

Landing people on Mars: 5 obstacles - edw519
http://www.usatoday.com/tech/science/space/story/2012-09-02/Mars-obstacles-for-humans/57516356/1

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danielweber
_and the higher the odds of a catastrophic collision with a meteoroid_

This is silly. The dangers to a mission from a meteroid are essentially the
same for a six-month mission as a six-day mission: nil when compared the to
the risk of blowing up on the launchpad.

 _Chang-Diaz is developing an advanced plasma propulsion system that would cut
the round-trip time on Mars missions to five months_

Ugh. We can already get to Mars in six months using chemical rocket engines
right off the shelf. If Chang-Diaz thinks people can accept nuclear reactors
in space, then we should just pull out the Nuclear Thermal Rockets we've
already built and use them instead.

 _EDIT_ : I now see he is saying _roundtrip_ being 5 months. This doesn't
violate the laws of physics, but it does require nuclear reactors in space
with massive energy-to-mass ratios, well beyond anything we've built for
anything on the ground or in space before.

 _Spacecraft propelling astronauts to Mars — and habitats on its surface —
must be equipped with shielding sufficient to block space radiation._

Or you can just take your dose. The cosmic ray dose from a round-trip Mars
mission would increase your chance of cancer over your lifetime from about 20%
to about 21%. This isn't something you would want to expose the general public
(or even the janitor in a nuclear power plant) to, but it's petty when talking
about the risks to crew safety from the Mars mission. Launching a extra spare
habitat or earth-return-vehicle to Mars will be a better bang-for-the-buck in
terms of decreasing mission risk, with the bonus that we need to do it anyway.

(This is different from blocking solar flares. Those can and probably will
kill the crew dead if they aren't shielded from those. But that shielding is
more straightforward as the article says.)

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FrojoS
Climbing Mount Everest: 5 obstacles (usyesterday.off, 1952)

1) Trip time

A round-trip human expedition to the top of Everest, using current technology,
could take two to three weeks. The slower you go, the more supplies you are
forced to take and the higher the odds of a catastrophic collision with a
rock. Mountaineers would lose more energy and regenerate slower as a result of
the longer stay in high altitude. And they would be exposed to larger doses of
cosmic rays and solar energetic particles, increasing the probability of
cancer.

2) The Big C Problem: Cancer.

Mountaineers traveling to the top of the world, or working on its surface,
will be exposed to potentially high doses of sun [...]

3) Sex in Tibet [...]

4) The Yeti [...]

\-------- my 2 cents:

You can sit there and keep talking like this or f __*ing go do it. A 5 year
old today who wants to win the Olympics in 100m works every day for over 10
years for his or her goal. No guarantees of any kind. If we approached Mars
the same way, our fathers would have walked on it already.

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Almaviva
The sex issue is just frivolous. E.g. I haven't had anything but rejection
from a woman in three years, I'm perfectly healthy and functional, and I'm not
being carefully chosen for one of the most groundbreaking missions for the
human race.

~~~
elorant
Yes but I guess the women who rejected you don't live in the same house as you
do. Imagine living in close quarters with a bunch of people and some of them
are having sex while you don't. You'd have to seclude yourself from them to
suppress your feelings and then the whole project would go south.

~~~
drcube
So you get a set of known stable monogamous couples to go. Or one big
polyamourous family.

~~~
7952
That couldn't possibly go wrong.

~~~
drcube
Certainly things could go wrong. But I would argue having a set of people in
established, stable relationships is better than either A) having unattached
astronauts who will inevitably try to start relationships with each other,
leading to a dangerous space soap opera, or B) having a unisex, hetero crew
and expecting them to be celibate for years with no problem.

~~~
omarchowdhury
Seriously, if people can make celibate vows on the surface and keep them, they
can do it in space, especially if they are selfless enough to realize what
they are doing is to benefit their species; personal gratification being set
aside.

Monks can train themselves to be celibate, where sexual thoughts and feelings
become superfluous and uninteresting, so why not astronauts? It's all about
discipline.

And there's always the option of having plenty of sex before going up and
self-relief when you need it. If pleasure is more important to someone than
advancing humanity, then by all means stay on the ground.

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elorant
I never understood why we abandoned the Moon. It’s only three days away
compared to the eight months it takes to get to Mars and it also has water. We
should first establish a base on Moon and then venture on to other planets.

~~~
lumberjack
There are two schools of thought on how we should approach manned Mars
exploration:

1\. The incremental approach, the NASA favorite, the outrageous proposal that
got dismissed due to budget costs. It involves build a base in orbit or on the
moon and using it as a relay between Mars and Earth.

2\. Mars Direct. Reducing a lot of the complexity of the incremental approach.
Using available technology. Launching directly from Earth. Using a multitude
of vessels to setup an outpost on Mars before human arrival. Generating oxygen
and hydrogen before human arrival from the abundant methane on Mars. Cutting
the previous budget proposal by more than half. An estimate of ten years of
work required.[1]

Both have their advantages and disadvantages. Mars Direct seems like a more
realistic and pragmatic proposal but the incremental approach is more
visionary. Something that most of us laymen don't often consider is the
aftermath. We see the objective a human working on the red planet whereas I
believe most at NASA are more interested in prolonged human exploration of
Mars.

