Short Title: Hypobaric Hypoxia Last Published:  11/23/20 11:55:09 AM (Central)
Element: Human Health Countermeasures (HHC)
Evidence:  Report
Risk Master Logic Diagram:  Diagram
Point of Contact:  Jason Norcross
HRP Risk Status: Inactive [no current ongoing research]
Inactive Rationale
While Exploration Atmosphere research and operational development is of high importance, much of this work is now funded by organizations other than HRP, in a collaborative joint effort with HRP as a stakeholder. Details of the work that is already being done (or planned to be done) may be found in the comprehensive NASA technical paper “Integrated Extravehicular Activity Human Research and Testing Plan” (NASA/TP-2019-220232). The impact of using the exploration atmosphere (8.2 psi/34% O2) on various physiological systems has been previously evaluated and summarized in an evidence report. No physiological concerns have been identified, however, the effects of such as atmosphere on the development of SANS is unknown. As part of HRP’s new strategy, that question will be addressed in a future study that will combine head-down tilt bedrest with exposure to the exploration atmosphere. This planned study is captured in the SANS science strategy, and the former gap ExAtm1 has been merged into the new gap SANS-201.
Inactive Documentation:
No Inactive Documentation Available
Risk Ratings and Dispositions per Design Reference Mission (DRM) Category
DRM CategoriesMission
OperationsLong-Term Health
LxCRisk Disposition *LxCRisk Disposition *
Low Earth Orbit6 months3x3Requires Mitigation/Data3x2Requires Mitigation/Data
1 year3x3Requires Mitigation/Data3x2Requires Mitigation/Data
Deep Space Sortie1 month3x2Accepted with Monitoring1x1Accepted
Lunar Visit/
1 year3x3Requires Mitigation/Data3x2Requires Mitigation/Data
Deep Space
1 year3x3Requires Mitigation/Data3x2Requires Mitigation/Data
Planetary3 years3x3Requires Mitigation/Data3x2Requires Mitigation/Data
Note: LxC is the likelihood and consequence rating. The information above was last approved by the Human System Risk Board in 10/2016.
Risk Statement
Given that future human exploration missions will require a robust, flexible EVA architecture not provided with existing approved operational prebreathe protocols, but that might be met by the use of a reduced pressure cabin atmosphere, there is a possibility that this staged atmosphere could result in compromised health and performance to the crewmember due to exposure to mild hypobaric hypoxia.
Gaps (6)