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On its 60th birthday, NASA announced some seriously ambitious goals. Not only does the agency want to make its way back to the moon in 10 years, but they also want to hit up Mars in 20. But just because the space agency says they’re ready to launch people to the Red Planet, it doesn’t mean humans are all that capable of the venture.
A new study published in PNAS raises red flags about the health impact of being in space for a prolonged period of time, such as a voyage to Mars. Let’s just say, the findings may make you reconsider signing up for any upcoming missions.
To test the biological effects of deep space radiation, researchers subjected the small intestines of mice to a bombardment of galactic cosmic radiation similar to what astronauts receive in deep space. The mice exposed to heavy ions were then compared with those exposed to gamma rays (which have similar levels of radiation as X-rays) and to a third unexposed group. They found radiation could cause significant damage to the gastrointestinal tissue, leading to long-term functional alterations and a high risk of developing tumors in the stomach and colon.
The intestinal cells of mice exposed to heavy ions also did not adequately absorb nutrients. Furthermore, ion radiation caused DNA damage that affected the migration of cells needed to replace the intestinal lining for healthy GI functioning. The damage appears to be permanent.
“We have documented the effects of deep space radiation on some vital organs, but we believe that similar damage responses may occur in many organs,” explained senior investigator Kamal Datta in a statement. “It is important to understand these effects in advance so we can do everything we can to protect our future space travelers.”
It builds on previous work that suggests exposure to energetic heavy ions in space – which don't affect us on Earth because of our protective global magnetosphere – could cause damage to brain tissue and accelerate aging.
“Heavy ions such as iron and silicon are damaging because of their greater mass compared to no-mass photons such as X-rays and gamma (g)-rays prevalent on Earth, as well as low mass protons in outer space,” said Datta.
An earlier study estimated that a single trip to Mars would expose astronauts to at least 60 percent of the total dose limit currently recommended for their entire career, based on data collected by ExoMars. According to researchers, it is difficult for current shielding technology to protect astronauts from the adverse effects of heavy ion radiation. There may be a way to use medicine in the future to counter these effects, but as of now, one hasn’t been developed.
“While short trips, like the times astronauts traveled to the Moon, may not expose them to this level of damage, the real concern is lasting injury from a long trip, such as a Mars or other deep space missions which would be much longer,” said Datta.
