Air. Shelter. Water. Food.

Oldfart1939 · 2017-04-23 09:18:58

Earlier in my life, I was heavily involved in high altitude mountaineering and extreme outdoor activities. I was also affiliated with the Rocky Mountain Rescue Group in Boulder, Colorado as a "Q" member, that is, a Qualified mission leader. We offered a lot of training for the locals back in those days, especially in regards to outdoor survival. We taught a rule of "30s." Thirty minutes without adequate shelter in extreme cold = fatal. Thirty hours without water = usually fatal. Thirty days without food = fatal. I'm going to add to this rule by saying 30 seconds without air = fatal.

Why am I bringing this up? Just as a model on which to build some focus within this discussion group, and for development of a set of priorities for the upcoming human missions. It's fun to speculate on what technology we can bring to the surface of the Red Planet, but this is all about "first things first."

This focuses on Air; without air, we may as well stay home and watch the ballgame. The inclusion of the Moxie unit in the 2020 mission is of highest importance, and all the other "science experiments" can wait awhile to be loaded into the "next" robotic explorer. These Mars rovers/explorers need to begin focusing strictly on human life support. I recently read that the Moxie unit my be bumped for some other "important" science experiment.

Shelter. We've had lots of discussion here about the Habitats, or as many are insistent on calling "Tuna Cans." If we face reality, we'll be getting OUT of these habitations and underground ASAP; the major, short term life endangering hazard comes from Solar Flares and the associated radiation bombardment of the planetary surface. I don't care if the structure associated with getting buried is flexible, inflatable, rigid, sulfacrete, whatever; just get it buried under several feet, preferably meters, of regolith. That will additionally help keep our frail human bodies from freezing to death during the Martian winters. Also, it reduces the intensity of GCR exposure to some degree.

Water. Water is the first key resource we need after Oxygen, since it allows a myriad of activities to take place, beyond drinking, food preparation, and human sanitation. I have no preconceived notions about which way to collect H2O, other than we need to do so IMMEDIATELY upon arrival. The American Indians had the saying "water is life." Equally true on Mars. This is where we really need to employ the KISS principle.

Food. I expect that the first missions will be entirely dependent of Earth supply; prepositioning of a 200% surplus above projected needs seems only prudent to me. Then, and only then, can we really start building greenhouses and doing agricultural experiments, which in reality is what will be taking place.

What I've attempted here is to refocus our thoughts, not on road systems, 3-D printers, massive solar arrays, but on SURVIVAL. Without survival, there is no future for Mars exploration.

Dook · 2017-04-23 09:47:18

You have to have two mini-Moxies built into the tuna can. A primary and a backup. You also need spare parts for each and the crew needs to be trained on how to fix them.

The Mars Hab also needs one large emergency pressurized oxygen bottle, four Mars suits with oxygen rebreathers, and a small portable oxygen bottle to discharge into the greenhouse when it's built to provide it's initial oxygen.

Getting under ground doesn't prevent you from freezing. It's cold soaked and permafrost. If the greenhouse is built over the under ground shelter, then you might have some heat reach the shelter.

As for water, the Mars Hab should have all of it's water completely contained. So should the greenhouse except for minor water vapor losses. A WAVAR unit and other zeolite panels should be able to replace these losses ten times over in summer.

We need to keep it simple? I agree. That means no methane production, no regolith gathering and processing for tiny amounts of some element that you can't eat or drink, no exotic Mars "aircraft hoppers", no robots. The crew spends time on building the initial base, maintaining equipment, and growing plants.

Food is going to be more of a problem than some of you think. The greenhouse temperature has to stay within a certain range of about 60 to 100 degrees F for vegetables to produce. We don't know if the greenhouse panels should be single, double, or triple pane. We don't know what the surface temperature drops to when there is a month long dust storm. If fruit trees are exposed to 50 degrees they go dormant.

I think a large buried complex underneath the greenhouse would provide the best solution for food because you can control the temperature and grow food in hydroponics.

louis · 2017-04-23 16:27:58

It's right we focus on ASWF as the core priorities.

On Mission One, I can't imagine we will do anything other than attempt to create a failsafe system. Two lots of everything, and not all in the same vessel makes sense to me. Land oxygen, food, water and a hab separately from the lander.