[1] <https://en.wikipedia.org/wiki/Mars_Direct>

~~~
sehugg
NASA's previous administrator championed a lunar base as a prerequisite for a
manned Mars mission -- if only to prove that we could send a crew up for an
extended period of time without resupply. I never understood this reasoning.
We have plenty of ways to engineer and simulate these conditions on Earth
(like the MARS-500, recently completed -- tl;dr, it's not fun, but they didn't
dismember and eat one another).

The only reason to stop en route to your destination is to refuel. This allows
a larger spacecraft to be launched with a smaller rocket (of course you need
more rockets to launch the fuel).

<http://www.nss.org/articles/depots.html>

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alpeb
About the quarter pounders transportation problem, space elevators sounds like
a great solution. Still, doesn't sound like a big gain to get humans to Mars
besides as a trophy. Better to send machines with tech greater than 90's 2MP
cameras. We're all gonna be replaced by machines anyway after the singularity
in a few decades.

~~~
simonh
1960s Herbert Simmons predicts "Machines will be capable, within 20 years, of
doing any work a man can do."

1993 - Vernor Vinge predicts super-intelligent AIs 'within 30 years'.

2011 ray Kurzweil predicts the singularity (enabled by super-intelligent AIs)
will occur by 2045, 34 years after the prediction was made.

So the distance into the future before we achieve strong AI and hence the
singularity is, according to it's most optimistic proponents, receding by more
than 1 year per year.

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bluesnowmonkey
Alternative Solution (to all of the above): Build better robots. As in, hard
AI. Has the additional advantage of allowing exploration of not only Mars, but
every other body in the solar system, and at not much greater a cost.
Potentially even other stars. Also improves nearly every other aspect of human
existence.

~~~
FrojoS
Landing people on Mars is most likely feasible with out major breakthroughs in
science and technology. In contrast strong AI might be around the corner - or
a million years away. Its much less predictable.

~~~
lotu
As a CS student who has done some AI research I can tell you strong AI is not
around the corner.

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mcdowall
This subject keeps coming up and just won't go away, the problem is that most
of the points raised essentially come down to funding, if we really wanted to
go there (or the moon) and setup a base, then we would have by now.

Other than SpaceX does anyone know of any private organisations trying to do
this? I for one would quite happily get involved, as I am sure would others,
happy to setup a Kickstarter page...

~~~
genwin
I do hope it's a private venture. My kids will have to work too many years
longer as it is, to pay for all the other things. (I know that space travel is
so cool that we're supposed to ignore the consequences of borrowing money for
it.)

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edstock
I read a while back that one of the biggest issues with a human mission to
Mars is the landing, I can't remember the article but a brief search turns up
this one that covers the relevant points:
[http://www.universetoday.com/7024/the-mars-landing-
approach-...](http://www.universetoday.com/7024/the-mars-landing-approach-
getting-large-payloads-to-the-surface-of-the-red-planet/)

~~~
kalms
I would have agreed with you a few months back, but after seing the airdrop of
Curiosity unto the surface of Mars, I have assumed a stance of quiet
fascination. Looks solvable to me.

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S4M
_"The long voyages in weightlessness are bound to substantially debilitate the
crew," he added. "At Mars arrival, they must have a way to rehabilitate
themselves before going to work, a tall order for the first mission in a very
hostile environment."_

Is that really a problem as gravity is much lower on Mars than on Earth?

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mmanfrin
tl;dr: It'll take a long time, people will have much more exposure to
radiation (and cancer), people need sex, muscle/bone degradation from being
that long in space, and cost of getting things there.

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drcube
Why isn't artificial gravity considered a solution to extended periods of
microgravity? Just spin the ship at the right speed and have the living
quarters on the outer rim.

~~~
apendleton
It is. From the article: "A rotating spacecraft would create artificial
gravity that would keep astronauts in tip-top shape."

~~~
nkoren
Strangely, the article fails to follow this up with the next logical sentence,
which is:

"Also, a rotating spacecraft is trivially easy to implement, meaning that the
entire zero-gravity argument is nothing more than a ridiculous canard by those
who'd rather suck down a few more tens of billions of pointless microgravity
biomedical research before allowing us to leave Low Earth Orbit and do
anything interesting."

~~~
lotu
Nothing involving rocketry is trivially easy implement. To my knowledge
building a centrifuge to produce artificial gravity has never been attempted,
it would take years of work and tens or hundreds of million dollars to design,
prototype, test, and man rate any such a system.

~~~
nkoren
Sure, you'd have to engineer it correctly and this would not be cheap. But in
the context of all the other things you'd have to spend money on to do a
successful Mars mission, it IS trivial. Artificial gravity can be as simple as
putting your habitat at the end of a tether, with a counterweight (say your
Mars injection stage) at the other end. That's about 1/100th the complexity of
the Sky Crane manoeuvre that NASA just pulled off, and certainly nowhere near
being one the "top 5" engineering challenges.

Unfortunately, the approach for the last several decades has been to say
"gosh, microgravity is scary, maybe we can RE-ENGINEER THE HUMAN BODY to can
cope with it". That's a canard. Spam in a can at the end of a string is
trivial in comparison.

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Kilimanjaro
Terraform the moon first.

~~~
jschuur
The Moon's gravitational pull wouldn't be enough to retain an athmosphere:

[http://suite101.com/article/why-there-is-no-atmosphere-on-
th...](http://suite101.com/article/why-there-is-no-atmosphere-on-the-
moon-a102634)

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accarrino
i really hope this happens within my lifetime.

