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#1 2021-04-06 03:08:00

Noah
Member
From: Zurich (Switzerland)
Registered: 2020-07-28
Posts: 38

Settlement design

goal

(For good quality open: https://i.imgur.com/3Vuueu9.png )
SD_plan

goal

The goal can and should change over time.

Discussion
I will periodically post a topic  I am working on or will be working on and if you have any advice or useful information, feel free to post a comment.

Last edited by Noah (2021-04-26 21:53:25)

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#2 2021-04-06 06:02:57

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,676

Re: Settlement design

For Noah re Post #1 of Topic Settlement design

Bravo for a bold start to what I am confident will become a long lived and much valued topic in NewMars!

This post can serve as a Table of Contents and Index to posts that are appended as members are inspired.

For all who are not currently members but who would like to assist with Noah's project ... please read Post #2 of the Recruiting Topic, and apply at NewMarsMember * gmail.com.

Table of Contents:
Post #1: opening image General Plan & Questions

Index:
Questions for Topic Post #1
Plan, General Post #1

Links to related posts and topics already present in the NewMars archive:

(th)

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#3 2021-04-06 06:11:43

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,676

Re: Settlement design

For Noah re growth of this new Topic ...

All those who have been or are now engaged in Settlement Design are candidates to be invited to join the forum and participate in development of the topic.

It is your opportunity to contact them and invite them to participate.

I can and will (to the best of my ability) support the mechanical/procedural activities needed to bring them into the membership.  Just advise them to read Post #2 of the Recruiting topic, and apply at NewMarsMember * gmail.com

There are a number of videos of City design in the YouTube collection for the 2020 Mars Society Convention.  Some of those have multiple participants. it seems to me quite practical and reasonable for ** all ** of those individuals and groups to join your undertaking here.

There are multiple visions in the videos and in other venues, including a large scale well-funded initiative that appeared on the global scene recently.

Not ONE of the ideas in early development is superior to another.  All can thrive here, and hopefully go on to become the nucleus of an actual venture in coming decades.  Your leadership is key to the potential success of this topic.  We (administrators and moderators) can help with the plumbing that insures smooth operation.  Our existing members can help (and surely ** will ** help) with encouragement and contributions of various kinds.

****
http://newmars.com/forums/viewtopic.php … 62#p178262

email sent for exploring the chances for a new topic folder area for colonization and settlement.
Such things as the My hacienda and Elon musk dream mars would fall under the topics, possibly a toe hold or foot hold would go in there.
Topics of voids and Louis come to mind as well for what are other example author's.

Please note that the archive of this forum extends back 20+ Earth years ... it contains many posts and some entire topics that fit into your framework.

it will be the work of many months to collect pointers to them all and blend them into the framework here.

(th)

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#4 2021-04-06 06:23:24

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,676

Re: Settlement design

For the historical record, Sagan City (2018) is defined for a future on Mars. 

My Hacienda is a framework for gathering of 7,800 individuals and organizations interested in creating an interlocking network of economic and social activities that would be needed to sustain a First Tier civilization on Mars.   The theory of design of Sagan City is the proposition that well planned Capitalism can meet the needs of a population away from Earth, and the needed specializations are in collection in the PlotMaster / Registry / Recorder  in the My Hacienda topic.

http://newmars.com/forums/viewtopic.php … 75#p154875

Anyone who would like to take "ownership" of a (Virtual) plot is welcome to do so.  Contact NewMarsMember * gmail.com.

(th)

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#5 2021-04-06 09:02:37

Oldfart1939
Member
Registered: 2016-11-26
Posts: 2,238

Re: Settlement design

Then Temperature regulation must be added to the LSS topic. Staying warm and unfrozen is of great importance!

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#6 2021-04-06 10:16:21

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,676

Re: Settlement design

For Noah re topic

Please implement the suggestion from Oldfart1939 in the image you've posted in Post #1 of the topic.

You cannot possibly read all of the posts by Oldfart1939, but please run Search to find references to chemistry

The list of citations is only 3 pages (< 150 posts) but the first one from 2020-09-22 contains biographical information.

(th)

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#7 2021-04-06 11:10:52

kbd512
Administrator
Registered: 2015-01-02
Posts: 4,737

Re: Settlement design

Energy:

When modern civilization was built on Earth, humanity had cheap and easy access to vast quantities of coal / oil / gas that could be burned in an oxidizing atmosphere, along with a strong but light natural composite material, better known as wood.  Since we don't have any of that on Mars, we need nuclear power.  No part of modern civilization was ultimately built using solar panels and batteries.  NASA can use them successfully because they can afford to spend a million dollars per kilowatt of energy output and their spacecraft are either robotic (and thus have a hibernation mode that doesn't equate to death, unlike humans) or operate in full Sun in a hard vacuum for a significant period of time (such as orbiting the Earth).  Heat engines of various forms were and are the bedrock of technologically advanced human civilizations, and no technologically advanced human civilization operates without them.  Novel yet inefficient and intermittent power sources such as solar panels and wind turbines were and are almost exclusively built using fossil fuels, and lots of them.  They certainly have their uses in an energy-rich environment, but Mars is very energy-poor, in terms of both sunlight and wind.

Since all robots and machine tools require copious quantities of energy, spare parts, and highly skilled technicians to operate and repair them, an absolute minimum of specialized tooling should be required to first produce habitable living spaces.  After the pressurized living spaces have been constructed, then we can experiment with every other inefficient and intermittent power source we can concoct, but not a moment before then.

Initially, every bit of the energy provided and tooling to produce or repair machinery must be imported from Earth, at fantastic energy cost, so the ultimate viability of any particular technology is very closely tied to its ultimate durability.  At present, nuclear reactors are some of the most durable machines that humanity has ever created.  There are no solar panels or wind turbines that have operated continuously for 70+ years, for example, although solar thermal power plants can also achieve the same level of durability as nuclear thermal power plants.  The longest continuous operation of any spacecraft in space was achieved using nuclear decay heat, not solar panels.

Anything that doesn't absolutely require computer-control should be studiously avoided.  The life support and communications systems need to be computer-controlled, but that's about it.  You can repair a worn-out air tool such as a drill, using hand tools.  The same can't be said of a battery-powered drill.  If the battery or electric motor or microchip that controls the battery charge / discharge dies, then the only viable option without access to the factory that produced it, is to replace it.  Home workshop amateurs have been fixing air tools for decades without the benefit of any advanced degrees in electrical engineering or factories.

Unlike virtually all sci-fi movies, all airlocks on actual spacecraft are hand-operated and inward-opening, for good reason.  If it doesn't have a motor or battery or electronics that can fail.  Said "machine" needs to achieve a good seal to hold pressure, but that's it.  If the pressure isn't equalized between the visiting spacecraft and space station module, then a human isn't strong enough to break the seal and kill everyone, whereas a powerful electric motor could.  Building needless failure modes, especially lethal failure modes, into machines is counter-productive and expensive.

