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update: Water at the poles has some more recent news:

I just wrote a comment that includes the following sentence:

I think the J. P. Morgan of Mars will get rich shipping water from the ice near the poles to the people near the equator where it's sunny.

But I was being whimsical and not thinking it through.

While there is oxygen everywhere in the atmosphere (in the form of CO2) water for drinking and growing food (carbohydrates!) and for hydrogen for fuel (and perhaps other uses) on Mars might really need to come from water ice near the poles.

If regolith near the poles is say 20x more hydrated than near the equator where it's "warm and sunny" (also important for growing food), is there any even remotely, potentially economical way to move the water from the poles to the people?

Canali? Pipes? Trains? Hydrogen balloons? ATVs? Anything?

"Economical" I suppose would mean that it takes 20x times less excavation and processing resources per kg of water, but more resources to move it to where it's needed. Even more because it may be nonlinearly more difficult to extract any water from nearly dry 2% rock than from a nice juicy vein or layer of polar ice.

below: Here's an upload to Wikimedia; click for full size.

enter image description here

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  • $\begingroup$ Comments are not for extended discussion; this conversation has been moved to chat. $\endgroup$
    – called2voyage ♦
    Jun 14, 2018 at 12:44
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    $\begingroup$ Is this not a Worldbuilding SE question ? Is there any reason why you'd prefer to ask here rather than there ? $\endgroup$
    – Cornelis
    Aug 5, 2018 at 13:00
  • $\begingroup$ @Conelisinspace here I'm asking about building a pipeline or other common Earth-based structure that is well understood today based on information we already have about Mars today. There you are asking about planetary-scale modification of both Mars' surface and of it's atmosphere. $\endgroup$
    – uhoh
    Aug 5, 2018 at 13:11
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    $\begingroup$ You're asking about an imaginary Martian transporting system, and that's exactly what Worldbuilding SE is about, constructing imaginary worlds and settings. $\endgroup$
    – Cornelis
    Aug 5, 2018 at 20:52
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    $\begingroup$ Will answers to this question not tend to be almost entirely based on opinions, rather then facts ? Have you seen any economical calculations in the answers which justify the opinions that are put there ? $\endgroup$
    – Cornelis
    Aug 5, 2018 at 21:26

8 Answers 8

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You don't care about transporting H₂O. You want to transport hydrogen and oxygen atoms, and if that includes a few other atoms as baggage, that's no big deal. One easily available atom is carbon, as it can be extracted from CO₂.

So you need two pipelines. Hydrogen has the nasty property of escaping pipelines, so you need to bind it to carbon to produce CH₄. (Methane). It freezes only below 90K, which is not going to happen even on the poles. Oxygen can be transported as just O₂. It won't freeze either.

So, you need H₂O, CO₂ and a lot of energy to produce the CH₄. That's where you need nuclear energy; solar power isn't a good option near the poles. On the plus side, at your base you get a CH₄+O₂ stream that you can pour straight into a fuel cell. This recovers the H₂O and CO₂. You also get electricity and heat, which are also valuable, without having a nuclear reactor near your base.

Note that CH₄ and O₂ are also incredibly useful for a lot of other chemical processes. There will be a need to produce plastics, and CH4 is a reasonable source material for that.

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    $\begingroup$ Carbon has an atomic weight of 12 and Hydrogen of 1. So you would need 3 tons of carbon for each ton of hydrogen. What could serve as a source of that much carbon at the pole? Or alternatively, how do you get the carbon back to the pole after you split the methane? $\endgroup$
    – Philipp
    Jun 11, 2018 at 15:26
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    $\begingroup$ @Philipp: There's plenty of CO2 at the poles (as well as H2O). No need to get it back, turn it into carbon fiber or other useful stuff at your equatorial base. The biggest problem is actually the energy you need, the formation of CH4 and O2 is energy-negative. On the plus side, you can get some of the energy back at the base by reforming the H2O and CO2 in a fuel cell. So drop a nuclear reactor at the pole, at a very safe distance, and get heat+power+H2O in your base. $\endgroup$
    – MSalters
    Jun 11, 2018 at 15:45
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    $\begingroup$ Please beware that in your setting, the nuclear reactor at the pole may be "at a very safe distance" from people but not from your water supply. $\endgroup$
    – Pere
    Jun 11, 2018 at 19:10
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    $\begingroup$ It seems like it would be more economical to transport ice chunks in a conveyor-belt / pipeline combo, rather than using electrolysis to separate the molecules. You'd have to deal with the liquid, solid, and gaseous forms simultaneously, but that could likely be handled mechanically, within a single enclosure ("pipe"). $\endgroup$
    – jpaugh
    Jun 11, 2018 at 19:14
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    $\begingroup$ If you have nuclear energy, just colonize the poles. If your agriculture in space requires sunlight because you don't have a reactor, you can count me out. $\endgroup$
    – Mazura
    Jun 12, 2018 at 2:53
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Canals?