We need readliy available oxygen supplies that will last for several months. Then we need the Moxies or equivalent. I think we need the atmospheric extractor to guarantee water when we land and we need reliable, very thorough water recyling. We should also be ready to split water into hydrogen and oxygen, giving added assurance about oxygen production.

We need a range of foods: fresh, frozen, vacuum packed, chilled. Though we will probably supplement these supplies with Mars-grown salad vegetables on Mission One in an automated artificially lit farm hab module, we need to assume that fails and we have sufficient nutrition available as direct supplies. But I think a fresh food experiment will be good for nutritional status and morale.

Overproduction of water or oxygen, the likely result of the failsafe approach, means we can lay up supplies for following missions.

One point to make, all these systems can be trialled with lunar circumnaviations and landings in the run up to the Mars landing.

Oldfart1939 wrote:

Earlier in my life, I was heavily involved in high altitude mountaineering and extreme outdoor activities. I was also affiliated with the Rocky Mountain Rescue Group in Boulder, Colorado as a "Q" member, that is, a Qualified mission leader. We offered a lot of training for the locals back in those days, especially in regards to outdoor survival. We taught a rule of "30s." Thirty minutes without adequate shelter in extreme cold = fatal. Thirty hours without water = usually fatal. Thirty days without food = fatal. I'm going to add to this rule by saying 30 seconds without air = fatal.
Why am I bringing this up? Just as a model on which to build some focus within this discussion group, and for development of a set of priorities for the upcoming human missions. It's fun to speculate on what technology we can bring to the surface of the Red Planet, but this is all about "first things first."
This focuses on Air; without air, we may as well stay home and watch the ballgame. The inclusion of the Moxie unit in the 2020 mission is of highest importance, and all the other "science experiments" can wait awhile to be loaded into the "next" robotic explorer. These Mars rovers/explorers need to begin focusing strictly on human life support. I recently read that the Moxie unit my be bumped for some other "important" science experiment.
Shelter. We've had lots of discussion here about the Habitats, or as many are insistent on calling "Tuna Cans." If we face reality, we'll be getting OUT of these habitations and underground ASAP; the major, short term life endangering hazard comes from Solar Flares and the associated radiation bombardment of the planetary surface. I don't care if the structure associated with getting buried is flexible, inflatable, rigid, sulfacrete, whatever; just get it buried under several feet, preferably meters, of regolith. That will additionally help keep our frail human bodies from freezing to death during the Martian winters. Also, it reduces the intensity of GCR exposure to some degree.
Water. Water is the first key resource we need after Oxygen, since it allows a myriad of activities to take place, beyond drinking, food preparation, and human sanitation. I have no preconceived notions about which way to collect H2O, other than we need to do so IMMEDIATELY upon arrival. The American Indians had the saying "water is life." Equally true on Mars. This is where we really need to employ the KISS principle.
Food. I expect that the first missions will be entirely dependent of Earth supply; prepositioning of a 200% surplus above projected needs seems only prudent to me. Then, and only then, can we really start building greenhouses and doing agricultural experiments, which in reality is what will be taking place.
What I've attempted here is to refocus our thoughts, not on road systems, 3-D printers, massive solar arrays, but on SURVIVAL. Without survival, there is no future for Mars exploration.

louis · 2017-04-23 16:48:18

Oldfart1939 wrote:

What I've attempted here is to refocus our thoughts, not on road systems, 3-D printers, massive solar arrays, but on SURVIVAL. Without survival, there is no future for Mars exploration.

Whilst I agree the ASWF formula is the first thing we have to address, I think it would be a mistake to say Mission One is all about survival.

The Space X revolution is giving us more options.

The road system will be crucial from Day One. If you find that the water resources you expected to discover within your landing area are not as indicated, you will need to explore for water. Yes, you can slowly clamber over rocks in a suitably designed Rover but it makes a lot more sense to bulldoze the stones, rocks and boulders out of the way by simply fitting a blade to your all-purpose Rover and so create a cleared road trail. I think cleared road trails will be important to effective exploration.

