Outer space

Apollo astronauts reveal heart risks of space travel

NASA astronauts on the Apollo missions to the moon, flown in the 1960s and 1970s, are the only humans to have flown beyond the protective magnetic shielding of Earth -- and a new study shows that exposure to deep-space radiation may have taken a toll on their hearts.

The research compared Apollo astronauts' fates with those of unflown astronauts -- who never made it into space -- and those who lingered in low-Earth orbit, and found an increased level of death from cardiovascular problems in the deep-space adventurers. In a study with mice, the researchers also found a long-term effect on heart health from radiation exposure.