It's too cold on Mars for water to be liquid, so canals are not going to work.

Pipes?

...would need to be constantly heated, so they would require quite a lot of energy.

Hydrogen balloons?

The atmosphere on Mars is very thin. Hydrogen zeppelins would work in theory, but they would generate even less excess lifting force compared to their size than on Earth. But there are some interesting proposals for using balloons for mars exploration. Here is a paper about the topic.

ATVs?

You mean the Automated Transfer Vehicle from ESA? It might be better to use a cargo module which is actually designed to land.

But suborbital rocket flights for cargo transport might in fact not be as stupid as it sounds. The lower gravity and thinner atmosphere on Mars make them far more viable than on Earth. And you could repurpose a lot of the rocketry hardware which brought you to Mars in the first place.

...or do you mean in fact "All Terrain Vehicles"? Transporting cargo by rover will likely be the default solution for a while. An autonomous rover would take about a week to bring a load of ice from the pole to the equator. But it will be hard to design a rover with a range of 5000km, especially without fossil fuels.

Trains?

Building train tracks can be profitable if you want to transport very large amounts of material. But it's hard to calculate the break-even point in comparison to trackless trucks, especially because it's hard to calculate the cost of manufacturing rails on Mars.

But if you have a Mars colony of a sufficient development level that you have large-scale metallurgy capable of manufacturing thousands of km of steel rails and enough need for ice to justify the project, then it might be worth considering.

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    – called2voyage ♦
    Jun 14, 2018 at 12:45
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You don't need to. There's a lot of subsurface water ice at many mid-latitude sites, where that ice is easily accessible -- only a few meters down, sometimes even exposed, and mostly pure.

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pipes

In addition to other answers, while most of the time Martian temperatures average below zero, they reach positive side of the Celsius scale every day on most of the surface. That means that pipes with enough freeze-proof storage tanks interspersed throughout their run, and active pumping (draining pipes dry at night) should in theory allow a cheap and reliable, but slow transport of water step by step, or rather - tank by tank.

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  • $\begingroup$ I'm wondering which stays longer though, the cold or the warm; and the duration of each on a single Sol? Would the average ambient temperatures allow for pipes to thaw before becoming cool again? If not then it's just as wasteful as heated pipes. $\endgroup$
    – Magic Octopus Urn
    Jun 15, 2018 at 11:15
  • $\begingroup$ According to Wikipedia (extrapolating a bit) temperature is positive for at most 2-3% of mean martian day. Addressing the second question: minimizing pipe thermal capacity would allow them to operate the moment ambient temperature rises above melting point (melting point temperature is a function of pressure as well) $\endgroup$
    – loa_in_
    Jun 17, 2018 at 18:42
  • $\begingroup$ Seems like the dust storms would also need to factor into this. It would stink to build a pipe system assuming 2-3% ambient mean temp, then get a 2 year long dust-storm that freezes them permanently. $\endgroup$
    – Magic Octopus Urn
    Jun 21, 2018 at 13:56
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Moving the water requires energy and infrastructure. You'll want to liquefy the water and pipeline it around the planet to do that you'll need to heat it up which requires energy and infrastructure.

I'd propose putting enormous LFTR reactors on the poles and build a big pipeline around the entire diameter or mars. You dump the waste heat from the reactors into the ground to sublimate the CO2 out of the ground and thicken the atmosphere (still below the armstrong limit but every little bit helps). You use the tubes for 5 purposes:

  1. Data lines
  2. Electrical grid
  3. Supply pipeline
  4. ENORMOUS particle accelerator
  5. Gigantic electromagnet

The electromagnet will help to retain the newly thickened atmosphere and shield people from radiation. The data lines will keep the citizens happy with fast internet. The supply pipeline can be used to transport water, fuel, whatever around the planet, the particle accelerator will get scientists more interested in going to mars (read: more funding). Fission byproducts of a lftr reactor give you industrial exports (krypton-85 is a great ion engine fuel, iodine-131 and cesium-137 have medical applications, Plutonium-238 is useful in RTG's, etc..) Boom. You have a martian economy and some groundwork laid for terraforming.