The overriding point is this:

Don't create a Rube Goldberg of a device, merely to satisfy an engineer's desire to prove how intricate and complex they can make a simple task.  If a hand-operated bit driver can get the job done acceptably well, then you don't need a battery-powered computer-controlled drill and charger.  Simple machines may never attain the absolute pinnacle of achievable efficiency through electrification and computerization, but they also tend to be very reliable and durable.

Building with less energy and fewer resources:

The most practical construction materials are Sulfur-based concrete bricks made from local Sulfur and aggregates, preferably finely ground, surrounding Aramid fiber-reinforced polymer pressure vessel / liners.  Once locally-produced Basalt fiber-reinforced polymer for locally made composites becomes available, that will likely be the cheapest / most readily available material for pressure vessel construction.

Cleaning:

There's no such thing as a building in a desert environment that requires "almost no cleaning", so don't waste time on impossibilities and instead figure out how to efficiently and effectively clean critical areas in the pressurized spaces.  This is a frontier environment, not a clean room.  The Navy cleans their ships at least once per day, even when they're hundreds of miles from the nearest land.  Despite that fact, the ships are still filthy, which is why they're cleaned once per day.  You can and should do your best to "dust off" prior to coming into the habitat module, but that's as far as that goes.  Outside of a clean room environment, dust / dirt / grime is simply a part of life, and people need to accept that.

Repairing:

The fiber-reinforced plastic pressure vessel liners can be repaired in a matter of seconds to minutes, but rapid repair (mere minutes to a couple of hours) is not possible using traditional construction materials (bricks / beams- material doesn't matter / windows; but rapid replacement could be feasible, given a sufficient stock of spares), so focus fabrication efforts on producing smooth / dimensionally accurate bricks to surround the pressure vessel, along with enough spare windows and bricks to replace any that get damaged.

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#8 2021-04-06 12:04:41

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 6,788
Website

Re: Settlement design

Did you want answers? First life support. I see multiple life support systems, configured so you can mix-and-match components. That gives options should equipment fail. On a planet with no breathable atmosphere, a robust life support system with multiple backups is necessary.

Chemical/Mechanical based on ISS: electrolysis of water
Regenerable CO2 sorbent: That means a fan to blow cabin/habitat air through a sorbent, which will absorb/adsorb CO2. Periodically the sorbent is "baked out". The CO2 released will be compressed, stored in a pressure cylinder. Mercury/Gemini/Apollo used lithium hydroxide (LiOH) because it's very light. But that doesn't bake out fully, so it's consumed. Silver oxide is heavier, but does bake out fully. I have a paper from NASA from the 1990s about silver oxide granuals, regenerated (baked out) with a microwave oven. Would you believe a microwave oven is more energy efficient? Duh! ISS currently uses silver oxide for white EMU spacesuits, regenerated with an electro-resistive oven aka toaster oven. Silver oxide is configured as sheet metal. To use a microwave oven, it must be granuals. Navy nuclear submarines use a tank of liquid amine, bubble air through the tank to remove CO2, and bake out periodically. This has a problem in zero-G, the liquid will float away creating a breathing hazard. NASA developed an amine paste based on the Navy's amine. That paste is painted on styrofoam beads. When baking out, ensure you don't heat it so much that you melt the styrofoam. NASA developed an "extended mission life support pallet" for Space Shuttle that fit in the cargo hold. That pallet had styrofoam beads with amine, and extra tanks of oxygen. And the docking port with ISS had a connector so ISS could provide electricity to Shuttle. ISS has large solar arrays, so that provided unlimited power. Amine on styrofoam is lighter than silver oxide, but bulky, large volume. Good for a shuttle or station, but not a spacesuit. On Mars you could use any of these.

Oxygen generator, electrolysis of water: Using a semipermeable membrane allows the tank to work in zero-G. On Mars, that's not an issue, the planet has gravity. Oxygen bubbles will float to the surface.

Sabatier reactor: convert CO2 and H2 into methane and water. This requires high temperature, but it's exothermic. That means it produces heat, so once started it keeps going. Human metabolism converts carbohydrates + O2 into CO2 + water. If you work it out, oxygen generation by electrolysis of water alone only produces half the oxygen that humans need. If you produce oxygen that way, and just run it to produce enough oxygen, that will consume water. The Russian space station Mir just let that happen, shipped up large bags of water. After all, 88.8% of the mass of water is oxygen, and with this system they only had to provide enough water for half the oxygen cosmonauts breathe. The rest of the water came from water recycling: urine filtration and cabin dehumidifier. A Sabatier reactor combines all of the hydrogen from the water electrolysis tank with half of the CO2 removed from cabin air, producing methane and water. This greatly reduces the need for water from Earth. It almost but not quite closes recycling. There's still a need to replace some water. Methane and the other half of CO2 must be dumped in space, any moisture in those gasses are a water loss. Furthermore, moisture in solid human waste (feces) is another water loss.

When Mir was still in space, NASA asked why Russia doesn't just ship oxygen up? Yes, their life support system (without Sabatier) recycles half the O2, but still, why ship water? The answer is tank weight. Oxygen gas requires a heavy metal tank to hold pressurized gas. Water only requires a bag; they use a plastic bag with an outer fabric bag so the plastic doesn't tear. 88.8% of water is oxygen, water plus bag has lower mass than O2 plus metal tank.

Water recycling: urine processing and dehumidifier. Filter to produce potable water.

Direct CO2 electrolysis: convert 80% of CO2 into carbon monoxide (CO) and oxygen. Done over a thin zeolite catalyst; CO2 and CO stay inside the zeolite tube, oxygen passes through due to electricity to the outside. CO2 must be heated over +900°C. Between heat and electricity for electrolysis, this consumes 3 times as much power per unit mass of oxygen vs water electrolysis. Since it consumes 3 times as much power, it's something you want to minimize. Furthermore, this recovers 50% of the oxygen from 80% of the CO2, so total 40% oxygen recovery. Sabatier reactor with water electrolysis recovers 100% of the oxygen. However, this can be used on CO2 that would otherwise be dumped in space. So this can be used to replenish life support recovery losses. The mixture of CO with remaining CO2 dumped in space.

This one has a danger: a crack in the thin zeolite tube will allow CO get into cabin air. When humans breathe carbon monoxide (CO) it binds with hemoglobin. We use hemoglobin in blood to transport oxygen. But CO binds to hemoglobin, and never lets go. Once CO binds, that hemoglobin can no longer transport oxygen. There is no treatment to cure CO poisoning. But red blood cells only last 6 weeks. Our spleen breaks down old and damaged red blood cells, and bone marrow makes new ones. So once exposed to CO, it will take about 6 weeks to recover. A life support system that uses direct CO2 electrolysis must use several small zeolite tubes, each in a separate canister. Each canister must have a CO detector in the O2 outlet stream. If there's any CO at all, shut that unit down. It will have to be replaced.