3D printers are a key ingredient to a failsafe approach. It will allow a good deal of Robinson Crusoe improvisation should the need arise.
I think we need at least one for Mission One.

Massive solar arrays? Depends what you think is massive...600 kgs or thereabouts for your main power source in the case of a 100Kw ultra lightweight PV system? Not massive, really is it? I think if we can bring in the energy system (including batteries, cabling, converters, methane manufacturing and so on) under 5 tonnnes that's fine. Nuclear and PV are probably around the same sort of tonnage.

50 years ago we got two people to the Moon and back, with them staying on the lunar surface for a couple of days. I really don't think ensuring the survival of between 3 and 6 people in a journey to Mars lasting 3 years is beyond us, given all the may technical advances in the intervening 5 decades. But yes, survival is the first consideration.

SpaceNut · 2017-04-23 19:28:44

Unless the simple cache of each with out recycling can be landed close to each other for the first camp site then we are done.

So the preload must not be counting on an oxygen system (moxie or other) to function from touch down means we need the full mission duration available at the landing site. This same way of thinking will mean the same for food, water, fuel and plus power no matter what type will be used.

Now if we are landing all within a common style of lander rather than one off designs specialized for intended useage then we can as sugested putting to small moxies in each. That said the sabatier reactor for the ISS could also be doubled up in them as well. I would also put in the Russian electrolysis units for the feed hydrogen from the waste water. Which leaves the dry foods to be split in the left over mass alocation across the lander count to fore fill the redundancy question.

From another posted quote "15 percent of the payload of food, which is expected to weigh 9,660 kilograms (10.6 U.S. tons) for a crew of 6 heading out to Mars." so thats the out bound or return mass for the approximate 180 days either way but thats a far cry from the 500 day surface stay mass roughly 27,700 kg and a Red Dragon is just 2mT down mass at this point and thats with no water yet.....

louis · 2017-04-24 03:21:32

I did some rough calculations, on the tonnage of oxygen and presumably other gases required to create a safe air system. For a crew of 6 for oxygen alone that's 4.8 tonnes a year, so 14.4 tonne for three years. If we were "doubling up" that would be nearly 30 tonnes.

Personally I would say it's better to have direct supplies on the lander craft and pre-landed that keep you alive for say three months and have a fail-safe element (so always at least two "feed" routes to getting the oxygen) and at the same time having different technologies available to extract oxygen e.g. from air and from water. On Mars we could add extraction from regolith.

SpaceNut wrote:

Unless the simple cache of each with out recycling can be landed close to each other for the first camp site then we are done.
So the preload must not be counting on an oxygen system (moxie or other) to function from touch down means we need the full mission duration available at the landing site. This same way of thinking will mean the same for food, water, fuel and plus power no matter what type will be used.
Now if we are landing all within a common style of lander rather than one off designs specialized for intended useage then we can as sugested putting to small moxies in each. That said the sabatier reactor for the ISS could also be doubled up in them as well. I would also put in the Russian electrolysis units for the feed hydrogen from the waste water. Which leaves the dry foods to be split in the left over mass alocation across the lander count to fore fill the redundancy question.
From another posted quote "15 percent of the payload of food, which is expected to weigh 9,660 kilograms (10.6 U.S. tons) for a crew of 6 heading out to Mars." so thats the out bound or return mass for the approximate 180 days either way but thats a far cry from the 500 day surface stay mass roughly 27,700 kg and a Red Dragon is just 2mT down mass at this point and thats with no water yet.....

RobS · 2017-04-24 11:07:54

I'd land all the food for the surface stay with the crew, so we know they won't get separated from them (and that way if there's an abort the food is with them for the flight home). I'd land a spare set of supplies separately as an emergency. I'd use an inflatable habitat with about 500-600 square meters for 6 people (3 levels, 14 meters in diameter), inflate it in a small crater, and cover the top with sandbags or spray water on it. I'd land somewhere ground ice was a known quantity (unmanned rover preceding the final site selection). I'd land several tonnes of solar panels able to make close to 100 kw of power. I'd send at least 3 unmanned landers ahead with perhaps 14 tonnes of supplies each, one with the inflatable (which would probably mass close to 14 tonnes), one with some of the food and a 5 tonne pressurized rover, one with the rest of the food supplies and some of the solar panels and the greenhouse. I'd land the crew with their food supply, half the solar panels, two buggies (golf cart sized), their medical supplies, and basic science supplies. The rest of the science would go in lander 3.

