Post by James NicollThe 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.
Helium-3, for use in space exploration, not for use on Earth, may well
be an important reason for exploring the Moon. Deuterium on Mars? It
is to laugh, but I only noticed that in James' column, not when I read
Zubrin's book. Sadly, Mars isn't likely to have reserves of dilithium,
or unobtanium (not titanium, which you can find on the Moon, but the
stuff from Avatar)... or a library left behind by an ancient Martian
civilization including plans for FTL spaceships.
Mars gets hit by asteroids a lot more often than Earth. But if you're
in an underground habitat instead of breathing the local air, an
asteroid impact is a strictly _local_ catastrophe, not the global one
the dinosaurs experienced on Earth. So there is a _real_ reason for
settling Mars, and that's to ensure species survival. Underground
habitats on Proxima Centauri b, despite the solar flares, as a way to
survive both Sol and Alpha Centauri going off the Main Sequence, are
also a good idea in my opinion.
You could build similar underground habitats on Earth! Yes, but while
they protect against many hazards to be found in space, they're not
immune to the persistent efforts of an invading Russian or Chinese
army.
To me, though, the _biggest_ flaw in Zubrin's analysis is where he
dismisses concern about back contamination. Pathogens evolve over
millions of years to infect their hosts! We get hit by meteorites that
were knocked off of Mars!
He is right that we don't need to worry about Martian measles or
Martian malaria. But what I'm worried about is Martian mold and
Martian mildew.
Eukaryotic cells from Mars, if they existed, wouldn't survive the
journey to Earth on a meteor, so no, we haven't already been exposed
to all potential Martian pathogens. And the _kind_ of Martian pathogen
that could still prove to be a menace to life on Earth, despite not
having millions of years to adapt to infecting Earthly life forms, is
that which would simply ignore our utterly alien immune systems, and
view us as walking piles of sugars (and _possibly_ amino acids).
Sure, Mars is, with about 99.99% probability, utterly lifeless. But I
have a *very* low tolerance for any level of risk that we might just
turn the entire human population of Earth into green goo.
John Savard