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  • $\begingroup$ I don't know what an LFTR reactor is. Can you add a link? Also, this deviates from an answer to the question as asked. I've asked about moving water, you're answering about adding an atmosphere and building a particle accelerator. $\endgroup$
    – uhoh
    Jun 12, 2018 at 15:06
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    $\begingroup$ en.wikipedia.org/wiki/Liquid_fluoride_thorium_reactor Moving water requires energy and infrastructure, which the pipeline solves. $\endgroup$
    – Justin Braun
    Jun 12, 2018 at 17:07
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    $\begingroup$ +1 I see, thanks! In the future, use the @ function when addressing comments to someone in particular, that way they get a notification. I just found your comment by accident. Also, it's better to edit your post and add the information to it directly. Comments are considered temporary (if you look at the question, you'll notice two dozen of them have been moved just now). It's always best to include useful information directly into the original post where it's more likely to remain. $\endgroup$
    – uhoh
    Jun 14, 2018 at 12:49
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I see that many other answers or realistic propositions have been made. I would like to propose a rather out-there kind of idea. So the concept is that you could gather ice in some sort of bin with a deployable parachute large enough in size to slow the decent to an adequate speed in the Martian atmosphere. This bin could then be launched from near the poles via some sort of explosion. My guess is that the best bet would be to perform electrolysis to separate the water and recombine it to produce the desired explosion or crude fuel for a thruster. I am trying to gather information about the energy required to perform such a task here. Once that is accomplished, I could run a rough cost analysis. I will update this answer as soon as I can do so.

Note: This answer is not intended as an actual proposition, but is mainly created with the goal of having a place to present my analysis of this concept. Depending on the cost analysis, it may prove to be a legitimate solution to this transportation problem, however, it is likely far from the most efficient.

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  • $\begingroup$ This is more or less the suborbital hops idea that I suggested in a comment earlier. Probably better using a railgun or similar rather than an explosion, but it's energy either way. Slowing it down at the other end is a problem. The atmosphere is too thin to carry much energy away, and the kinetic energy per kg (about 5MJ) is enough to vapourise ice. I wondered about making an ice-covered lake in a crater and lobbing lumps of ice into that. The lake can absorb the energy and lose it slowly to the environment, while a nice warm (if slightly noisy) lake would be a nice thing to build next to. $\endgroup$
    – Steve Linton
    Jun 12, 2018 at 10:31
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It's a one-way ticket too. You want to be cultivating an ecosystem, and the water you pump into that ecosystem will be recycled. I've not really seen anyone else mention the fact that once you start bringing ice in from the poles (or wherever), there will begin to be an excess of it where it is being transported. For any long-term Mars solutions water processing plants and likely hydrolysis plants will be absolutely required. Once water has been moved to a settlement, and the levels of reserve water stabilize for the current population, there will be no need for additional water resources until more population arrives. The ISS is a great case study of this, it doesn't even have polar ice caps to mine, but you don't see the astronauts paying out the nose for bottled water either (hah, they pay in pee!).

It wouldn't be a J.P. Morgan style enterprise. I'd assume it would be more of a collective communal pool of resources until the surface of Mars was sufficiently populated. Even then, leaks could be minimal in terms of storage (liquid H2O). But you're right, anything dealing with low density gasses would be a constant replenishing war. I was just pointing out that to get to the point that a company had a monopoly on water we'd need a very large population density (colonization level, not outpost level).

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  • $\begingroup$ You've never heard of leaks? Fuel will need hydrogen, discarded waste (plastic, unrecoverable organics, all kinds of nasty stuff...) There will always be a need for some amount of make-up water, even for a constant population. $\endgroup$
    – uhoh
    Jun 15, 2018 at 12:57
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    $\begingroup$ @uhoh I suppose you're correct, my main point was that it wouldn't be a J.P. Morgan style enterprise. I'd assume it would be more of a collective communal pool of resources until the surface of Mars was sufficiently populated. Even then, leaks could be minimal in terms of storage (liquid H2O). But you're right, anything dealing with low density gasses would be a constant replenishing war. I was just pointing out that to get to the point that a company had a monopoly on water we'd need a very large population density. $\endgroup$
    – Magic Octopus Urn
    Jun 15, 2018 at 13:11
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    $\begingroup$ Water will be needed for rocket propellant. $\endgroup$
    – ikrase
    Jun 24, 2020 at 10:45
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It might be cheaper to mine water (ice) on Ceres. Delta-V from Ceres surface to Mars transfer is less than for the suborbital hop from Mars pole to equator (according to the spreadsheet I got from here) and you could use an ion drive or mass driver or something for the main boost, since you aren't in a hurry to get out of a deep gravity well (Ceres escape is about 500 m/s).

Of course there is the problem of stopping again. Your ice blocks will be coming down at rather more than Mars escape velocity. I still quite like the idea of flooding a crater (and then letting a few meters of ice form on the top). The incoming ice shipments keep the bulk of the lake liquid (if you schedule them carefully) but the ice crust will reform pretty quickly and stop you losing too much by evaporation. You can probably use some of the heat from the lake to warm your habitat as well. Of course it is very important to hit the lake and miss the habitat.

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    $\begingroup$ While this is a thoughtful comment, it's not an answer to the question as asked. $\endgroup$
    – uhoh
    Jun 12, 2018 at 15:04

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