At least so this news story claims:

https://www.unilad.com/technology/space/mars-declared-unsafe-humans-survive-four-years-356854-20240320

After four years on Mars, radiation exposure will exceed safe levels.
So, it is absolutely impossible for any humans to settle permanently
on Mars and make it their new home.

There are of course two fundamental errors in their logic.

Robert Zubrin would point out that "safe levels" that are established
by standards on Earth involve a very low tolerance for risk, and so
the information in the article only implies that people living on Mars
would have a somewhat greater cancer risk than people on Earth.

That doesn't make Mars uninhabitable any more than, say, Boulder,
Colorado is uninhabitable.

I would point out that while a certain amount of shielding does indeed
make cosmic rays worse, thanks to secondary radiation - something the
article alludes to - still more shielding eventually fixes that.
Otherwise, Earth's atmosphere would make cosmic radiation worse here
than in space.

Mars is a *planet*. So there is plenty of rock available to use for
shielding. I really doubt that people living, say, *75 feet
underground* on Mars will be in any particular danger from radiation,
and it's perfectly possible to use simple mirror systems to take
sunlight from the surface of Mars, and focus it and send it down a
very narrow hole to allow a deep artificial cavern to be well-lit.

On the bottom of the page on my web site

http://www.quadibloc.com/science/spa02.htm

I illustrate such an optical system.

We _can_ settle Mars, even if construction there will be more
expensive than on Earth.

John Savard

On Sat, 23 Mar 2024 22:47:32 -0600, John Savard
<quadibloc@servername.invalid> wrote:

>At least so this news story claims:
>
>https://www.unilad.com/technology/space/mars-declared-unsafe-humans-survive-four-years-356854-20240320
>
>After four years on Mars, radiation exposure will exceed safe levels.
>So, it is absolutely impossible for any humans to settle permanently
>on Mars and make it their new home.
>
>There are of course two fundamental errors in their logic.
>
>Robert Zubrin would point out that "safe levels" that are established
>by standards on Earth involve a very low tolerance for risk, and so
>the information in the article only implies that people living on Mars
>would have a somewhat greater cancer risk than people on Earth.
>
>That doesn't make Mars uninhabitable any more than, say, Boulder,
>Colorado is uninhabitable.
>
>I would point out that while a certain amount of shielding does indeed
>make cosmic rays worse, thanks to secondary radiation - something the
>article alludes to - still more shielding eventually fixes that.
>Otherwise, Earth's atmosphere would make cosmic radiation worse here
>than in space.
>
>Mars is a *planet*. So there is plenty of rock available to use for
>shielding. I really doubt that people living, say, *75 feet
>underground* on Mars will be in any particular danger from radiation,
>and it's perfectly possible to use simple mirror systems to take
>sunlight from the surface of Mars, and focus it and send it down a
>very narrow hole to allow a deep artificial cavern to be well-lit.
>
>On the bottom of the page on my web site
>
>http://www.quadibloc.com/science/spa02.htm
>
>I illustrate such an optical system.
>
>We _can_ settle Mars, even if construction there will be more
>expensive than on Earth.
>
>John Savard

But... why would we? We lack (by a large margin) the knowledge to
survive there without massive amounts of traffic from Earth supplying
resources. And there's no value in being there.

On Sun, 24 Mar 2024 22:21:00 -0600, Chris L Peterson
<clp@alumni.caltech.edu> wrote:

>But... why would we? We lack (by a large margin) the knowledge to
>survive there without massive amounts of traffic from Earth supplying
>resources. And there's no value in being there.

Do we?

I would tend to admit that the amount of traffic from Earth to supply
start-up resources would still be "massive" by current standards, even
if, as seems not unlikely to me, there was the ability to harvest
volatiles from comets for use by a Mars colony.

But if you mean, as I think likely, massive *continuing* traffic from
Earth supplying resources... I disagree. We do lack the knowledge to
have a completely closed cycle on a *small spaceship*, but just build
a large enough colony occupying several acres, stock it with a wide
variety of Earth lifeforms, going heavy on oxygen-generating plants...
reproducing a viable isolated ecosystem surely isn't that hard.