I've probably forgotten something.

RobertDyck · 2017-04-24 12:06:40

I suggested life support equipment based on equipment currently on ISS. That has already been tested in space. I gave descriptions of equipment complete with mass and power estimates in Light weight nuclear reactor, updating Mars Direct.

Hamilton Sundstrand: if you're reading this please stop trying to hide your website from me. I'm recommended NASA or SpaceX or whoever simply buy your equipment. Consider this marketing for your equipment.

I said that because every time I posted specifications of their equipment, they moved their website. Took a lot of effort to find where they moved it to. In the end I couldn't find it again. Specifications I posted are a few years old, but directly from the manufacturer.

Basis: Regenerable sorbent to scrub CO2 from cabin air. Lithium hydroxide is lightest, but it's not regenerable. Silver oxide works, and an upgrade for the PLSS of EMU suits on ISS replaced the Lithium hydroxide canister with silver oxide sheet metal. The "extended duration orbiter palette" for Space Shuttle Orbiters used solid amine painted on Styrofoam peas. It's thermally regenerable. Not sure what Hamilton Sundstrand used for ISS, but it's thermally regenerated. That is heat plus laboratory vacuum sucks CO2 out of the sorbent, but rather than venting to space, it's compressed by a pump and stored in a pressure tank.

Next component is cabin dehumidifier. It recovers moisture from cabin air, including breath and sweat. That means it will include organic molecules that produce smells of bad breath and body odor. It'll smell like a locker room. That moisture is sent to the water processing assembly for filtration.

Oxygen Generation Assembly. You could call this the core of the system. It generates oxygen by electrolysis of water. I believe it uses a semipermeable membrane so it works in zero gravity.

Sabatier Reactor. This combines all the hydrogen from the OGS with half of CO2 recovered from cabin air to produce methane and water. The water is sent back to the water storage tank, which will end up back in the OGS. All the methane is vented to space. Currently the other half of CO2 is also vented in space.

Urine Processing Assembly. Filters urine to recover water. The water is sent to the Water Processing Assembly for further filtration. Remaining concentrated urine is packaged in plastic bags for disposal.

Water Processing Assembly. This can currently process wash water from a sink or shower, as well as water from the cabin dehumidifier and Urine Processing Assembly. The sink and shower were supposed to be installed in the habitation module, but since that module was cancelled, ISS does not have them. However, the WPA is capable of processing water from them. Hopefully they'll be installed on ISS some time in the future.

Space toilet: a hose collects urine, the toilet is only used for feces. The toilet uses an air stream to collect whever is deposited, then filters the air to return air to the cabin. Solid waste is vacuum packed in plastic bags for disposal. Toilet paper, tampons and sanitary napkins can be "flushed" down the toilet. Again "flush" means an air stream, not water. And everything sent down the toilet is vacuum packed for displosal. Those bags are put in empty cargo spaceships, which are de-orbited, burn up in the atmosphere and crash in the ocean.

Notice the current system makes no attempt to recover moisture from feces. Russia developed a vacuum desiccator toilet after Mir. They intended this as an upgrade for Mir2. The core module they built for Mir2 became the "Russian Service Module" on ISS. NASA complained the plumbing was too complicated so insisted Russia remove it before launch, use the same toilet as Mir. After the Columbia accident I bet they wished they had the improved toilet. Johnson Space Centre developed "Advanced Life Support Project" on the ground, which included an incinerating toilet to recover moisture. I point out that can be done with an electro-resistive oven, aka electric oven, not by burning anything. Whether the toilet is based on the Russian design or the JSC design, we should use a toilet that recovers moisture from feces.

I have suggested some sort of direct CO2 electrolysis device to augment this system. Not to replace it, just augment it. It could be based on MOXIE. The idea is to recover O2 from CO2 currently dumped in space. This should recycle that more tightly. Currently the system on ISS recycles water and O2 with 93% efficiency. Robert Zubrin's book "The Case for Mars" 1997 edition stated NASA wanted 95% efficiency before going to Mars. Hopefully the CO2 electrolysis and a new toilet will close recycling sufficiently to satisfy NASA.