Human metabolism:
Complex carbohydrates are polymerized sugar. Simple sugar, known as monosaccharide: C6H12O6. Every time two monosaccharids bind, one sugar loses a hydrogen atom, the other a hydroxyl group (OH), which combine to form water (H2O). The free bond of one monosaccharide binds to the other. The first step of human metabolism is to undo this. Humans have enzymes that break complex carbohydrates into simple sugar, adding water back.
Cellular respiration: 1 C6H12O6 + 6 O2 → 6 CO2 + 6 H2O
Plant photosynthesis: 6 CO2 + 6 H2O → 1 C6H12O6 + 6 O2
Water electrolysis: 2 H2O → 2 H2 + 1 O2
Sabatier: 4 H2 + 1 CO2 → 1 CH4 + 2 H2O

Toilet: A new toilet the Russians developed for Mir2 would use vacuum desiccation to extract moisture from feces. This module is now the Russia module Zarya. NASA thought plumbing for the new toilet was too complicated, so insisted they go back to the old toilet, the one for Mir. I imagine after the Columbia accident, NASA wished they had the new toilet.
And some years ago, Johnson Space Center did a study called Advanced Life Support Project. They used an incinerating toilet. This does not require combustion, it can be done with an electro-resistive oven (electric oven).

Backups:
1) When water electrolysis fails, use CO2 electrolysis. It will consume a lot of power, but will produce oxygen.
2) Extract CO2 from Mars atmosphere, use that for CO2 electrolysis.
3) Extract Mars ice, will probably be muddy and salty so filter for pure water, feed that to water electrolysis.
4) If water recycling fails, use CO2 electrolysis for O2, shut down water electrolysis. This means water humans produce metabolism will not be consumed. That assumes you still have some water recycling: eg processing condensate from cabin dehumidifier.

Biological:
I have argued strenuously for greenhouse(s) that use ambient light on Mars. The reason is all the above systems have a single point of failure: power. An ambient light greenhouse is the only life support system that will operate with absolutely no power. Of course a greenhouse will produce food (vegetables, grain, fruit), but also produces oxygen. In fact, NASA studies have shown that if a greenhouse produces all the food for astronauts, it will produce 3 times as much oxygen as they need. On a planet without a breathable atmosphere, excess oxygen is good! Plants will transpire moisture through their leaves, producing humidity in the greenhouse. That humidity will condense on cold windows. A trough along the bottom of windows can collect that water. This produces water that tastes more pure than any filtration system that NASA has devised. The question is how to recycle urine and feces into something that can be used as fertilizer for plants. Yes, you can process Mars dirt to become arable soil. But that still requires water of some kind.

This raises a couple questions. How to process Mars dirt to break down perchlorates. They're toxic, and plants grown in soil with perchlorates become contaminated with those perchlorates. You don't want vegetables contaminated with perchlorate, because that's toxic. Bacteria can break down perchlorate, but you want a faster process. That's one area of research.

Arable soil requires micronutrients, but Mars dirt has that. Fertilizer on Earth is normally K-P-N: potassium-phosphorus-nitrogen. Mars dirt has enough phosphorus, has some potassium but it's low, and no nitrogen at all. At least no nitrogen within detection threshold of instruments on Spirit & Opportunity. Curiosity had instruments 10 times as sensitive, I think Curiosity found a tiny bit of nitrogen in some samples. But not enough, and most samples by Curiosity still had none. We can make ammonium nitrate fertilizer from nitrogen extracted from Mars atmosphere. Yes, ammonium nitrate. That's the white granules that farmers have used for many decades, and people used to use on their lawn before the Oklahoma bombing. You can't be afraid of it, just do it. And potassium fertilizer. The usual source is potassium salt, found where an ancient saltwater sea dried up. It can be found in deposits beneath the Mediterranean Sea, beneath the Great Lakes, etc. There's also a deposit in western North Dakota / eastern Montana, and southern Saskatchewan. (A Canadian province that borders those two states.) And others. On Mars it should be at the bottom of the dried up ocean basin. Until such a deposit is found, we'll have to make do with Mars dirt.

Devising a toilet for a greenhouse on Mars is different than a toilet for a chemical/mechanical life support system. Instead of extracting moisture, you want to process urine and feces for something that can be used as fertilizer for plants. Two basic approaches: grey water sewage processing, or composting toilet. With a composting toilet, you have to ensure to collect urine separately from feces. Current toilet on ISS does that. Urine is left to sit for 6 months, bacteria break down urea to form nitrates that plants can use. Feces must not be contaminated with urine, because it changes which bacteria grow on it. Feces mixed with urine smells like an outhouse. Feces that has never been touched by urine smells like wet soil. Bacteria break down feces to produce compost that can be mixed with soil to produce rich black soil. Composted feces have a lot of potassium. Urine has a lot of nitrogen. Grey water sewage processing allows urine to be mixed with feces, basically a flush toilet. This is called black water. A septic tank uses bacteria to break it down. A carefully controlled series of bacteria breaks down black water into something suitable as fertilizer. That's called grey water. That grey water can be used to fertilize roots of crops, either water the soil or part of the hydroponic solution. Although you may not want to use either composted feces or grey water for root crops like potatoes or carrots. It is suitable for crops where produce grow above ground, like tomatoes, beans, peas, grain, strawberries, etc.

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#9 2021-04-06 12:12:40

louis
Member
From: UK
Registered: 2008-03-24
Posts: 6,921

Re: Settlement design

Hi Noah,

Interesting framework for analysis.

I'm assuming you're looking at the very early stages of a settlement on Mars - let's say the first 10 years.

BASIS

Life Support -

Space X's Mission One will be delivering something like 500 tons, possibly more to the surface.

Essentially they can bring a lot of the requirements with them.

For a six person mission, you could literally bring all the food you need to survive for 4 years (so as to allow for a failed return launch - enabling to await rescue by the next Mission) - that would be about 13 tons. In fact with dehydrated food you could get by on less mass since water can be recycled from urine.

You might even be able to take all the air you need - 115 tons for six people to breathe for 4 years but I think that would be too large an amount to budget for.  So maybe 20 tons of air, to enable you to deal with mechanical failures.

Generally I think we would use ISS style life support equipment as that seems to have worked well.

We've essentially resolved the problems of muscle and bone loss in zero G for extended stays in spacem (through a combination of exercise, space medicine and specialist equipment). While living on Mars I would recommended the pioneers wear weighted suits, head covers and boots to simulate Earth G. 

Radiation is best resolved through use of Mars regolith and/or water/ice over structures, 

Clearly it would be a mistake to have just one centralised life support system. I think you'd want several units, preferable located below ground and spread out so they some distance from each other. This will mean in the event of flooding, meteorite strike or any other catastrophic event there will be a better chance of one unit surviving.

