As NASA plans to return to the Moon, and eventually send astronauts to Mars, mission planners will have to grapple with a fact of life in deep space beyond the protective ward of Earth’s geomagnetic field — constant bombardment by cosmic radiation. Learning how humans will respond to chronically elevated but not immediately lethal radiation environments is a necessity for scientists hoping to protect or heal future astronauts from their passage through the cosmic radiation bath on their way to and from the Red Planet.