Install all this in a Mars habitat. The ERV or equivalent will have something to collect CO2 from Mars atmosphere. Robert Zubrin's ERV would use Mars Atmosphere Carbon Dioxide Freezer (MACDOF). The ERV would also have a direct CO2 electrolysis device to produce oxygen sufficient to top-up the LOX tank. The CO2 electrolysis device on the ERV could be scavenged to replace the one in the hab. MACDOF + MOXIE (or whatever) could produce oxygen to breathe.

One experiment with the first science mission will be to collect Mars ice, melt and filter. That could be used to replenish water for the OGA. That would produce O2 to breathe from Mars ice.

So lots of backup modes.

louis · 2017-04-24 12:39:02

Thanks Robert - a useful summary of all the life support technologies.

The durability of these technologies could be tested in extended lunar analogue missions.

As long as there is built in back up, I think this will be a low risk mission.

RobertDyck wrote:

I suggested life support equipment based on equipment currently on ISS. That has already been tested in space. I gave descriptions of equipment complete with mass and power estimates in Light weight nuclear reactor, updating Mars Direct.
Hamilton Sundstrand: if you're reading this please stop trying to hide your website from me. I'm recommended NASA or SpaceX or whoever simply buy your equipment. Consider this marketing for your equipment.
I said that because every time I posted specifications of their equipment, they moved their website. Took a lot of effort to find where they moved it to. In the end I couldn't find it again. Specifications I posted are a few years old, but directly from the manufacturer.
Basis: Regenerable sorbent to scrub CO2 from cabin air. Lithium hydroxide is lightest, but it's not regenerable. Silver oxide works, and an upgrade for the PLSS of EMU suits on ISS replaced the Lithium hydroxide canister with silver oxide sheet metal. The "extended duration orbiter palette" for Space Shuttle Orbiters used solid amine painted on Styrofoam peas. It's thermally regenerable. Not sure what Hamilton Sundstrand used for ISS, but it's thermally regenerated. That is heat plus laboratory vacuum sucks CO2 out of the sorbent, but rather than venting to space, it's compressed by a pump and stored in a pressure tank.
Next component is cabin dehumidifier. It recovers moisture from cabin air, including breath and sweat. That means it will include organic molecules that produce smells of bad breath and body odor. It'll smell like a locker room. That moisture is sent to the water processing assembly for filtration.
Oxygen Generation Assembly. You could call this the core of the system. It generates oxygen by electrolysis of water. I believe it uses a semipermeable membrane so it works in zero gravity.
Sabatier Reactor. This combines all the hydrogen from the OGS with half of CO2 recovered from cabin air to produce methane and water. The water is sent back to the water storage tank, which will end up back in the OGS. All the methane is vented to space. Currently the other half of CO2 is also vented in space.
Urine Processing Assembly. Filters urine to recover water. The water is sent to the Water Processing Assembly for further filtration. Remaining concentrated urine is packaged in plastic bags for disposal.
Water Processing Assembly. This can currently process wash water from a sink or shower, as well as water from the cabin dehumidifier and Urine Processing Assembly. The sink and shower were supposed to be installed in the habitation module, but since that module was cancelled, ISS does not have them. However, the WPA is capable of processing water from them. Hopefully they'll be installed on ISS some time in the future.
Space toilet: a hose collects urine, the toilet is only used for feces. The toilet uses an air stream to collect whever is deposited, then filters the air to return air to the cabin. Solid waste is vacuum packed in plastic bags for disposal. Toilet paper, tampons and sanitary napkins can be "flushed" down the toilet. Again "flush" means an air stream, not water. And everything sent down the toilet is vacuum packed for displosal. Those bags are put in empty cargo spaceships, which are de-orbited, burn up in the atmosphere and crash in the ocean.
Notice the current system makes no attempt to recover moisture from feces. Russia developed a vacuum desiccator toilet after Mir. They intended this as an upgrade for Mir2. The core module they built for Mir2 became the "Russian Service Module" on ISS. NASA complained the plumbing was too complicated so insisted Russia remove it before launch, use the same toilet as Mir. After the Columbia accident I bet they wished they had the improved toilet. Johnson Space Centre developed "Advanced Life Support Project" on the ground, which included an incinerating toilet to recover moisture. I point out that can be done with an electro-resistive oven, aka electric oven, not by burning anything. Whether the toilet is based on the Russian design or the JSC design, we should use a toilet that recovers moisture from feces.
I have suggested some sort of direct CO2 electrolysis device to augment this system. Not to replace it, just augment it. It could be based on MOXIE. The idea is to recover O2 from CO2 currently dumped in space. This should recycle that more tightly. Currently the system on ISS recycles water and O2 with 93% efficiency. Robert Zubrin's book "The Case for Mars" 1997 edition stated NASA wanted 95% efficiency before going to Mars. Hopefully the CO2 electrolysis and a new toilet will close recycling sufficiently to satisfy NASA.
Install all this in a Mars habitat. The ERV or equivalent will have something to collect CO2 from Mars atmosphere. Robert Zubrin's ERV would use Mars Atmosphere Carbon Dioxide Freezer (MACDOF). The ERV would also have a direct CO2 electrolysis device to produce oxygen sufficient to top-up the LOX tank. The CO2 electrolysis device on the ERV could be scavenged to replace the one in the hab. MACDOF + MOXIE (or whatever) could produce oxygen to breathe.
One experiment with the first science mission will be to collect Mars ice, melt and filter. That could be used to replenish water for the OGA. That would produce O2 to breathe from Mars ice.
So lots of backup modes.

