We are not going to Mars for a while

Discussed in Discover more than a year ago but ignored by Stephen Hawking, it’s clear that cosmic rays will keep us from the Red Planet for the foreseeable future, Preznit Bush and his Martian pony not withstanding. The National Research Council says we ain’t making manned six-month space trips until NASA figures out how to protect humans from interplanetary cosmic rays and that NASA isn’t doing that right now.

The Earth’s bulk, atmosphere and magnetic field protect life from the solar radiation and the cosmic rays that travel through space. Astronauts have just a thin layer of shielding.

(Astronaut James) Van Hoften knows from personal experience.

“My introduction to space radiation came first-hand as a crew member aboard the Space Shuttle Challenger in April 1984. ‘What the heck was that?’ I blurted out after seeing what looked like a white laser passing quickly through my eyes,” van Hoften wrote in the introduction to the report.

“‘Oh, that's just cosmic rays,’ said Pinky Nelson, my spacewalking partner and space physicist. The thought of extremely high-energy particles originating from a distant cosmic event passing easily through the space shuttle and subsequently through my head made me think that this cannot be all that healthy. The truth of the matter is that it is not.”

No, it isn’t. Six months going out and another six months back to Mars is a lot more than a week in the space shuttle.

Half-jokingly, Hoften said NASA should send older astronauts, since they will likely not live long enough before the full effects of cosmic-ray damage become apparent.