Long-Haul Space Flights Might Damage Astronauts’ Brains

This warning is based on a study involving rats, but researchers think it could apply to humans as well

Photo: DAVID DUCROS/Science Photo Library/Corbis

With long-haul trips to Mars an ever-more realistic possibility, scientists are thinking about what the impact of months-long space flight will be—both on astronauts' behavior and their physical health. Space is full of radiation, and there's clearly some risk associated with spending months speeding through that sort of environment. According to one new study, long-term exposure to space might damage proteins in the brain, reports Adrienne LaFrance, at the Atlantic. The study looked only at the brains of rats, but found that exposure to high-energy particles could lead to several cognitive defects, including memory problems and slower reaction times. 

Some of their findings, however, are perplexing. LaFrance writes:

But the strange thing scientists found is that deep-space conditions don't affect everyone the same way. About half of the rats tested emerged from the test entirely unaffected. The others began showing symptoms about seven weeks after exposure to space-like conditions. And once impairments appeared, they never went away. (Some rats showed improvement over time, however, raising the question of whether recovery is possible.)

These findings held true even at very low radiation exposure levels, RedOrbit adds

Since the study did not examine human subjects, the researchers can't say whether, or how, their results apply to astronauts. If there is some connection, though, it might be possible to identify biological markers for susceptibility to these types of problems, LaFrance reports. Then, this physiological trait could be added to the already lengthy list of characteristics—from specific heights to eyesight requirements—that astronaut applicants must meet in order to be considered for the position. 

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