As long as the scale is larger even than that of the failed "Biosphere
II" experiment.

As for value in being there... given that both Russia and China have
nuclear weapons, Earth is claustrophobically small. Humanity,
civilizatiion, and liberty MUST survive under all conditions
whatsoever, and therefore Mars colonization is an imperative, given
that nuclear war, or avoiding it by surrender, or Trump getting
elected in 2024 (avoiding it by a Co-Dominion scenario, or one like in
the "Fatherland" novel) are not impossible.

John Savard

On Mon, 25 Mar 2024 07:24:16 -0600, John Savard
<quadibloc@servername.invalid> wrote:

>On Sun, 24 Mar 2024 22:21:00 -0600, Chris L Peterson
><clp@alumni.caltech.edu> wrote:
>
>>But... why would we? We lack (by a large margin) the knowledge to
>>survive there without massive amounts of traffic from Earth supplying
>>resources. And there's no value in being there.
>
>Do we?
>
>I would tend to admit that the amount of traffic from Earth to supply
>start-up resources would still be "massive" by current standards, even
>if, as seems not unlikely to me, there was the ability to harvest
>volatiles from comets for use by a Mars colony.
>
>But if you mean, as I think likely, massive *continuing* traffic from
>Earth supplying resources... I disagree. We do lack the knowledge to
>have a completely closed cycle on a *small spaceship*, but just build
>a large enough colony occupying several acres, stock it with a wide
>variety of Earth lifeforms, going heavy on oxygen-generating plants...
>reproducing a viable isolated ecosystem surely isn't that hard.
>
>As long as the scale is larger even than that of the failed "Biosphere
>II" experiment.
>
>As for value in being there... given that both Russia and China have
>nuclear weapons, Earth is claustrophobically small. Humanity,
>civilizatiion, and liberty MUST survive under all conditions
>whatsoever, and therefore Mars colonization is an imperative, given
>that nuclear war, or avoiding it by surrender, or Trump getting
>elected in 2024 (avoiding it by a Co-Dominion scenario, or one like in
>the "Fatherland" novel) are not impossible.
>
>John Savard

We can't even sustain ourselves any place on Earth without a steady
stream of imported resources from other parts of the planet. We have
no idea how to create a sustainable closed system.

The survival of our species (and personally, I'm fine with our
extinction... likely we're a failed, evolutionary dead end) does not
remotely rely on getting off the planet. Our increasing inability to
thrive on the planet we evolved on demonstrates the nonsense of
surviving at all on a hostile planet.

Our broken "design" makes it as likely a Trump (or really, the sort of
people who support a Trump) would arise on Mars. And if we look at
history, and our nature, the notion of liberty is rather silly and
quaint. We are a species that has always done best with rigid
societies run by powerful autocrats. Democracy does not appear to work
for us.

On 24/03/2024 04:47, John Savard wrote:
> At least so this news story claims:
>
> https://www.unilad.com/technology/space/mars-declared-unsafe-humans-survive-four-years-356854-20240320
>
> After four years on Mars, radiation exposure will exceed safe levels.

That seems unduly pessimistic.

It might well exceed acceptable risk levels for civilians but the
military wartime emergency dose is remarkably high at lower dose rates.

The Earth was radioactively hotter in the distant past and our DNA
repair mechanisms are really quite good. It will be life shortening to
live in such a high radiation environment but probably not by all that
much compared to all the other dangers and risks of living on Mars.

