Figure 1.
GCR organ dose characterization at average solar minimum.
(A) The attenuation of annual GCR organ averaged doses versus depth of aluminum shielding for deep space, the martian surface, and for combined GCR and trapped protons in the ISS orbit. Calculations are for males absorbed dose (D) (mGy), solid cancer and leukemia risks (H) (mSv), and non-cancer effects (G) (mGy-Eq). Calculations on the martian surface consider its atmosphere with an 18 g/cm2 CO2 vertical height.
Figure 2.
Distribution of %REID for solid cancer for particles represented by Z*2/β2 for deep space, martian surface and ISS orbit for 20 g/cm2 shield.
The full GCR spectrum that traverse astronauts in deep space are more biologically damaging compared to the higher energy GCR that occur in low Earth orbit.
Figure 3.
Estimates of the GCR organ doses over recent solar cycles at 0 and 20/cm2 of aluminum shielding (left axis) and the log of the 100 MeV integral proton fluence, which was shown to be a useful predictor of SPE organ doses after considering their variable energy spectra (11) (right axis).
Figure 4.
Estimates of tissue specific %REIC, %PC for incidence and death and %REIC and %REID for 940-d Mars mission with average solar minimum conditions.
(A) Values are for an average 45-y female never smokers and (B) for an average 45-y male never smokers. Calculations assume 20 g/cm2 and 10 g/cm2 aluminum shielding for transit and martian surface, respectively. PC estimations are for 20 years post mission. All point assessments are bracketed by 95% confidence intervals.
Table 1.
Lifetime risks for the 940
Figure 5.
Comparison of %REID from cancer and circulatory diseases combined for several space exploration missions.
(A) Estimates are shown for 45-y old female and (B) male never-smokers. Calculations assume 20 g/cm2 and 10 g/cm2 aluminum shielding for transit vehicle and martian surface habitat, respectively. Error bars reflect the 95% confidence intervals.
Table 2.
Demographic Specific Solar Minimum Safe Days in deep space, which are defined as the maximum number of days with 95% CL to be below the NASA 3% REID limit for males and females at different ages at exposure, aE.