A few conspiracy theorists who claim we never actually went to the Moon mention the inability of the space suits and craft of the time to hold out the cosmic radiation. Do they have enough time to gauge whether a human could survive a trip to Mars and back? Considering Mars no longer has a magnetic field (why it lost its atmosphere – I watch too much NOVA), getting to Mars will not provide a safe haven.

Maybe I am glad I didn’t become an astronaut?

Was Einstein Wrong about Space Travel? | Science Blog

While the astronaut twin is hurtling through space, Cucinotta explains, his chromosomes are exposed to penetrating cosmic rays. This can damage his telomeres—little molecular “caps” on the ends of his DNA. Here on Earth, the loss of telomeres has been linked to aging.

So far, the risk hasn’t been a major concern: The effect on shuttle and space station astronauts, if any, would be very small. These astronauts orbit inside of Earth’s protective magnetic field, which deflects most cosmic rays.

But by 2018, NASA plans to send humans outside of that protective bubble to return to the moon and eventually travel to Mars. Astronauts on those missions could be exposed to cosmic rays for weeks or months at a time. Naturally, NASA is keen to find out whether or not the danger of “radiation aging” really exists, and if so, how to handle it.