Fig. 3: Radiation research conditions and platforms that are encountered and used in space missions and research.

Artificial radiation sources lack the qualitative and quantitative characteristics of naturally variable sources. Radiation is a continuum of exposure transitioning from the surface of the planet where we are shielded from major aspects of galactic cosmic radiation in deep space. We continue to learn about the biophysical challenges of deep space exploration, a major focus of research for human medical countermeasures in LEO, but now more important as a mission-critical component in upcoming lunar missions that will extend out beyond the Van Allen belts (modified from original source¹¹²).