An Aerospace Engineering Guide to Space Radiation: Science and Strategies

Ionizing particle radiation is one of the central concerns for the future of long-term, human spaceflight beyond low Earth orbit (LEO). That radiation is made up of a diverse group of particles, each with its own continuous energy spectrum, which makes the development of a catch-all passive radiation shield prohibitively massive. Furthermore, uncertainties in how the particles of interest affect the body over long periods of time, especially at the energies that they are found in space, obfuscate the degree to which astronauts must be protected in order to remain safe. Ultimately, the space radiation environment can potentially put astronauts at risk of several significant health problems, including cancer, cardiovascular disease, and cataracts, which not only jeopardize astronauts' quality of life, but can also potentially jeopardize the missions themselves. Put together, these factors pose a unique challenge for space habitat designers: developing a comprehensive, viable radiation protection strategy for astronauts during long-term missions beyond LEO. The purpose of this article is to discuss the science of space radiation exposure and the potential strategies for mitigating it. Special emphasis is placed on the advantages, disadvantages, and engineering feasibility of each solution. This analysis is intended to act as a starting point of reference for aerospace and systems engineers tasked with keeping astronauts alive and healthy in extraterrestrial environments that are characterized by space radiation.