CO2 Washout Capability with Breathing Manikin

Carbon Dioxide (CO2) Washout performance is a critical parameter needed to ensure proper and sufficient designs in a spacesuit and in vehicle applications such as sleep stations and hygiene compartments.  Human testing to fully evaluate CO2 washout is expensive due to the levied safety requirements. Moreover, correlation of math models becomes challenging because of human variability and movement.  A breathing capability will be integrated into a Suited Manikin Test Apparatus (SMTA) to provide a safe, lower cost, stable, easily modeled alternative to human CO2 washout testing. Lastly, this configuration provides JSC the capability to evaluate carbon dioxide washout under off-nominal conditions that would otherwise be unsafe for human testing or difficult due to fatigue of a test subject.

The intent of this particular project was to perform the following: Provide a breathing capability to be integrated into existing EC5 Ventilation Lab Suited Manikin Test Apparatus (SMTA).  Evaluate flow controllers and ancillary equipment needed to provide breathing function including proper CO2 and humidity levels varying appropriately with simulated metabolic rate profiles. The SMTA will be upgraded to include the fully capable breathing apparatus components that will be sufficient to simulate human breathing providing the capability to rapidly explore the range of human metabolic activity expected during Extravehicular Activity (EVA).    Testing performed with the SMTA will benefit development efforts including Advanced Exploration Systems (AES) Advanced Extravehicular Mobility Unit (AEMU) Helmet and Portable Life Support System (PLSS) development and Space Technology Mission Directorate Rapid Cycling Amine development.  Future upgrades to the SMTA could include the capability to include various helmet designs, human head geometries and positions, and ventilation inlet configurations.  Moreover, the test apparatus will be directly applicable to validating future suit air revitalization hardware and flow components as new technologies become available.