C) This includes choosing an initial site for a base/colony in an area of lower natural radiation; at a lower elevation, for instance. Also, hilly or mountainous terrain is preferable over a plain, as the hills etc will provide additional shielding against radiation coming from the sky. Nestling against a cliff or even under an overhang will maximise this, but radiation is not the only environmental danger!
Quote from: CuddlyRocket on 06/18/2016 12:24 pmC) This includes choosing an initial site for a base/colony in an area of lower natural radiation; at a lower elevation, for instance. Also, hilly or mountainous terrain is preferable over a plain, as the hills etc will provide additional shielding against radiation coming from the sky. Nestling against a cliff or even under an overhang will maximise this, but radiation is not the only environmental danger!Another reason I like various Vallis Marinaris potential base sites. Possibility of far less than 180 degree exposure to GCR sky, etc because of surrounding smaller side canyon walls raising the horizon angle. It's over 2Km below the 0 Mars datum so added atmospheric protection too. Knockout factor could be lack of subsurface ice.
Quote from: philw1776 on 06/18/2016 02:48 pmQuote from: CuddlyRocket on 06/18/2016 12:24 pmC) This includes choosing an initial site for a base/colony in an area of lower natural radiation; at a lower elevation, for instance. Also, hilly or mountainous terrain is preferable over a plain, as the hills etc will provide additional shielding against radiation coming from the sky. Nestling against a cliff or even under an overhang will maximise this, but radiation is not the only environmental danger!Another reason I like various Vallis Marinaris potential base sites. Possibility of far less than 180 degree exposure to GCR sky, etc because of surrounding smaller side canyon walls raising the horizon angle. It's over 2Km below the 0 Mars datum so added atmospheric protection too. Knockout factor could be lack of subsurface ice.Another possible knockout factor in re valley floors in general, throughout the Vallis Marineris complex, is that the canyon floors tend to be covered by debris that has come down off the canyon walls over billions of years. It's unknown how deep this talus/debris layer is, and how well consolidated it is.In other words, a lot of the canyon floors may be covered by tens of meters of loose, unconsolidated dust, rocks and soil. Thermal inertia as seen by MO indicates a dust cover over these areas -- but it can't give a lot of feel for how deep that layer is.
Your housing doesn't just have to handle average it has to handle a Coronal Mass Ejection event from the Sun that hits it full on, as nothing else will.
Keep in mind that Mar's sea level atmospheric pressure is 1/169 that of Earth. Earth's atmosphere is about 1030Kg/m^2 of protection over the surface.
because the lander/return vehicle will be sat on the surface for considerable periods - radiation is damaging to the vehicle’s structure, especially electronics, and it may have to act as a habitat for periods, for example in an emergency.
establish both the amount and nature of the radiation environment before designing any protection. There’s a big difference between protecting from galactic cosmic rays and UV, for instance. SpaceX should send the appropriate measuring equipment on its proposed Red Dragon missions
C) This includes choosing an initial site for a base/colony in an area of lower natural radiation; at a lower elevation, for instance. Also, hilly or mountainous terrain is preferable over a plain, as the hills etc will provide additional shielding against radiation coming from the sky. Nestling against a cliff or even under an overhang will maximise this, but radiation is not the only environmental danger!A site with easily accessible resources utilisable as radiation shielding – regolith, rock, even ice – is desirable. If you propose burying any habitat, then probably best not site your base/colony on solid rock.
the Curiosity rover ... seems to have discovered that the surface is itself radioactive (probably due to eons of GCR bombardment), but how radioactive and what type of radioactivity? One may need to be cautious about piling radioactive regolith against the skin of a habitat!
Long term animal studies on 'synthetic' (aka particle accelerated protons and other nuclei with a similar energy profile) are being done right now. Indications are that GCR is worse then has been previously suspected, contrary to popular belief NASA's past estimates were optimistic, it is reality which is pessimistic.
And there's also drug countermeasures.For acute doses, Amifostine has been shown to reduce carcinogenic effects of radiation, including a reduction in resultant DNA damage. In this study, for instance, Amifostine reduced odds of developing tumors in mice exposed to radiation to just 1/3 the odds of mice not receiving Amifostine: http://www.ncbi.nlm.nih.gov/pubmed/6093999Chronic, low doses of radiation are incredibly hard to study since the statistical power is so low, thus we don't know if Amifostine helps for that. But for the very occasional extremely powerful solar flare that occurs with radiation coming in from the zenith, then Amifostine would provide a nice countermeasure.