Energy System

I strongly support solar power as the main energy system. Owing to dust storms, this will require some back up. This would take the form of chemical batteries and methane/oxygen to power generators. The Starships will already have powerful onboard batteries to actuate the fins etc. I would recommend taking along something like another 30 tons of batteries.  Methane and oxygen are going to be produced so as to provide the fuel for the return journey, so one can easily tap into that process to create an energy reserve.

Solar power has many advantages including quick and flexible deployment. Also, you will be able to begin manufacturing PV panels on Mars at a very early stage.

Robot cleaners to remove dust from solar panels would be useful.


Materials

For the first few years most habs will be directly imported from Earth. These may include Bigelow-style inflatables, and assembly style habs.

To aid assembly and later construction used of an overarching pressurised hab might be useful.

When it comes to erecting Mars ISRU buildings, I think we should look at:

- Cut and cover (dig a trench with a mini digger and then use steel arches over to create a roof. Line with cement and basalt panels.

- Tunneling. Musk may well be using his Boring technology on Mars to create lots of underground space. This is an efficient way of proceeding but I don't think we want to set too strong a precedent for a troglodyte existence. Tunnelled spaces could be good for farm habs using artificial light - which will predominate in the early years.

- Farm habs could be built into sunny hillsides using pressurised glass frames. It should be possible to manufacture glass at an early stage.

- Farm habs using inflatable plastic domes and have low pressure CO2 environments could work but it will be much more  difficult to manufacture plastic on Mars owing to a paucity of hydrocarbons (as far as we know).



I would consider that as part of life support you need to take plenty of 3D printers, CNC lathes, industria; robots and a range of metal/chemical feedstocks to ensure that the pioneers can make a very wide range of products as necessary.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#10 2021-04-06 12:30:36

tahanson43206
Moderator
Registered: 2018-04-27
Posts: 7,676

Re: Settlement design

For all re new topic ...

It is ** really ** encouraging to see your support for Noah's initiative here....

Please note that I have advised Noah to do a bit of research on each personality he is "meeting" here before reply. 

It may be a while before Noah gets back to each of you, but I'm confident he will.

Some of you (all actually) have delivered posts which require a lot of time and thought to handle as they deserve, so that too will slow down the reply process.

(th)

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#11 2021-04-06 12:33:31

louis
Member
From: UK
Registered: 2008-03-24
Posts: 6,921

Re: Settlement design

ARCHITECTURE

Size

I see no problem with spacious accommodation. An imported 5 ton hab could be pretty spacious to begin with and with 500 tons to play with, you could bring several. As well as sleep space, kitchen and dining area, the settlers will need good gym and medical facilities. As the settlement expands you'll need warehouses and retail areas.

In addition you'll need farm habs, industrial habs, science habs, and transport habs (for garaging and maintenance).

The settlement will be constantly expanding.

You'll need pressurised walkway units, to connect habs.

Layout

The principal concern here will be safety.  It will be important to ensure the Spaceport is located well away from the main settlement - maybe 20 kms away. So that means the Spaceport will be quite a large separated settlement area in itself.

Likewise the industrial and science habs will need to be at some distance from the residential areas.

As the settlement grows we will want to ensure there are what I call Earth-like-Environments for recreation and leisure. These could be created in artificial or natural gorges and could be connected one with another via tunnels, so that eventually people can exercise over miles, even tens of miles on different circuits, including suspended walkways or cycleways.

Farm habs will have to be effectively bio secure areas because you won't want any moulds or similar escaping into the main residential areas.

All the habs should be designed to be robot friendly so that tasks such as cleaning of floors and so on can be conducted with ease by robots. So, stairs will be quite a rare feature I would imagine.

Location

NASA/JPL have already identified six or seven prime landing sites, on the boundary of Arcadia Planitia and Amazonis Planitia.
The information was passed to Space X in response to their requrest.

The sites are suitable because they have fairly flat rock platforms with low dust levels on which Starships could land and within a few 10s of Kms there are covered water ice features which could be accessed with relative ease.

Assuming the water is there I think it is very likely that the Mission One base will become the first city on Mars, because for the first few missions, it will make a lot of sense to return to the same location where you know there is water, where there are abandoned Starships  that can be cannibalised for parts and where you will already have established a working Spaceport . So all the momentum for expansion will be there.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#12 2021-04-06 12:47:45

louis
Member
From: UK
Registered: 2008-03-24
Posts: 6,921

Re: Settlement design

PROCESSES

Building

Robotic cement extrusion is probably the most efficient way to deploy robots for construction purposes. This approach has been demonstrated on Earth. There is no reason why it couldn't be used on Mars but as I mentioned before you might need some kind of overarching construction hab to allow robots and humans to work with relative ease in a pressurised environment.

One thing people sometimes forget about is airlocks which will be absolutely crucial on Mars. You certainly don't want one continuous pressurised space otherwise a single catastrophic event could destroy the whole settlement. Manufacturing airlocks on Mars will be challenging.

Cleaning

I don't think you can design completely clean buildings. You will need to deploy robot cleaners on a constant 24/7 schedule, so as previously indicated design your buildings to be compatible with robot cleaners.  Obviously air conditioning will be very important on Mars. We want to ensure the air is clearn, bacteria free as far as possible, and not a burden on health.

Repairing

Thankfully the weather on Mars is very benign - no high force winds (wind for any given speed is about 5% of the equivalent strength on Earth I believe), no rainstorms, no snowstorms, no thunder and lightning, no hurricans and also little seismic activity. We see on the Moon, where the "weather" is pretty much absent entirely things can just survive in good order for probably centuries or thousands of years.

We have to make sure we use the right materials that can withstand the huge temperature shifts on Mars and also be totally sealed against dust entry (for EVA activity you'll need double air locks with built in shower facilities.

The population is going to be so small on Mars to begin with that I think it will be much more of a throwaway society. If your hab is deficient unpack a new one.

Romans constructed buildings that have lasted 2000 years. If we are building from Mars concrete and cement, stone, basalt slabs and so on, there is no reason why they shouldn't survive v. well.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#13 2021-04-06 15:23:33

louis
Member
From: UK
Registered: 2008-03-24
Posts: 6,921

Re: Settlement design

As I understand it,loss of thermal energy from buildings is slower on Mars because of the low pressure atmosphere - so that is a plus ie you don't have to pump in so much energy to keep it at a given temperature, compared with on Earth. For cooling presumably you have some kind of conductor to the outside?  Or have you got to use a refrigeration process?

Oldfart1939 wrote:

Then Temperature regulation must be added to the LSS topic. Staying warm and unfrozen is of great importance!


