Slashdot Mirror
How To Die On Mars
An anonymous reader writes: Many space-related projects are currently focusing on Mars. SpaceX wants to build a colony there, NASA is looking into base design, and Mars One is supposedly picking astronauts for a mission. Because of this, we've been reading a lot about how we could live on Mars. An article at Popular Science reminds us of all the easy ways to die there. "Barring any complications with the spacecraft's hardware or any unintended run-ins with space debris, there's still a big killer lurking out in space that can't be easily avoided: radiation. ... [And] with so little atmosphere surrounding Mars, gently landing a large amount of weight on the planet will be tough. Heavy objects will pick up too much speed during the descent, making for one deep impact. ... Mars One's plan is to grow crops indoors under artificial lighting. According to the project's website, 80 square meters of space will be dedicated to plant growth within the habitat; the vegetation will be sustained using suspected water in Mars' soil, as well as carbon dioxide produced by the initial four-member crew. However, analysis conducted by MIT researchers last year (PDF) shows that those numbers just don't add up."
perchlorates. Mars seems to be chalk full of them. There are some microbial lifeforms which are able to metabolize them, but we can't. In fact, their pretty bad for us. For large values of bad.
Do you know why the road less traveled by is littered with the bones of the unwary?
Nobody is seriously discussing terraforming Mars any time soon. The plan is to create artificial habitats.
But if we did - the atmopshere would be stripped away over the course of millions of years - fast by geologic terms, but not human. You just need to periodically replenish it, either with clusters of small asteroid impacts, or gasses produced from rock (for reference, oxygen is by far the most common element in the Earth's crust - with almost 10x as much as the second place element, silicon.)
In that scenario radiation would largely be a non-issue as, just on Earth, it would be stopped by the many miles of atmosphere. On Earth the magnetic field only deflects low- to medium-energy charged-particle radiation - mostly the solar wind. The rest gets (mostly) blocked by the atmosphere - which provides shielding equivalent to dozens of meters of rock.
And in the transitional phase, well, plenty of organisms can survive completely unprotected in space for extended periods. Assuming we engineer custom "Martian" life, I would imagine that radiation resistance and/or efficient DNA repair would be transplanted from such organisms.
--- Most topics have many sides worth arguing, allow me to take one opposite you.
I don't understand why people are finding any problems with that.
The problem is that sending people to Mars is very expensive and the billions of dollars wasted on sending people to die on an inhospitable planet could be better used for other things.
There is no parallel between a Mars outpost and explorers in the Age of Sail. On Mars people will be living in holes in the ground only able to go outside in cumbersome suits and will have to be supported by shipments from earth for a very long time possibly forever. All for no gain for Earth. Age of Sail colonies quickly became self sufficient and able to live off the land or they failed.
Mars 1 is a scam to make money for the promoters and nothing more.
There are known caves on mars, see here (has pretty pictures).
It's hard to get imagery of caves in the side of canyons from orbit, and our rovers haven't been down into the canyons much if at all, so we haven't seen them yet, but I would be suprised if there wasn't. Water/limestone is not the only way they can form - e.g there are known lava tubes on mars. Kim Stanley Robinson's Mars trilogy has a habitat in a lava tube. And we know that mars had a lot of water in its past - what do you think formed the canyons? :)
Also the caves where we build habitats don't have to be in canyons. From a logistical point of view it's probably better if they're not, i.e it's difficult to land a spacecraft in a canyon and annoying to drive from your non-canyon spaceport to your canyon habitat.
Heavy objects will pick up too much speed during the descent, making for one deep impact.
1. Speed gained during decent does not depend on weight of the craft.
:)
When considering aero-braking/parachuting/gliding the only thing that matters is lift/drag generating surface area vs mass
2. Speed gained during decent (from mars gravity) is nominal compared to orbital transfer speed/orbital speed that needs to be zeroed.
Mars orbital speed at 200km is around 2.4km/s, total amount of speed gained from direct decent from 200km to 0km on Mars is around 1.2km/s (with no atmosphere), in real life we would see orbital speed (2.4km's) decreasing on decent due to atmospheric drag (until it reaches terminal velocity, which depends on point 1. but should be less than 1km/s for any viable design).
