Lunar radiation risk assessment and shielding design for ionizing space radiation

NASA is now focused on the agency's vision for space exploration encompassing a broad range of human and robotic missions including missions to Moon, Mars and beyond. As a result, there is a focus on long duration space missions. NASA is committed to the safety of the missions and the crew, and there is an overwhelming emphasis on the reliability issues for space missions and the habitat. The cost effective design of the spacecraft demands a very stringent requirement on the optimization process. Exposure from the hazards of severe space radiation in deep space and/or long duration missions is a critical design constraint and a potential 'show stopper.' Thus, protection from the hazards of severe space radiation is of paramount importance to the agency's vision. It is envisioned to have long duration human presence on the Moon for deep space exploration. Tlie exposures from ionizing radiation - galactic cosmic radiation and solar particle events - and optimized shield design for a short-term and a long-term mission to Moon have been investigated. It is found that the technology of today is adequate for short-term safe human missions to Moon, and revolutionary technologies need to be developed for long duration Moon missions and/or deep space missions. The study will provide a guideline for radiation exposure and protection for long duration missions and career astronauts and their safety(12).