Astronauts Could Survive Mars Radiation for Long Stretches

Radiation Dose Astronauts Mars

Astronauts could endure a long-term, roundtrip Mars mission without receiving a worryingly high radiation dose, new results from NASA's Mars rover Curiosity suggest.

A mission consisting of a 180-day outbound cruise, a 600-day stay on Mars and another 180-day flight back to Earth would expose an astronaut to a total radiation dose of about 1.1 sieverts (units of radiation) if it launched now, according to measurements by Curiosity's Radiation Assessment Detector instrument, or RAD.

That's a pretty manageable number, researchers said.

"The rough ballpark average for an astronaut career limit is on the order of a sievert," RAD principal investigator Don Hassler, of the Southwest Research Institute in Boulder, Colo., said in a presentation here Monday (Dec. 3) at the annual fall meeting of the American Geophysical Union. [Video: Curiosity Takes First Cosmic Ray Sample on Surface]

"NASA has a much more complicated determination for that, but ESA [the European Space Agency], for example, generally uses 1 sievert for that number," he added.

RAD has found radiation levels on the Martian surface to be comparable to those experienced by astronauts in low-Earth orbit. A person ambling around the Red Planet would receive an average dose of about 0.7 millisieverts per day, while astronauts aboard the International Space Station experience an average daily dose between 0.4 and 1.0 millisieverts, Hassler said.

RAD's measurements show that Mars' atmosphere — though just 1 percent as thick as that of Earth — provides a significant amount of protection from the fast-moving particles streaking through our galaxy ( via ).

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