Curiosity measures radiation dose for Martian travel

Nature : The Mars Science Laboratory mission that landed Curiosity on Mars also used the rover to monitor radiation exposure during the trip to the planet. The vehicle that carried the rover from Earth to Mars was protected by radiation shielding equivalent to that used on human space flights. Curiosity monitored its exposure over the 253-day trip and found that the level of exposure was higher than NASA currently permits for its astronauts. Exposure limits for people who are 30â60 years old and have never smoked have been set at 0.8 to 1.2 sieverts for men and 0.6 to 1 sievert for women. A 1-sievert exposure is associated with roughly a 5% increase in the risk of developing a fatal cancer. Models suggest that additional conventional shielding materials would reduce the radiation exposure from the solar wind but not that from extra-solar cosmic rays. NASA, which has already begun testing new materials to shield astronauts and equipment from the latter, is focusing on hydrogenated materials because hydrogen doesn’t break into radioactive particles when struck by high-energy particles.