Gap CNS - 7: What are the best shielding approaches to protect against CNS risks, and are shielding approaches for CNS and cancer risks synergistic?
Last Published:  07/30/20 02:45:13 PM (Central)
Responsible Element: Space Radiation (SR)
Status: Closed
Closure Rationale
Domain transferred to NASA's Advanced Exploration Systems - Space Radiation Analysis Group.
Closure Documentation:
No Closure Documentation Available
Description


Initial State of Gap:

The development of new biological understanding of CNS risks will determine whether strategies for shielding protection for CNS are distinct from shielding approaches to other radiation risks.  Preliminary assessments suggest HZE nuclei with Z>6 or neutrons may be a higher relative concern for CNS than for other risks, and may place more emphasis on shielding these components. In particular, several CNS endpoints have shown extreme sensitivity to Ti ions with emerging results suggesting unique deficits for He as well. Within mission relevant exposures, CNS response vs dose also exhibits a unique situation where small doses and large doses have shown a decreased risk of adverse outcome while intermediate doses have shown an increased risk. New data on RBE will inform shield design requirements in units of mGy-eq to update shield requirements for comparison with Cancer (units of mSv).

 

Approach:

The development of new biological understanding of CNS responses to space radiation will determine whether strategies for shielding protection for CNS are distinct from shielding approaches used to mitigate other radiation risks. Systems biology approaches will be used, if required, to interpolate radiation quality and dose-rate effects for CNS adverse outcome measures. Shield assessments can then include strategies to shield for hyper sensitive particle types (e.g., Z=22 Titanium; Z=2 Helium) as well as strategies to assess and design for U-shaped dose vs. response curves.  Shield specifications will be compared across all risk areas to optimize shielding for minimum mass and maximum risk mitigation.

 

Interim Steps:  

  • Determine whether there are radiation quality dependent impacts on CNS irradiation reactions that may inform shielding design
  • Identify whether radiation quality differentially impacts CNS and cancer risks
  • Shielding assessment using indexed biomarker panels to monitor adverse CNS outcomes
  • Systems biology analysis to interpolate/convolve radiation quality, dose-rate effects, individual factors with CNS adverse outcomes

 

Target for Closure
  • Utilize systems biology model interpolation of heavy ion particle type, dose-rates and crew factors to identify CNS-specific radiation exposure signatures and biomarkers of adverse outcome pathways.
  • Determine the relative contributions or weighting to adverse outcomes elicited by GCR components.
  • Evaluate dose response curves utilizing available RBE data and refine strategies based on "U" shaped responses in mGy-eq. for mission relevant CNS decrements.
  • Validate complex exposure predictions with GCR simulations.
  • Compare cancer shielding requirements with CNS shielding requirements/strategies and provide cross-risk recommendation to designers.
Mappings
Risk Risk of Acute (In-flight) and Late Central Nervous System Effects from Radiation Exposure
You are here! Gap CNS - 7: What are the best shielding approaches to protect against CNS risks, and are shielding approaches for CNS and cancer risks synergistic?
Completed
Planned-Funded
Terminated

Documentation:
No Documentation Available