SpaceNut · 2017-04-24 17:58:36

Good numbers for mission preloading of any landing site that we should choose for a mars first mission. What we still need is the water total numbers for the crew of 6 for the duration of surface stay as that will be higher than the amounts used going to mars and returning later. I see that RobertDyck forum link to mars direct numbers does not list water so please post if you have this resource.

louis · 2017-04-25 05:31:02

Men should drink about 2 litres (3.5 pints) per day.

http://www.independent.co.uk/life-style … 90100.html

The U.S. system on the ISS collects condensate, runoff, and urine to create about 3.6 gallons of drinkable water per day.

http://mentalfloss.com/article/67854/ho … -water-iss

So in terms of drinking water the American ISS section produces enough for 8 men perhaps enough for 6 if you include water for other uses.

I think you would have to build in some failsafeness for the transit so you might want to take along several weeks' water supply. With pre-landing you should already know that you have water on the surface in the landing zone (either directly landed or extracted from the atmosphere).

We might also be able to rely on a device like this for emergency use:

https://www.ted.com/talks/michael_pritc … ter_filter

SpaceNut wrote:

Good numbers for mission preloading of any landing site that we should choose for a mars first mission. What we still need is the water total numbers for the crew of 6 for the duration of surface stay as that will be higher than the amounts used going to mars and returning later. I see that RobertDyck forum link to mars direct numbers does not list water so please post if you have this resource.

RobertDyck · 2017-04-25 05:57:52

louis, you forget that the Oxygen Generation Assembly works by electrolysis of water. When you include that, they consume more water than is produced. They have to keep shipping up water from Earth.

elderflower · 2017-04-25 06:48:52

Louis, the water filtration system shown in the video will be great, if there is a fresh water source. For saline water you need to filter it and then feed it to RO, crystallisation (aka freezing) or distillation plants to get rid of solutes.

Oldfart1939 · 2017-04-25 10:03:25

If the Mar regolith really does contain the stated amount of water, my earlier proposal in another thread of "mining" the soil for water makes even more sense. My initial proposal was dealing with the ice-regolith mixture by means of "strip mining" techniques, thereby making the availability of Skid-steer front loaders even more useful and important. Water accumulation could become the first "industry" on the planet. If we can get enough regolith inside one of the dome structures, a common piece of industrial chemical process equipment would seem to be the answer for massive water extraction, and that's a rotary vacuum tumble drier. Use a self-contained recirculating heating system along with collector vessels, and we can extract nearly pure water free from all the salts associated with regolith, including but not limited to, perchlorates. This is initially a batch operation, but could be run in a continuous ongoing manner. In my own company's plant operations, we utilized this type of equipment for drying our products on a massive scale. Trailers filled with mined regolith could be brought inside and all the subsequent evaporation of H2O prior to processing could be accumulated by simple condensation on the walls of a greenhouse.
The water consumption of a growing colony would seem to be one of the limiting factors determining the rapidity of expansion.