Prior to achieving stable orbit around mars we have to (aero-)brake from at least 15km/s (orbital transfer). So theoretical 1.2km/s from Mars gravity (which actually doesn't happen) is a really small amount of additional velocity compared to the amount we have to brake anyway.
Playing a few hours of KSP should be mandatory prior to posting articles about space flight on the internet
Yes, sure, please describe how you plan to dig on a planet with sweet fuck all on it? I think you space prophets don't have the imagination it takes to envision the complete and utter lack of everything when you're dreaming about your Mars condos...
Wish I had mod points to mod this parent up. When people think about colonizing Mars, they picture some romantic red desert with cool domed habitats. Really, what you should picture is the absolute harshest environment you can imagine, and then multiple by 10. You are talking about a planet where the atmosphere is close to vacuum, bathed in radiation, with poisonous soil, with no support and no chance of rescue. If anything breaks, you better be able to fix it on the spot. It would be FAR easier to take the most inhospitable spot on earth and colonize it.
I'm all for space exploration, but let's keep our heads on here.
I love how these things are all "you simply have to do..." Like one goes out and collects the atmosphere with a butterfly net and splits it with a butcher's knife. Or like just goes and "gets a smelter and a foundry going".
Do these people have any clue how complex these sorts of industrial systems are? They have hundreds of thousands of components, all of which can break, and some of which are massive. The more you scale it down, the less efficient it becomes. And systems engineered on Earth don't just magically work on Mars too. You can't just dump heat into a river or the air, your gravity is significantly lower, and you've got electrostatic dust that clings to everything. And everyone output feedstock you want requires half a dozen or so input feedstocks, not counting all of the parts that can break - and they will break. And not all of these feedstocks can be gotten from the same location.
Let's just pick one little part of what you just wrote. "pass the CO over iron oxide dust" (we'll ignore everything leading up to getting and transporting that CO2). First off, if you literally do just that, you'll get nothing. The reaction needs to be done *hot*. And it can't be just "passing it over", it has to be thoroughly mixed. But then you get ready-to-use steel right? Wrong. Because you don't have "iron oxide dust". First off, you don't have any fine "dust" in mineable quanties, the blowing surface dust is spread over overthing, not accumulated in big pits ready for you to dig up.You at best have sand; at worst, solid rock. Most sands are not going to made of a majority iron oxide (if they have any sizeable quantities at all). Iron ore deposits are places where iron has been *concentrated* by geological processes, it doesn't make up the majority of basalts. And even cementations of iron-rich clay concentrates aren't 100% iron oxide. Whatever you mine (which means mining equipment, which means big, expensive, complex devices), you need to break it up, which means rock crushers, (which mean big, expensive, high wear devices), transport (haulers - more expensive devices), etc. At the mill it's going to go through a range of hoppers, conveyors, etc, all of which will wear and break. In addition to your ore and CO, you need a wide range of fluxing agents to separate out the stuff you don't want and to produce a usable product. The most critical of your fluxing agents is limestone, which on Earth mainly comes from deposits of marine microorganisms. Fat lot of luck finding that on Mars. So you need to mine less common calcium carbonate sources like travertine. More mining equipment. Hey, do you expect to find your travertine ten feet from your iron ore? Yeah, best of luck finding that, you've got to drive! Just hope you don't have to drive hundreds of kilometers, eh? Of course that's just one of a variety of fluxing agents you'll be wanting to add, there are many, for varying purposes. Anyway, once you've got your big molten mess (consuming ridiculous amounts of energy, orders of magnitude more than we've ever fielded offworld), you need to do something with it as you stream it out. Okay, then of course you have your slag skimmers. Hey, how long do you think that parts dripped in a stream of molten iron last? And you need to do something with your slag, so get your equipment to haul it away (after you've cooled it) ready as well. Speaking of cooling, normally we'd use water for that and just let it boil off for cooling, but on Mars it's a precious commodity, so go add more complexity for recapture and cooling! So now we've got a stream of mostly pure steel, but we're not even CLOSE to having usable parts.... (I'll stop here, as I don't want to spend all day on this).
I get it, you have a basic understanding of the chemical formulas for making a couple products. Well, here in the real world, a simple chemical formula is not enough. Real world processes are far more expensive and complex. They don't just pop together by waving a magic wan
POTUS Witch Hunt tracker: 75 charges filed against 19 witches, 4 witches cooperating and 5 witches have pled guilty.