Acute Risks of Space Radiation

Abstract

The space radiation environment consists of highly charged and energetic particles that include high-energy protons released from the sun during solar particle events (SPEs). SPEs that are above 25–30 mega-electron volts (MeV) can penetrate the shielding on the International Space Station (ISS) and present a major challenge for the National Aeronautics and Space Administration (NASA). During long-term deep space missions, it is anticipated that multiple SPEs will be encountered. Such exposures are a significant radiation hazard to astronauts and spacecraft. Indeed, exposure to SPEs may place astronauts at risk for acute radiation sickness (ARS), prodromal effects, skin damage, hematological/immune deficits, and changes in other body compartments. The timing of symptom onset varies with radiation dose, dose rate, quality, and individual sensitivity.