Curiosity instrument confirms expectation of major exposures
Astronauts making the journey to and from Mars would face many new and uncertain dangers. Fortunately, the Mars rover Curiosity has reduced uncertainty about one of them: radiation exposure.
Measurements of radiation reaching the shielded interior of the spacecraft that carried Curiosity to Mars indicate that an astronaut on a yearlong round-trip would be exposed to around two-thirds of the career radiation limit that some space agencies set. Any time spent on the planet and outside the spacecraft would add more exposure.
The radiation dose they calculated was 0.66 sieverts, researchers report in the May 31 Science; the agencies’ limit for astronauts is 1 sievert.
On Earth, a 1-sievert dose increases cancer risk by about 5 percent. Scientists don’t know whether space radiation would have similar effects.