Space radiation is one of the primary environmental hazards associated with space flight.
Crew members are subjected to greater amounts of natural radiation in space than they receive on Earth, exposing them to both immediate and long-term risks. Trapped belts of energetic particles, found in the Earth's magnetic field, consist predominantly of protons and electrons. A solar particle event, which sometimes accompanies CME's, may be the most potent space radiation hazard. High dose radiation exposure can lead to acute radiation sickness and has the potential to cause late effects such as cancer and cataracts in humans. Space radiation can differ from gamma rays and X-rays in terms of energy absorption and ionization pattern.