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#14 2021-04-06 15:27:20

louis
Member
From: UK
Registered: 2008-03-24
Posts: 6,921

Re: Settlement design

So, without rehearsing all the arguments re solar v nuclear, are you saying that Space X will not be able to establish civilisation on Mars using solar energy as the primary source of energy? Just for the record...

kbd512 wrote:

Energy:

When modern civilization was built on Earth, humanity had cheap and easy access to vast quantities of coal / oil / gas that could be burned in an oxidizing atmosphere, along with a strong but light natural composite material, better known as wood.  Since we don't have any of that on Mars, we need nuclear power.  No part of modern civilization was ultimately built using solar panels and batteries.  NASA can use them successfully because they can afford to spend a million dollars per kilowatt of energy output and their spacecraft are either robotic (and thus have a hibernation mode that doesn't equate to death, unlike humans) or operate in full Sun in a hard vacuum for a significant period of time (such as orbiting the Earth).  Heat engines of various forms were and are the bedrock of technologically advanced human civilizations, and no technologically advanced human civilization operates without them.  Novel yet inefficient and intermittent power sources such as solar panels and wind turbines were and are almost exclusively built using fossil fuels, and lots of them.  They certainly have their uses in an energy-rich environment, but Mars is very energy-poor, in terms of both sunlight and wind.

Since all robots and machine tools require copious quantities of energy, spare parts, and highly skilled technicians to operate and repair them, an absolute minimum of specialized tooling should be required to first produce habitable living spaces.  After the pressurized living spaces have been constructed, then we can experiment with every other inefficient and intermittent power source we can concoct, but not a moment before then.

Initially, every bit of the energy provided and tooling to produce or repair machinery must be imported from Earth, at fantastic energy cost, so the ultimate viability of any particular technology is very closely tied to its ultimate durability.  At present, nuclear reactors are some of the most durable machines that humanity has ever created.  There are no solar panels or wind turbines that have operated continuously for 70+ years, for example, although solar thermal power plants can also achieve the same level of durability as nuclear thermal power plants.  The longest continuous operation of any spacecraft in space was achieved using nuclear decay heat, not solar panels.

Anything that doesn't absolutely require computer-control should be studiously avoided.  The life support and communications systems need to be computer-controlled, but that's about it.  You can repair a worn-out air tool such as a drill, using hand tools.  The same can't be said of a battery-powered drill.  If the battery or electric motor or microchip that controls the battery charge / discharge dies, then the only viable option without access to the factory that produced it, is to replace it.  Home workshop amateurs have been fixing air tools for decades without the benefit of any advanced degrees in electrical engineering or factories.

Unlike virtually all sci-fi movies, all airlocks on actual spacecraft are hand-operated and inward-opening, for good reason.  If it doesn't have a motor or battery or electronics that can fail.  Said "machine" needs to achieve a good seal to hold pressure, but that's it.  If the pressure isn't equalized between the visiting spacecraft and space station module, then a human isn't strong enough to break the seal and kill everyone, whereas a powerful electric motor could.  Building needless failure modes, especially lethal failure modes, into machines is counter-productive and expensive.

The overriding point is this:

Don't create a Rube Goldberg of a device, merely to satisfy an engineer's desire to prove how intricate and complex they can make a simple task.  If a hand-operated bit driver can get the job done acceptably well, then you don't need a battery-powered computer-controlled drill and charger.  Simple machines may never attain the absolute pinnacle of achievable efficiency through electrification and computerization, but they also tend to be very reliable and durable.

Building with less energy and fewer resources:

The most practical construction materials are Sulfur-based concrete bricks made from local Sulfur and aggregates, preferably finely ground, surrounding Aramid fiber-reinforced polymer pressure vessel / liners.  Once locally-produced Basalt fiber-reinforced polymer for locally made composites becomes available, that will likely be the cheapest / most readily available material for pressure vessel construction.

Cleaning:

There's no such thing as a building in a desert environment that requires "almost no cleaning", so don't waste time on impossibilities and instead figure out how to efficiently and effectively clean critical areas in the pressurized spaces.  This is a frontier environment, not a clean room.  The Navy cleans their ships at least once per day, even when they're hundreds of miles from the nearest land.  Despite that fact, the ships are still filthy, which is why they're cleaned once per day.  You can and should do your best to "dust off" prior to coming into the habitat module, but that's as far as that goes.  Outside of a clean room environment, dust / dirt / grime is simply a part of life, and people need to accept that.

Repairing:

The fiber-reinforced plastic pressure vessel liners can be repaired in a matter of seconds to minutes, but rapid repair (mere minutes to a couple of hours) is not possible using traditional construction materials (bricks / beams- material doesn't matter / windows; but rapid replacement could be feasible, given a sufficient stock of spares), so focus fabrication efforts on producing smooth / dimensionally accurate bricks to surround the pressure vessel, along with enough spare windows and bricks to replace any that get damaged.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#15 2021-04-06 15:38:21

louis
Member
From: UK
Registered: 2008-03-24
Posts: 6,921

Re: Settlement design

Interesting post, Robert.

Some points/queries:

1. Re perchlorates - my understanding is these are formed at the surface. If you dig down deep enough in areas where there are say alluvial deposits dating back millions of years, don't you eventually come to "clean" soil.

2. Wouldn't it make sense to use solar reflectors to enhance ambient light farming on Mars. On Mars - unlike on Earth - simple light structures won't be battered by high winds, blown over, rained on or otherwise be damaged. So mylar type reflectors could be manufactured on Mars and angled so as to deliver additional solar energy to the greenhouses.

3. What buffer gases would you recommend we use on Mars when creating analogue air. I can see oxygen production being a fairly easy task to accomplish and adding a little CO2 shouldn't be a problem,  but what inert gases would we use. Do we have readily available sources of nitrogen and argon?


RobertDyck wrote:

Did you want answers? First life support. I see multiple life support systems, configured so you can mix-and-match components. That gives options should equipment fail. On a planet with no breathable atmosphere, a robust life support system with multiple backups is necessary.

Chemical/Mechanical based on ISS: electrolysis of water
Regenerable CO2 sorbent: That means a fan to blow cabin/habitat air through a sorbent, which will absorb/adsorb CO2. Periodically the sorbent is "baked out". The CO2 released will be compressed, stored in a pressure cylinder. Mercury/Gemini/Apollo used lithium hydroxide (LiOH) because it's very light. But that doesn't bake out fully, so it's consumed. Silver oxide is heavier, but does bake out fully. I have a paper from NASA from the 1990s about silver oxide granuals, regenerated (baked out) with a microwave oven. Would you believe a microwave oven is more energy efficient? Duh! ISS currently uses silver oxide for white EMU spacesuits, regenerated with an electro-resistive oven aka toaster oven. Silver oxide is configured as sheet metal. To use a microwave oven, it must be granuals. Navy nuclear submarines use a tank of liquid amine, bubble air through the tank to remove CO2, and bake out periodically. This has a problem in zero-G, the liquid will float away creating a breathing hazard. NASA developed an amine paste based on the Navy's amine. That paste is painted on styrofoam beads. When baking out, ensure you don't heat it so much that you melt the styrofoam. NASA developed an "extended mission life support pallet" for Space Shuttle that fit in the cargo hold. That pallet had styrofoam beads with amine, and extra tanks of oxygen. And the docking port with ISS had a connector so ISS could provide electricity to Shuttle. ISS has large solar arrays, so that provided unlimited power. Amine on styrofoam is lighter than silver oxide, but bulky, large volume. Good for a shuttle or station, but not a spacesuit. On Mars you could use any of these.