The normal limit is 200cGy in total per soldier but at dose rates below
15cGy it is acceptable to go for a 100 days. Taken from Appendix J2 ROC.

http://www.roc-heritage.co.uk/uploads/7/6/8/9/7689271/rocjaannexj.pdf

(presumed to be declassified since it is findable on Google)

> So, it is absolutely impossible for any humans to settle permanently
> on Mars and make it their new home.
>
> There are of course two fundamental errors in their logic.
>
> Robert Zubrin would point out that "safe levels" that are established
> by standards on Earth involve a very low tolerance for risk, and so
> the information in the article only implies that people living on Mars
> would have a somewhat greater cancer risk than people on Earth.
>
> That doesn't make Mars uninhabitable any more than, say, Boulder,
> Colorado is uninhabitable.
>
> I would point out that while a certain amount of shielding does indeed
> make cosmic rays worse, thanks to secondary radiation - something the
> article alludes to - still more shielding eventually fixes that.
> Otherwise, Earth's atmosphere would make cosmic radiation worse here
> than in space.
>
> Mars is a *planet*. So there is plenty of rock available to use for
> shielding. I really doubt that people living, say, *75 feet
> underground* on Mars will be in any particular danger from radiation,
> and it's perfectly possible to use simple mirror systems to take
> sunlight from the surface of Mars, and focus it and send it down a
> very narrow hole to allow a deep artificial cavern to be well-lit.
>
> On the bottom of the page on my web site
>
> http://www.quadibloc.com/science/spa02.htm
>
> I illustrate such an optical system.
>
> We _can_ settle Mars, even if construction there will be more
> expensive than on Earth.

It would be ludicrously expensive to settle a colony on Mars. Even doing
it at the lunar pole where there might well be water would be a huge
challenge to keep it supplied. I expect that will happen eventually.

I'm not convinced it will ever be worth the effort of humans visiting
Mars - except possibly for some incredibly high budget reality TV show
along the lines of Big Brother where contestants get to vote who has to
leave the ship next. Unless and until we find something there that our
robotics and AI cannot handle it simply isn't worth it!

Robotics can tolerate a very stressful journey. Humans need to be kept
alive all the way there and all the way back. Soft Mars landings don't
have an exactly stellar record either. The Martian atmosphere is just
thick enough to burn you up on entry but not thick enough to make
parachutes particularly useful.

--
Martin Brown

On Mon, 25 Mar 2024 14:33:09 +0000, Martin Brown
<'''newspam'''@nonad.co.uk> wrote:

>I'm not convinced it will ever be worth the effort of humans visiting
>Mars - except possibly for some incredibly high budget reality TV show
>along the lines of Big Brother where contestants get to vote who has to
>leave the ship next.

That's probably the most likely scenario! Unless we are successful in
eliminating the existence of billionaires (let's hope!), one of the
crazier ones may well blow a ton of money to grandstand a mission to
Mars, with people who don't necessarily have to be kept alive.

On 25/03/2024 16:01, Chris L Peterson wrote:
> On Mon, 25 Mar 2024 14:33:09 +0000, Martin Brown
> <'''newspam'''@nonad.co.uk> wrote:
>
>> I'm not convinced it will ever be worth the effort of humans visiting
>> Mars - except possibly for some incredibly high budget reality TV show
>> along the lines of Big Brother where contestants get to vote who has to
>> leave the ship next.
>
> That's probably the most likely scenario! Unless we are successful in
> eliminating the existence of billionaires (let's hope!), one of the
> crazier ones may well blow a ton of money to grandstand a mission to
> Mars, with people who don't necessarily have to be kept alive.

I fear we are headed for a future of terminally stupid influencers
famous for being on reality TV, endless internet video clickbait with
news and governments controlled and manipulated by a few trillionaires.

Not unlike the dystopian plot of the Dr Who episode "The Long Game"
(but without the malevolent alien holding the human race back).

https://en.wikipedia.org/wiki/The_Long_Game

Entirely self inflicted...

--
Martin Brown

On Mon, 25 Mar 2024 14:33:09 +0000, Martin Brown
<'''newspam'''@nonad.co.uk> wrote:

>Soft Mars landings don't
>have an exactly stellar record either. The Martian atmosphere is just
>thick enough to burn you up on entry but not thick enough to make
>parachutes particularly useful.

In addition, the Martian atmosphere interferes with the operation of
rocket engines, so as to prevent a powered soft landing of the sort
that the LEM made on the Moon. Although, since rockets can be launched
from planets with atmospheres, one would think this was not
insuperable - but in the case of the landing, at least in the early
stages, air is being thrust into the rocket chamber with some force,
and this may be what makes the difference.

John Savard