Oldfart1939 · 2017-04-25 10:23:07

This is essentially a laboratory version, and these were at one time made in a 50L capacity. I would replace much of the apparatus with either Stainless steel or some other light alloy for use in this purpose.

https://beta-static.fishersci.com/images/F81985~wl.jpg

GW Johnson · 2017-04-25 10:53:58

Well, if you drill down and just happen to find a massive buried glacier, and you have a source of waste heat (such as a nuke reactor electricity source), you could steam-extract buried ice as water. Vacuum-flash distillation (very easy on Mars) gets you clean fresh water. That might not be near the work of processing tons of regolith for liters of water. But, do not extract right beneath your facilities, quarters, or vehicles. There is a risk of collapse.

GW

Oldfart1939 · 2017-04-25 11:05:15

GW-

I'm simply making an attempt to put my industrial chemical experience to some good use on this website. In my career, I've used an awful lot of the technology which seems useful but of which wannabee Mars explorers are ignorant. The easiest way of purifying water is through vacuum distillation. Every Navy ship has distillers for seawater desalinization. Even the barf bucket that hauled my carcass to Germany in 1963 never had a shortage of fresh water with 1450 soldiers onboard.
If the water produced by the vacuum flash evaporation process still has some issues, i.e., bad odor or taste problems, then a polishing filter of activated carbon would help. Not necessary for water to be electrolyzed or for showers, but drinking and food preparation--yes.

RobertDyck · 2017-04-25 11:11:06

Ground penetrating radar from orbiters will tell you where large glaciers are. Not small ones, the orbiters can only detect large ones. But you want the large ones. MARSIS on Mars Express can image to a maximum depth of 20km, although a lot of variation or detail in subsurface geology will reduce depth it can image. Still, it sees kilometres. SHARAD on Mars Reconnaissance Orbiter has higher resolution radar, but the trade-off is it can only image to a shallower depth. And there are some glaciers right at the surface, so digital cameras can image them. Here's one imaged by HiRISE on Mars Reconnaissance Orbiter. The problem is surface glaciers tend to be high latitude.

elderflower · 2017-04-25 15:53:03

For good taste in water from evaporators or RO plants, you also need to remineralise it a bit. A few ions need to be added: a bit of lime, a smidge of magnesium and sodium, some sulphate, chloride and carbonate. Also add some dissolved air. After that it will taste lovely and you will be able to put it in plastic bottles and sell it.

Oldfart1939 · 2017-04-25 17:17:46

Add some sugar and flavors: Mars-ade.

SpaceNut · 2017-04-25 18:54:51

I think the only question remaining are none of these items that follows as after much work on the water collection in the "DeGrasse Tyson's Mars challenge to Elon Musk" topic, which gives also a clear path to Oxygen is not additional natural shelter as I think with all the landers bringing stuff to mars we can reclaim them for additional living space and once we do decide on the methods to grow the food all that remains is the power sources....

Oldfart1939 · 2017-04-27 09:22:10

The most important feature of the entire program is having adequate energy available in order to have the capability of running the Moxie systems and water extraction systems--whatever they may be. Everything we're talking about on these various threads presupposes having ample power to support these applications. Louis and I diverge in our viewpoints--I favor nuclear, while he favors a massive solar array. The advantages and drawbacks of both systems are there to discuss--rationally. I'm going with the nuclear option since it's the original Zubrin proposal. I believe in the long view, we'll be using both. Humans are really energy hogs, and will feed at the trough of available power.

When we consider the ISRU aspect of the Mars Direct and Mars Semi-Direct architectures, manufacture of both Oxygen and Methane could consume almost all the power from a 100 KWe nuclear reactor; whilst the solar arrays could provide for the living spaces energy requirements: Air, warmth, and water production, cooking energy, computers, communications, etc.

louis · 2017-04-27 11:50:40

Are we such energy hogs?

http://data.worldbank.org/indicator/EG.USE.ELEC.KH.PC

The world electricity average usage is about 9Kwhs per day or 0.375 Kws constant (93 sq. metres of PV on Mars).