Oxygen generator, electrolysis of water: Using a semipermeable membrane allows the tank to work in zero-G. On Mars, that's not an issue, the planet has gravity. Oxygen bubbles will float to the surface.

Sabatier reactor: convert CO2 and H2 into methane and water. This requires high temperature, but it's exothermic. That means it produces heat, so once started it keeps going. Human metabolism converts carbohydrates + O2 into CO2 + water. If you work it out, oxygen generation by electrolysis of water alone only produces half the oxygen that humans need. If you produce oxygen that way, and just run it to produce enough oxygen, that will consume water. The Russian space station Mir just let that happen, shipped up large bags of water. After all, 88.8% of the mass of water is oxygen, and with this system they only had to provide enough water for half the oxygen cosmonauts breathe. The rest of the water came from water recycling: urine filtration and cabin dehumidifier. A Sabatier reactor combines all of the hydrogen from the water electrolysis tank with half of the CO2 removed from cabin air, producing methane and water. This greatly reduces the need for water from Earth. It almost but not quite closes recycling. There's still a need to replace some water. Methane and the other half of CO2 must be dumped in space, any moisture in those gasses are a water loss. Furthermore, moisture in solid human waste (feces) is another water loss.

When Mir was still in space, NASA asked why Russia doesn't just ship oxygen up? Yes, their life support system (without Sabatier) recycles half the O2, but still, why ship water? The answer is tank weight. Oxygen gas requires a heavy metal tank to hold pressurized gas. Water only requires a bag; they use a plastic bag with an outer fabric bag so the plastic doesn't tear. 88.8% of water is oxygen, water plus bag has lower mass than O2 plus metal tank.

Water recycling: urine processing and dehumidifier. Filter to produce potable water.

Direct CO2 electrolysis: convert 80% of CO2 into carbon monoxide (CO) and oxygen. Done over a thin zeolite catalyst; CO2 and CO stay inside the zeolite tube, oxygen passes through due to electricity to the outside. CO2 must be heated over +900°C. Between heat and electricity for electrolysis, this consumes 3 times as much power per unit mass of oxygen vs water electrolysis. Since it consumes 3 times as much power, it's something you want to minimize. Furthermore, this recovers 50% of the oxygen from 80% of the CO2, so total 40% oxygen recovery. Sabatier reactor with water electrolysis recovers 100% of the oxygen. However, this can be used on CO2 that would otherwise be dumped in space. So this can be used to replenish life support recovery losses. The mixture of CO with remaining CO2 dumped in space.

This one has a danger: a crack in the thin zeolite tube will allow CO get into cabin air. When humans breathe carbon monoxide (CO) it binds with hemoglobin. We use hemoglobin in blood to transport oxygen. But CO binds to hemoglobin, and never lets go. Once CO binds, that hemoglobin can no longer transport oxygen. There is no treatment to cure CO poisoning. But red blood cells only last 6 weeks. Our spleen breaks down old and damaged red blood cells, and bone marrow makes new ones. So once exposed to CO, it will take about 6 weeks to recover. A life support system that uses direct CO2 electrolysis must use several small zeolite tubes, each in a separate canister. Each canister must have a CO detector in the O2 outlet stream. If there's any CO at all, shut that unit down. It will have to be replaced.

Human metabolism:
Complex carbohydrates are polymerized sugar. Simple sugar, known as monosaccharide: C6H12O6. Every time two monosaccharids bind, one sugar loses a hydrogen atom, the other a hydroxyl group (OH), which combine to form water (H2O). The free bond of one monosaccharide binds to the other. The first step of human metabolism is to undo this. Humans have enzymes that break complex carbohydrates into simple sugar, adding water back.
Cellular respiration: 1 C6H12O6 + 6 O2 → 6 CO2 + 6 H2O
Plant photosynthesis: 6 CO2 + 6 H2O → 1 C6H12O6 + 6 O2
Water electrolysis: 2 H2O → 2 H2 + 1 O2
Sabatier: 4 H2 + 1 CO2 → 1 CH4 + 2 H2O

Toilet: A new toilet the Russians developed for Mir2 would use vacuum desiccation to extract moisture from feces. This module is now the Russia module Zarya. NASA thought plumbing for the new toilet was too complicated, so insisted they go back to the old toilet, the one for Mir. I imagine after the Columbia accident, NASA wished they had the new toilet.
And some years ago, Johnson Space Center did a study called Advanced Life Support Project. They used an incinerating toilet. This does not require combustion, it can be done with an electro-resistive oven (electric oven).

Backups:
1) When water electrolysis fails, use CO2 electrolysis. It will consume a lot of power, but will produce oxygen.
2) Extract CO2 from Mars atmosphere, use that for CO2 electrolysis.
3) Extract Mars ice, will probably be muddy and salty so filter for pure water, feed that to water electrolysis.
4) If water recycling fails, use CO2 electrolysis for O2, shut down water electrolysis. This means water humans produce metabolism will not be consumed. That assumes you still have some water recycling: eg processing condensate from cabin dehumidifier.

Biological:
I have argued strenuously for greenhouse(s) that use ambient light on Mars. The reason is all the above systems have a single point of failure: power. An ambient light greenhouse is the only life support system that will operate with absolutely no power. Of course a greenhouse will produce food (vegetables, grain, fruit), but also produces oxygen. In fact, NASA studies have shown that if a greenhouse produces all the food for astronauts, it will produce 3 times as much oxygen as they need. On a planet without a breathable atmosphere, excess oxygen is good! Plants will transpire moisture through their leaves, producing humidity in the greenhouse. That humidity will condense on cold windows. A trough along the bottom of windows can collect that water. This produces water that tastes more pure than any filtration system that NASA has devised. The question is how to recycle urine and feces into something that can be used as fertilizer for plants. Yes, you can process Mars dirt to become arable soil. But that still requires water of some kind.

This raises a couple questions. How to process Mars dirt to break down perchlorates. They're toxic, and plants grown in soil with perchlorates become contaminated with those perchlorates. You don't want vegetables contaminated with perchlorate, because that's toxic. Bacteria can break down perchlorate, but you want a faster process. That's one area of research.

