Landing people on Mars: 5 obstacles | Hacker News Reader

Landing people on Mars: 5 obstacles

usatoday.com

39 pointsedw51940 comments

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.)

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.

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.

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.

My guess is that the entire crew will be on some sort of antidepressant to reduce their libido and also the potential for "space madness".

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

That couldn't possibly go wrong.

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.

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.

There are literally millions of people who are capable of having transitory relationships that end with a manageable amount of drama.

Really, this is not an issue at all.

Have you read Stranger in a Strange Land?

What about Buddhist monks who live lives of celibacy? You're right, it is frivolous.

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.

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

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

Depressingly, the people who allocates funding see neither humans working on Mars nor a prolonged human exploration of space. What they see is usually limited to a guy planting a flag and making a speech.

Oh... and the money allocated to aerospace contractors from his/her state.

I like the incremental approach. If we can build the bulk of the spacecraft on the Moon, the solar system becomes our backyard.

We didn't have direct evidence that the Moon had water until recently (in late 2009 when the LCROSS mission impacted a shadowed crater in search of water: http://en.wikipedia.org/wiki/LCROSS#Presence_of_water)

But that's my point. It took us forty years from initial landing to find out if there is water on the planet exactly because we abandoned Moon landings.

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.

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.

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.

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.

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

Of course. Simple. Why didn't anyone else think of it. Let's just invent hard AI. Doh!

Er, how do we do that again?

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...

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.)

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-...

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.

"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?

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.

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.

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

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."

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.

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.

Sorry, but anybody who says anything never done before in space is 'trivially easy' has a serious credibility deficit.

Lots of things have never been done before. This appears to be a case where it's used as an excuse not to do it.

Terraform the moon first.

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

http://suite101.com/article/why-there-is-no-atmosphere-on-th...

i really hope this happens within my lifetime.

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