tomcat wrote:
Brad, as I once mentioned, the Astronauts on the Moon are not going to
dance around the uranium mine in the nude. You don't do that on Alien
Planets, Planetoids, and Moons.

Those Astronauts will be protected by their spacesuits, by their
vehicles, by their habitats, and deep underground tunnels, rooms, and
quarters. They might even bring some radiation protecting Beta Lights
with them too.
Those moonsuits in places represented as little as 0.5 g/cm2 worth of
shielding mass, and that's much less than a tenth of an inch of
aluminum, and otherwise at best being worth 1 g/cm2 or 0.156" of
aluminum. That's not going to buy your DNA frail butt more than 1.5%
reduction in hard-X-rays and perhaps not a 0.15% reduction in gamma. I
suppose wearing a lead cup might bring their testicles into the realm
of having as much a 5 g/cm2 worth of shield that's worth a good 12%
reduction from hard-X-rays and perhaps worth another good 1% reduction
in gamma.

As I've informed you that I hadn't previously said anything that was
close to 13 rads/hr, at least not as pertaining space travels external
to the magnetosphere, whereas if our physically dark and nasty moon is
not evolved and you've headed yourself away from our sun, it should
become much less than that amount of dosage unless your butt is getting
nailed by a bad solar/cosmic event, in which case it really doesn't
matter how low the average dosage level is because, from a singular bad
event you are either dead or soon going to become dead unless you've
got one hell of a massive spacecraft protecting your frail DNA. Having
an extremely well shielded cash of your sub-frozen bone marrow and a
few of those spare stem-cells available might save the day, whereas
otherwise don't plan upon coming home unless you're in a body-bag.

I had actually said many times that the Van Allen belt environment that
can offer an average of 23 rads/hr while shielded by 2g/cm2 (that's
roughly 5/16" worth of 5086 aluminum) is derived from a sufficiently
hard-science matter of fact, and as such is less TBI worthy than being
situated on the gamma and hard-X-ray moon of ours while using that same
2 g/cm2 worth of shielding, and that's only recently become a matter of
scientific fact because our moon having been recorded as being much
worse off than what the well known bad parts of our Van Allen expanse
has to offer. Therefore, I wouldn't expect a moonsuit dosage of
anything less than 50 rads/hr if it's a relatively passive solar day,
and otherwise we're talking several hundreds of rads/hr if it's a
somewhat more active solar day, with a truly bad solar day offering
several thousands of rads/hr that have frequently gone entirely off
scale upon having saturated the various detection instruments we've got
situated external to our magnetosphere's Van Allen expanse. However,
if our sun goes into a nearly passive mode is also when the most lethal
dosage of cosmic influx gets through. So, if you are out and about as
moonsuit walking on that physically dark and nasty moon of ours, you
are sort of in a no-win situation, especially getting double-IR and
unavoidably gamma plus extra X-ray TBI dosage worthy by day.

While on the moon, unless you're situated within a very small diameter
but otherwise deep crater, you're unavoidably surrounded by at least a
km radius of absolutely nasty badlands, therefore count on 3.14e6 m2
worth of whatever's locally radioactive and otherwise being unavoidably
reactive to the cosmic and solar influx as being of contributing
factors to the demise of your frail DNA. Since there's supposedly such
a slight amount of surface atmosphere to work with, that's regardless
still unfortunately capable of being nicely reactive (especially
reactive if there's heavy elements such a Rn222 are available), and
thereby affording hardly any measurable attenuation of whatever is
coming off each and every square meter of that naked moon, whereas such
each m2 doesn't actually have to represent all that much individual
gamma and hard-X-ray dosage. A few local millirads/m2/hr times 3.14e6
and your DNA is going to be seriously fried from all directions, as
well as from the inside out as that local and whatever influx gamma
interacts with the bone and bone marrow of your own body. And, since
it's of an environment that's no longer representing itself as a given
point source of radiation, but that of a surrounding terrain of
radioactive and otherwise unavoidably reactive badlands, as such
there's nothing much you can do to save your soul, other than getting
the hell out of there as soon as possible or going deep underground,
because it's simply not practical much less affordable or even
technically as of yet doable to deliver a necessary amount of suitable
shield material to that moon of ours, that is without such an effort
creating yet another delivery impact crater.

Of course, if we had the efficient 'tomcat' VTOL spaceplane with it's
nifty million pound payload capability, as such we could obviously go
to/from that nasty sucker of a moon as often as we'd like and as
quickly as perhaps managing such within 7 day round trips, spending as
little as an hour on the earthshine illuminated deck where the local
reactive environment is getting least impacted by the solar influx. Of
course, just having to nearby orbit that nasty moon of ours in simply
not going to represent a safe margin of crew and passender safety,
fudge factor or that of any measurable attenuation factor from being
fully exposed to that nasty lunar surface that's more than a wee bit
radioactive as well as remaining unavoidably reactive for as far as
that spaceplane can see, whereas we are talking about a 600 km or
better radius, of at least getting nailed by 1.13e12 m2 of exposure,
that which the extremely large but otherwise relatively low density
spaceplane has to contend with. Thus how much shield mass and/or
volume of whatever's similar to water is that of our 'tomcat'
spaceplane planning upon accommodating for benefiting that of the crew
and passenders, or is having a one-way ticket to ride and certain death
their one and only viable option?

Venus on the other hand offers whatever DNA considerably less of the
nasty solar and cosmic influx as getting through to that geothermally
toasty surface environment, therefore at least the likes of such lethal
cosmic and solar radiation that's seriously bad for one's DNA is simply
less than right here on mother Earth.
-
Brad Guth