Arable soil requires micronutrients, but Mars dirt has that. Fertilizer on Earth is normally K-P-N: potassium-phosphorus-nitrogen. Mars dirt has enough phosphorus, has some potassium but it's low, and no nitrogen at all. At least no nitrogen within detection threshold of instruments on Spirit & Opportunity. Curiosity had instruments 10 times as sensitive, I think Curiosity found a tiny bit of nitrogen in some samples. But not enough, and most samples by Curiosity still had none. We can make ammonium nitrate fertilizer from nitrogen extracted from Mars atmosphere. Yes, ammonium nitrate. That's the white granules that farmers have used for many decades, and people used to use on their lawn before the Oklahoma bombing. You can't be afraid of it, just do it. And potassium fertilizer. The usual source is potassium salt, found where an ancient saltwater sea dried up. It can be found in deposits beneath the Mediterranean Sea, beneath the Great Lakes, etc. There's also a deposit in western North Dakota / eastern Montana, and southern Saskatchewan. (A Canadian province that borders those two states.) And others. On Mars it should be at the bottom of the dried up ocean basin. Until such a deposit is found, we'll have to make do with Mars dirt.

Devising a toilet for a greenhouse on Mars is different than a toilet for a chemical/mechanical life support system. Instead of extracting moisture, you want to process urine and feces for something that can be used as fertilizer for plants. Two basic approaches: grey water sewage processing, or composting toilet. With a composting toilet, you have to ensure to collect urine separately from feces. Current toilet on ISS does that. Urine is left to sit for 6 months, bacteria break down urea to form nitrates that plants can use. Feces must not be contaminated with urine, because it changes which bacteria grow on it. Feces mixed with urine smells like an outhouse. Feces that has never been touched by urine smells like wet soil. Bacteria break down feces to produce compost that can be mixed with soil to produce rich black soil. Composted feces have a lot of potassium. Urine has a lot of nitrogen. Grey water sewage processing allows urine to be mixed with feces, basically a flush toilet. This is called black water. A septic tank uses bacteria to break it down. A carefully controlled series of bacteria breaks down black water into something suitable as fertilizer. That's called grey water. That grey water can be used to fertilize roots of crops, either water the soil or part of the hydroponic solution. Although you may not want to use either composted feces or grey water for root crops like potatoes or carrots. It is suitable for crops where produce grow above ground, like tomatoes, beans, peas, grain, strawberries, etc.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#16 2021-04-06 16:35:13

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 6,788
Website

Re: Settlement design

louis wrote:

1. Re perchlorates - my understanding is these are formed at the surface. If you dig down deep enough in areas where there are say alluvial deposits dating back millions of years, don't you eventually come to "clean" soil.

Ok. Of course I want to see a mission dig down to prove that.

louis wrote:

2. Wouldn't it make sense to use solar reflectors to enhance ambient light farming on Mars. On Mars - unlike on Earth - simple light structures won't be battered by high winds, blown over, rained on or otherwise be damaged. So mylar type reflectors could be manufactured on Mars and angled so as to deliver additional solar energy to the greenhouses.

I have posted about that before. Certain crops thrive in shade on Earth, including many vegetables. They can use ambient light on Mars, no reflector. Other crops such as grain require full sun. They could benefit from reflectors. Mirrors should have some substance to withstand Mars wind, but that wind is incredibly weak so it won't require much.

My design for a Mars greenhouse is long and narrow. Twice as wide as it is high, with the long side oriented perfectly east-west. A mirror along both sides, from one end to the other. With mirror from ground level, or lowest level of crops in the greenhouse, to the same height as roof of the greenhouse. So direct sunlight plus reflected provides exactly double illumination. Long and narrow because as the sun rises in the east, sunlight will reflect westward but still within the greenhouse. When the sun sets in the west, sunlight will reflect eastward but again still within the greenhouse. So mirrors do not have to track the Sun. Angle will have to be adjusted for season, but that only requires 1° angle change once every 14 Mars solar days (sols). That could be done automatically by a worm screw, or a worker in a spacesuit could move a support rod to the next notch. Only required every second Monday (or pick day of the week).

louis wrote:

3. What buffer gases would you recommend we use on Mars when creating analogue air. I can see oxygen production being a fairly easy task to accomplish and adding a little CO2 shouldn't be a problem,  but what inert gases would we use. Do we have readily available sources of nitrogen and argon?

I have also posted my proposal for a device to harvest "diluent gas" from Mars atmosphere. It would produce nitrogen/argon mix, with the same proportions as Mars atmosphere. Why bother separating them? According to Viking 2 lander from late 1976, Mars atmosphere is 2.7% nitrogen, 1.6% argon. Exact amounts measured by modern landers & rovers vary a little, but my device would remove CO2, decompose CO and O3, keep the rest. Not intended to remove moisture, but will happen, can't avoid it. If you start with what Viking 2 measured, result would be:
61.0% N2
36.1% Ar
2.1% O2
0.75% CO2
--- trace gasses:
0.0056% Ne
0.00068% Kr
0.00018% Xe

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#17 2021-04-06 17:50:14

louis
Member
From: UK
Registered: 2008-03-24
Posts: 6,921

Re: Settlement design

Thanks for the answers Robert!

I am sure we are all looking forward to the pioneers on Mars digging down into the regolith to see how far the perchlorates persist. From everything I have read, there is no chance of perchlorates forming below say one or two metres, but whether perchlorates gradually move down under gravity, ice melt or other processes, I guess is an open question.

Use of mirrors within the greenhouse structure sounds interesting. Is this ever done on Earth? I ask because I'm curious as to why it hasn't been tried if it is effective.

The landing sites proposed to Space X by NASA/JPL are not actually that far off the optimal solar irradiation zone (much farther north on Mars because of the planetary "wobble"), so we although overall solar radiation may be on Mars with a two Earth year season effectively and farming at what would be the equator we may be quite a lot closer to farming in temperate zones on Earth than people realise.

So if I understand you right on creating an analogue air on Mars, we should simply concentrate nitrogen and argon without worrying about replicating the proportions in Earth air...?


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#18 2021-04-06 18:47:51

kbd512
Administrator
Registered: 2015-01-02
Posts: 4,737

Re: Settlement design

louis wrote:

So, without rehearsing all the arguments re solar v nuclear, are you saying that Space X will not be able to establish civilisation on Mars using solar energy as the primary source of energy? Just for the record...

Louis,

Is the goal is to create a self-sustaining second branch of human civilization on Mars, a city with at least a million people, that also pays for itself?

If so, then yes, that's exactly what I'm stating.

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#19 2021-04-06 19:02:48

louis
Member
From: UK
Registered: 2008-03-24
Posts: 6,921

Re: Settlement design

Thanks for clarifying. Yes of course - Musk's goal is certainly to create a milliion person city.

kbd512 wrote:
louis wrote:

So, without rehearsing all the arguments re solar v nuclear, are you saying that Space X will not be able to establish civilisation on Mars using solar energy as the primary source of energy? Just for the record...

Louis,

Is the goal is to create a self-sustaining second branch of human civilization on Mars, a city with at least a million people, that also pays for itself?

If so, then yes, that's exactly what I'm stating.


