Sujet : Re: (Off Topic) The Case for Mars by Robert Zubrin
De : jdnicoll (at) *nospam* panix.com (James Nicoll)
Groupes : rec.arts.sf.writtenDate : 05. Jul 2024, 16:23:01
Autres entêtes
Organisation : Public Access Networks Corp.
Message-ID : <v6934l$28s$1@reader1.panix.com>
References : 1 2 3
User-Agent : trn 4.0-test77 (Sep 1, 2010)
In article <
1j2g8jtm8ginije7g3a5jf0b27j4dpsk3i@4ax.com>,
Paul S Person <
psperson@old.netcom.invalid> wrote:
On Fri, 05 Jul 2024 07:12:08 -0600, John Savard
<quadibloc@servername.invalid> wrote:
>
On Thu, 4 Jul 2024 13:04:58 -0000 (UTC), jdnicoll@panix.com (James
Nicoll) wrote:
>
The Case for Mars by Robert Zubrin
>
How America will put people on Mars by 2010!
>
https://jamesdavisnicoll.com/review/so-crystal-clear
>
Technically not SF, at least not intentionally.
>
I did notice how Zubrin handwaved away the question of radiation in
space. Since atronauts are celebrated as heroes, there would be
volunteers willing to put up with an enhanced cancer risk, so no
problem.
>
Just the other day, I was reading about how radiation and microgravity
would shink people's kidneys so much that they couldn't survive a trip
to Mars for that reason alone!
>
I do have an answer for the skeptics - if radiation and microgravity
are problems, then let's not put up with them on a trip to Mars. So,
on my web site, I point out that an O'Neill space habitat could be
improved by enclosing it in a wine-bottle shaped enclosure providing,
if necessary, a couple metres worth of solid rock. And the opening of
the wine bottle could point at a big slab of rock, with mirrors in
between to direct concentrated sunlight to the habitat.
>
Yes, radiation shielding makes cosmic rays worse... but only _up to a
point_. As the existence of life on Earth proves.
>
But if it is required to construct an enormous space habitat with gobs
of lunar material to have a way to safely go to Mars... then it won't
be _inexpensive_ to get there. Nothing at all like Zubrin's optimism,
even if the skeptics who say it can _never_ be done are wrong.
>
You forgot the treadmill, to produce an equivalent of gravity.
>
The first step is to colonize the Moon. And I mean /colonize/, not
just establish a five-person outpost. Domes/caves, hundreds of people,
lots of babies (it's much cheaper to grow the population that way than
to import it from Earth), and, with any luck, in a few decades ships
useable to colonize Mars.
An important question whose answer we don't know is "are humans able
to bear viable kids in low gravity?" No kids, no colony.
Mind you, 1/6th g is different from 1/3 but if there are issues with
this on the Moon, it means we probably need to see if there would be
issues on Mars (on the other hand, if there are no issues on the Moon,
we can be more confident about kids on Mars). The trick might be sorting
out problems that are gravity related from ones that are because of
other factors like the unpleasant qualities of regolith creeping into
the habs.
(As far as I know, Martian regolith is not millions of tiny Aztec
daggers, but it is toxic so you probably should avoid breathing it)
As for asteroid impacts: the lack of air means if a big rock splashes
debris, it will reach the ground intact, whereas on Earth small debris
particles burn up. Of course, the catch is on Earth, the re-entering
debris from a large impact will turn the sky into an oven, which is
bad.
-- My reviews can be found at http://jamesdavisnicoll.com/My tor pieces at https://www.tor.com/author/james-davis-nicoll/My Dreamwidth at https://james-davis-nicoll.dreamwidth.org/My patreon is at https://www.patreon.com/jamesdnicoll