Effects of Space Radiation on Humans and Electronics

The space radiation environment that presents a hazard to humans and electronics is complex, comprised of galactic cosmic rays, solar energetic particles, and trapped belt radiation. The range of ion species and energies range primarily from protons up to nickel with energies up to several TeV per nucleon. Particle fluences are great enough to pose risks to crew and electronics over extended missions, both from long-term exposure to GCR as well as acute effects from unshielded solar particle events. Long-term health effects considered by NASA include radiogenic cancers, cognitive impairment, detrimental heart function. Current calculations indicate that a three-year mission Mars will have integrated effective doses that exceed the career limits for crew, based upon a 3% increase in REID with a 95% confidence level. Effects to electronics from exposure include single-effect upsets, latch-ups, transients, burnouts, and gate ruptures, all of which are a function of the linear energy transfer of the ions incident on the device. A description of the effects to crew and electronics will be presented, along with a discussion of the current state of space radiation transport modeling and the nuclear data needs to further reduce the uncertainties in those model calculations.