Let's Go to Mars...Google on: Fast Track to Mars blogspot.com

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#20 2021-04-06 20:08:51

SpaceNut
Administrator
From: New Hampshire
Registered: 2004-07-22
Posts: 23,401

Re: Settlement design

This may be mentioned above by others

Life support also needs atmospheric scrubbers and dehumidification

Energy is not just about making but save and storing it for when your systems go down and can not function ex dust storms for solar or oxygen making from Mars atmosphere when its that bad

Insitu materials need equipment for mining and processing not just making stuff from it by robotics.

The larger a structure is the harder it is to build but we will need room to grow and its not easy to stay in a building mode. A key thing of making a building is to give ways to reduce risk as to isolate work zones, processing equipment and many more semi hazardous work areas from main population areas via air locks, shielding doors for blasts and fires. Safe haven pod areas if such things happen.


Location is tied to what is the most important resource that man must find from insitu materials of which I suspect its water as recycling does not last due to efficiencies of equipment.

If telerobot's are not possible a supply of space suits and protective over covering to make them last longer would seem to be a must.

BY the way welcome to NewMars Noah....

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#21 2021-04-06 22:33:10

RobertDyck
Moderator
From: Winnipeg, Canada
Registered: 2002-08-20
Posts: 6,788
Website

Re: Settlement design

louis wrote:

Use of mirrors within the greenhouse structure sounds interesting. Is this ever done on Earth? I ask because I'm curious as to why it hasn't been tried if it is effective.

Woo hoo! Someone has created an image on Marspedia. These mirrors are a little larger than I described, but eh! Close enough!
MultipleMirrorsForGreenhouse.png
People have looked at mirrors to increase illumination for a greenhouse. I was thinking of building a walipini in my backyard. That's a sunken greenhouse. The purpose is to extend growing season. Winters here are too cold for it to work year round, but using ground warmth could allow earlier planting, and could extend growing season later into the fall. But sunlight is an issue. In winter the sun gets low to the horizon. So I was thinking of reflectors. Since my yard is small, the only place a walipini would fit is beside the garage. A mirror on the garage wall beside the sunken greenhouse could reflect light down into it. And the back wall could be covered in mirror. So when the sun is low, sunlight could reflect down into the sunken greenhouse. You can buy "self adhesive mirror sheets" that are affordable.
71QHw1L2UCL._AC_UL160_SR160,160_.jpg

louis wrote:

So if I understand you right on creating an analogue air on Mars, we should simply concentrate nitrogen and argon without worrying about replicating the proportions in Earth air...?

Humans require pressure and oxygen. Anything else is just to reduce fire hazard, and increase pressure further to make cooking easier. Noble gasses do not react with anything, they're just there: Ar, Ne, Kr, Xe. Nitrogen doesn't do anything for humans; again it reduces combustion rate by getting in the way of oxygen so reduced fire hazard. Bacteria can convert atmospheric nitrogen plus water into nitrates that plants can use as nitrogen fertilizer. But it doesn't do anything for humans. Earth's atmosphere has all these same gasses, just different concentrations.
220px-Atmosphere_gas_proportions.svg.png

Skylab used 5.0 psi total pressure with 60% O2 / 40% N2. That resulted in 3.0 psi partial pressure O2, 2.0 psi partial pressure N2. Earth has 20.946% O2 and pressure at sea level is 14.69595 psi, multiplying that's 3.0782 psi partial pressure O2. So Skylab partial pressure O2 was practically identical to Earth sea level. Mars Direct recommended using exactly that. I'm suggesting slightly higher pressure.

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#22 2021-04-07 03:29:15

Noah
Member
From: Zurich (Switzerland)
Registered: 2020-07-28
Posts: 38

Re: Settlement design

Oldfart1939 wrote:

Then Temperature regulation must be added to the LSS topic. Staying warm and unfrozen is of great importance!

Thanks, it is a very important part of the LSS! I have implemented the suggestion.

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#23 2021-04-07 03:32:58

Noah
Member
From: Zurich (Switzerland)
Registered: 2020-07-28
Posts: 38

Re: Settlement design

kbd512 wrote:

Since we don't have any of that on Mars, we need nuclear power.  No part of modern civilization was ultimately built using solar panels and batteries

Attractive approach to go back in history.
I agree that it would be risky to build a city with only solar panels. A mix of different types of energy supply looks interesting. To diversify is a good concept in most cases.
E.g. nuclear power and solar cells.

kbd512 wrote:

Don't create a Rube Goldberg of a device, merely to satisfy an engineer's desire to prove how intricate and complex they can make a simple task.  If a hand-operated bit driver can get the job done acceptably well, then you don't need a battery-powered computer-controlled drill and charger.  Simple machines may never attain the absolute pinnacle of achievable efficiency through electrification and computerization, but they also tend to be very reliable and durable.

Keep thinks simple. I absolutely agree!

kbd512 wrote:

The most practical construction materials are Sulfur-based concrete bricks made from local Sulfur and aggregates,

For the building, the material is the *most important * factor, it will affect the construction process, energy consumption, LSS ...
I will take a closer look at the sulfur based concrete.

Cleaning

I removed the question with "almost no cleaning" and implemented your suggestion.

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#24 2021-04-07 04:04:43

Noah
Member
From: Zurich (Switzerland)
Registered: 2020-07-28
Posts: 38

Re: Settlement design

Hello everyone!

Thank you very much for all the comments!
I am currently working on an overall concept for a settlement design and will take all your suggestions into consideration.
(The concept should be ready around July and I'm already looking forward to your opinions).

Short introduction about me:
I'm Noah, 20 years old and from Germany. I am currently studying physics at the ETH in Switzerland. In the past I did several architecture internships and participated in an architecture competition.

My English is not perfect and suggestions for improvement are ALWAYS welcome.

Last edited by Noah (2021-04-07 04:10:08)

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#25 2021-04-07 04:08:55

Noah
Member
From: Zurich (Switzerland)
Registered: 2020-07-28
Posts: 38

Re: Settlement design

Hello Louis!
Thanks for the comments and also for the good structure. Nice to read.

louis wrote:

I'm assuming you're looking at the very early stages of a settlement on Mars - let's say the first 10 years.

Yes, I forgot the trivial but important information.

louis wrote:

Space X's Mission One will be delivering something like 500 tons, possibly more to the surface.

I thought it was about 100 metric tons per spacecraft. So 200 t on the first trip and another 200 t 26 months later when the crew arrives (total = 400 tons). 
Or did they update the design of the starship? 

louis wrote:

I would consider that as part of life support you need to take plenty of 3D printers, (…)

3D printers are so amazing. I just bought on a few weeks ago and it’s unbelievable how many possibilities you have with a 3D printer. I am currently building a small rocket with my friends and the 3D printer is a great help.

louis wrote:

(…) and also be totally sealed against dust entry (for EVA activity you'll need double air locks with built in shower facilities.

I have seen some concepts where the EVA suits are stored outside and the suits themselves have the airlock built in. This is because some dust particles are so tiny that they cannot be filtered and would be deposited in the lungs.

Last edited by Noah (2021-04-07 11:35:51)

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