Even if we assume that the Mars colony will be per capita energy hogs compared with their Earth cousins, even their American cousins, they are unlikely in the long term to need hugely more than the 100 Kws average constant for 6 colonists posited in the MIT paper - an average of 16 kws per person going forward.

There will be a peak probably as we develop, initially, artificially lit farming. We might need say 2000 sq metres of intensive hydroponic farming (many crops per annum) to feed each individual. That could be 328 KWs constant per person. That is a lot of course. I could imagine an early Mars colony of say 100 who might need perhaps 400 kw x100 = 40 megawatts. But on the basis of the MIT paper that's only 1000 hectares (just over 3 kms by 3 kms) devoted to PV Panelling and that can of course be brought in in phases rather than having to be rolled out all at once.

Beyond the very early colony, though, I think we would be moving rapidly to naturally lit farming (probably enhanced with solar reflectors illuminating specially designed farm domes) and that figure of 400 Kw per person would fall dramatically. Maybe a figure like 50 Kw per person in that new phase would be more realistic. It would still be high because the colony would be building its infrastructure: constructing homes, vehicles, factories, roads and farm domes.

Another feature of the developing colony will be that it can meet its own energy needs without importing energy facilities as long as it avoids nuclear power.

Initially we will see solar concentrators generating energy for steam generators that provide both heat and electricity.

But the ability to produce PV panels is likely to come a lot earlier than we used to think, thanks to 3D printing.

This is partly why I am opposed to nuclear power. You can see how nuclear power came to be seen as very useful in a world of 7 billion people. Likewise, you can see why people are drawn to it for Mission One because it gives the illusion, if not the reality of, failsafe power.

But it is inflexible and will hold back the colony if it becomes the key power source. I personally don't have a problem with RTGs as back up for the early missions but larger nuclear reactors would be a mistake in my view.

Oldfart1939 wrote:

The most important feature of the entire program is having adequate energy available in order to have the capability of running the Moxie systems and water extraction systems--whatever they may be. Everything we're talking about on these various threads presupposes having ample power to support these applications. Louis and I diverge in our viewpoints--I favor nuclear, while he favors a massive solar array. The advantages and drawbacks of both systems are there to discuss--rationally. I'm going with the nuclear option since it's the original Zubrin proposal. I believe in the long view, we'll be using both. Humans are really energy hogs, and will feed at the trough of available power.
When we consider the ISRU aspect of the Mars Direct and Mars Semi-Direct architectures, manufacture of both Oxygen and Methane could consume almost all the power from a 100 KWe nuclear reactor; whilst the solar arrays could provide for the living spaces energy requirements: Air, warmth, and water production, cooking energy, computers, communications, etc.

Oldfart1939 · 2017-04-27 12:27:47

Louis-

I'm actually more concerned with having fail-safe energy production as an insurance policy for the return to Earth portion of the mission(s). There have been many times when the planet has been subjected to dust storms lasting nearly an Earth year, and it would be fatal to rely on just solar power to keep everything running--especially any artificially lighted greenhouses. I really don't see this as an either-or situation, but as I've stated earlier, will require both technologies. As a somewhat more aesthetic issue: I consider both solar farms and wind farms as massive eyesores. I'd really like to preserve the Martian landscape for viewing. Structures with solar panel roofs? No problem from me. Nearby the base for small solar setups? Again, no problem. Covering the landscape with acres and acres of solar panels? No thanks.

elderflower · 2017-04-27 12:39:00

Large reactors will be a stopgap pending availability of fusion reactors (don't hold your breath, though). Mars is well suited to fusion due the abundance of deuterium, it just needs someone to figure out how to make it go!
Meantime we should ensure diversity of energy supply so that failure of one source doesn't destroy the mission.
Suppose, for instance that a resupply lander gets a bit sideways and ends up blowing a big hole in your panel array or takes out one of your substations or a reactor. you had better have a good spread of devices and redundancy among them. Think its not likely? The military contrives all too often to have friendly fire incidents....

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