Houston, TX, United States)
Gillis, David
(Wyle Labs., Inc. Houston, TX, United States)
Jones, Jeffery
(NASA Johnson Space Center Houston, TX, United States)
Daniel, Brian
(NASA Johnson Space Center Houston, TX, United States)
Gernhardt, Michael
(NASA Johnson Space Center Houston, TX, United States)
Hamilton, Douglas
(Wyle Labs., Inc. Houston, TX, United States)
Date Acquired
August 24, 2013
Publication Date
July 11, 2009
Subject Category
Man/System Technology And Life Support
Report/Patent Number
JSC-CN-19215
Meeting Information
Meeting: International Conference on Environmental Systems (ICES)
Country: United States
Start Date: July 11, 2009
End Date: July 15, 2009
Sponsors: American Inst. of Aeronautics and Astronautics
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available