According to new results from NASA’s Curiosity rover, the risk of radiation will not prevent the long-term mission to Mars from going ahead.
The planned mission involves a 180-day cruise to Mars, followed by a 500-day stay and then a 180-day return journey to Earth. This will apparently expose the astronauts to a cumulative radiation dose of approximately 1.01 sieverts. Normally the European Space Agency limits astronauts radiation dose to 1 sievert and that is a total for their entire career! Just this limit is associated with a 5% increase in lifetime fatal cancer risk.
The Principal Director of Curiosity’s Radiation Assessment Detector (RAD) and lead author of this study, Don Hassler said: “It’s certainly a manageable number.”
NASA’s current standard on radiation levels mean that 1 sievert would be a violation. RAD’s data show that astronauts exploring the Martian surface would accumulate about 0.64 millisieverts of radiation per day. The dose rate is nearly three times greater during the journey to Mars, at 1.84 millisieverts per day. But Hassler explains that these guidelines were created for low-Earth orbit and with these long-distance trips planned, adjustments may be needed in the future.
“NASA is working with the National Academies’ Institute of Medicine to evaluate what limits would be appropriate for a deep-space mission, such as a mission to Mars,” Hassler told SPACE.com. “So that’s an exciting activity.”
The measurements taken by Curiosity should be helpful to NASA when planning this mission to Mars. So far the results have suggested that microbial life is unlikely to exist on the Red Planet’s surface but the plan for future missions is to dig beneath the surface.