Space Radiation Devastated the Lives of Apollo Astronaut
observer.com
observer.com
Tissues such as the spleen and the lungs are not considered structural because, while they certainly have a physical configuration that is important, their function is distributed identically, or nearly identically, throughout their structure.
If radiation affects one part of a non-structural tissue, it's function is relatively easily transferred to another area.
This is not true of the cardiovascular system; the function of the aorta, for example, cannot be accomplished by a capillary in the leg.
Radiation beyond the magnetosphere can be understood as mainly a point injury. When the highly-accelerated nucleus of a heavy element, for example, passes through a tissue, it causes local tissue damage. This is more important when the tissue is structural, and even more important when that tissue has a limited capacity for repair.
The Apollo astronauts were only beyond the magnetosphere for two weeks or less. Travel to Mars, or habitation on the moon, will both require far greater radiation exposures.
Shielding from highly-accelerated nuclei is currently impossible because they create secondary radiation in any shielding material that is far worse than the original problem.
Long-duration human space flight beyond the magnetosphere is therefore impossible with current technology, despite the hype. We must develop either strong magnetic shielding or genetic modifications to improve radiation resistance before traveling to Mars, otherwise we will arrive with impaired cognition and other infirmities.
Sorry to be the bearer of bad news.
The sun is a very predictable source so you can do a lot to shape the field such as placing it on a boom closer to the sun.
Also of note Mars is significantly further from the sun which significantly reduces total exposure.
You see the basic problem with magnetic shielding is radiation still following field lines. (see: Aurora Borealis/Aurora Australis).
This presents three options. You can add shielding for the end cap including for example unspent fuel. You can make your living space a donut surrounding the device. Or put it out on a boom. If your going to use a boom you will be protected from cosmic charged partials as long as your close to the device and inside the inner circle. But, by placing the boom closer to the sun you gain extra protection from solar charged particles. Thus reducing minimum necessary field strength.
Would that lead to human adaptations that could survive in more radiation hostile environments?
I don't think there's much a living being can do to become more resistant to radiations; the most effective trick seems to be being small.
Look what we've managed with dogs in just a couple millennia.
Evolution is too slow. We must speed it up.
There are tons of other correlations that can add to it. E.g. astronauts are hand picked group that often gone through years of specialized training.
Edit: There are different subgroups in the article, all of them are small. I mentioned "Deep space refers to the frontier beyond Earth’s protective magnetosphere and atmosphere where only 24 humans in history—all Apollo astronauts, have ever travelled."
> The rate among astronauts who never flew is 9%. Among low-Earth orbiting astronauts, its 11%. For the men who travelled to the Moon, a staggering 43%
E.g. Pete died from motorcycle accident at age 69: https://en.wikipedia.org/wiki/Pete_Conrad
> The group of all flight astronauts was comprised of 5 females and 37 males, of which the LEO astronaut subgroup contained 5 females and 30 males and the Apollo lunar astronaut subgroup was comprised of 7 males. The non-flight astronauts consisted of 3 females and 32 males.
If I understand this correctly, the data set for Apollo astronauts was even smaller - just 7 people.
I strongly suspect it's a case of this: https://xkcd.com/882/
http://arstechnica.com/science/2016/07/apollo-astronauts-dyi...
Same with the training. Non flight astronauts (and the LEO group) had much lower mortality due to cardiovascular disease than the general population. Apollo group was noticeably higher. I guess the guys who went to the moon could have trained that much more than other astronauts, but they would have decent information about that.
I suppose the incident radiation must have been orders of magnitude above what ordinary people get here on the ground, or a few days in space would not amount to much.
Quote from the abstract:
> To test a possible mechanistic basis for these findings, a secondary purpose was to determine the long-term effects of simulated weightlessness and space-relevant total-body irradiation on vascular responsiveness in mice. The results demonstrate that space-relevant irradiation induces a sustained vascular endothelial cell dysfunction. Such impairment is known to lead to occlusive artery disease, and may be an important risk factor for CVD among astronauts exposed to deep space radiation.
They didn't just do some poor statistics with a low sample size.
So, their findings suggests that low gravity for a 6 month period doesn't affect the health of the mice but the radiation does. Not far off what we already suspected but with a small twist (cancer was probably considered a bigger risk than CVD).
NASA and SpaceX won't ever figure this out though. They will fund some sort of initiative that will waste billions and give lots of researchers jobs for years. It will test billions of small molecules and find something that improves tolerance to radiation by .1% but has toxic side effects.
Edit: Gave medical study citations for both claims and got down votes? There are actually a lot of surprising results in medical literature that are ignored because there's not a lot of money in them and they were discovered with so little effort. The conventional wisdom is: if it didn't cost a billion dollars to develop, it couldn't possibly work.
http://www.ncbi.nlm.nih.gov/pubmed/19914272
It's so bizarre that it won't get followed up. I spend a lot of time digging in pubmed and when I find stuff like this, nobody cares. It's too cheap of a solution and not patentable. It will be forgotten because 95% of people will scoff at the result. It's simply too miraculous to be believed.
Am I reading that wrong? That seems to say that mice that got the pretreatment with C60 were less likely to die of radiation poisoning than controls and there was no observed toxicity. That's a pretty astonishing result. This study even has several further studies that cite it, so it seems that there's some followup going on.