Despite the financial hurdles likely to prevent humans from going to Mars anytime soon, scientists still constantly brainstorm the challenges of getting to the Red Planet safely. In addition to studying the need for long-term healthy food options for such a journey, scientists also analyze data from NASA’s Curiosity rover to try and anticipate other potential complexities of such a mission.
The latest one? Radiation.
About a year ago, as the Curiosity rover made its way to Mars, readings from its Radiation Assessment Detector indicated that astronauts would be exposed to 554-770 millisieverts of radiation on the journey. What does that mean, exactly? Well, most people are exposed to roughly 6.2 millisieverts of radiation a year. Taking a trip to Mars would be akin to getting a CT scan “once every five days,” according to the Cary Zeitlin, lead scientist for the Martian Radiation Environment Experiment. What that means in terms of tangible effects is still unknown. On the bright side, Martians probably wouldn’t find radiation-caused mutations all that strange, but I think it’s safe to say that we don’t want to find out.
In a 2010 report on space radiation, NASA concluded that with heavy shielding, an average 35-year-old could spend anywhere from 88-186 days in deep space without incurring more than a 3% increased risk of cancer. For non-smokers, that number is a bit higher; the number also goes up as age increases. The problem is that astronauts going to Mars have to make at least one trip, and probably two, as well as spend time on the Red Planet.
So the question becomes what to do about the penetrating galactic cosmic rays, given that shielding capable of blocking the radiation would have to be a couple meters thick, making it too heavy for a spacecraft. The answer is right out of science fiction, as so many solutions are.
At the UK Ruther Appleton Laboratory (RAL), scientists have been working for many years on a lightweight system to protect astronauts from radiation. They’re also working with scientists in America on a new spacecraft that could one day bring astronauts safely to Mars. The lead researcher for RAL’s deflector shield project, Ruth Bamford, praises Star Trek’s “great ideas” that helped inspire the “mini magnetosphere” design they’ve come up with. Basically, the idea is to surround the spacecraft with an environment similar to Earth’s magnetic field so that astronauts can be protected in the same way humans are here on Earth. Scientists have learned that if they put “a magnetic field around an object in a flowing plasma,” they can create an electric field strong and constant enough to deflect the radiation.
Bamford is confident about the design, as it has been successfully tested on a model inside a fusion reactor. “Perhaps we should call down to Scotty.”