Mining Mars for a self-sufficent colony

[Darnok]

How much energy we need to mine enough resources to get 1 ton of steel on Mars?
How much energy (and oxygen) do we need to get 1 ton of steel on Mars?
How much food we need to feed people, while they are mining and making this 1 ton of steel?
How much space and other resources (energy, water etc etc) we need to grown that amount of food on Mars?

 

[Spaceception]

6 minutes ago, Darnok said:

How much energy we need to mine enough resources to get 1 ton of steel on Mars?
How much energy (and oxygen) do we need to get 1 ton of steel on Mars?
How much food we need to feed people, while they are mining and making this 1 ton of steel?
How much space and other resources (energy, water etc etc) we need to grown that amount of food on Mars?

 

Depends, if it's all manpower, a lot, if there's robots, it'll still be a lot, but humans won't need to expend as much energy, so it'll come from mostly Solar, and not calories, but you also have to factor in Mars' gravity, which could make things easier for both the robots and people, as the lighter weight could save significant amounts of energy on both sides.

[Darnok]

17 minutes ago, Spaceception said:

Depends, if it's all manpower, a lot, if there's robots, it'll still be a lot, but humans won't need to expend as much energy, so it'll come from mostly Solar, and not calories, but you also have to factor in Mars' gravity, which could make things easier for both the robots and people, as the lighter weight could save significant amounts of energy on both sides.

Sure, but when you want to send astronauts to mine... it gets bit funny

Also if it is all about solar power then you need to have lots of space on ground for them (Mars is further than Earth).
And you also need ability to replicate broken solar panels...
which means you need ability to replicate advanced machinery that can produce solar panels...
which means you need many mines with different kinds of metal...
which means you need ground vehicles and logistics...
which means you need many bases and ability to replicate broken bases (repairing stations for vehicles for example) and broken vehicles...
which means you need more advanced machines to produce pressurized base segments and pressurized electrical vehicles

And we didn't even started to talk about how you are going to grow plants on Mars... in amounts large enough you can feed all hard working miners.
Or about how to get enough air (its not pure oxygen) to re-pressurize bases and vehicles, not to mention that people needs to breathe and some of your production lanes are going to burn oxygen and we are talking about self-sufficient base.

Edited February 23, 2016 by Darnok

[Spaceception]

1 hour ago, Darnok said:

Sure, but when you want to send astronauts to mine... it gets bit funny

Also if it is all about solar power then you need to have lots of space on ground for them (Mars is further than Earth).
And you also need ability to replicate broken solar panels...
which means you need ability to replicate advanced machinery that can produce solar panels...
which means you need many mines with different kinds of metal...
which means you need ground vehicles and logistics...
which means you need many bases and ability to replicate broken bases (repairing stations for vehicles for example) and broken vehicles...
which means you need more advanced machines to produce pressurized base segments and pressurized electrical vehicles

And we didn't even started to talk about how you are going to grow plants on Mars... in amounts large enough you can feed all hard working miners.
Or about how to get enough air (its not pure oxygen) to re-pressurize bases and vehicles, not to mention that people needs to breathe and some of your production lanes are going to burn oxygen and we are talking about self-sufficient base.

All good points, and in a sci-fi world, we make highly efficient self repairing solar panels, irl, we make redundant systems and backups (And a flat area to put them).

Hydroponics can grow food, and replace CO2 with O2, plus, since Mars puny atmosphere is almost 100% CO2, you can suck in the outside air, run it through an oxygenator, and poof! Breathable air, humans recycle N2 pretty well, so that's not to much of a problem, we mostly need to keep CO2 levels down.

Edited February 23, 2016 by Spaceception

[Darnok]

1 hour ago, Spaceception said:

All good points, and in a sci-fi world, we make highly efficient self repairing solar panels, irl, we make redundant systems and backups (And a flat area to put them).

Hydroponics can grow food, and replace CO2 with O2, plus, since Mars puny atmosphere is almost 100% CO2, you can suck in the outside air, run it through an oxygenator, and poof! Breathable air, humans recycle N2 pretty well, so that's not to much of a problem, we mostly need to keep CO2 levels down.

Redundancy and backups won't give you self-sufficiency, it will only delay "the end" in this case.

There is one more point... we need ability to replicate broken humans

And as far as I know we have no idea if that is possible outside of Earth (on Venus that shouldn't be problem... unless we need magnetic field on some level of our life, but that is topic for different thread).

Well I see no chance to make such colony on Mars for next 50+ years

[insert_name]

1 hour ago, Darnok said:

1.Redundancy and backups won't give you self-sufficiency, it will only delay "the end" in this case.

2.There is one more point... we need ability to replicate broken humans

And as far as I know we have no idea if that is possible outside of Earth (on Venus that shouldn't be problem... unless we need magnetic field on some level of our life, but that is topic for different thread).

Well I see no chance to make such colony on Mars for next 50+ years

1.we only need to delay the end long enough to manufacture the replacements

2. we just need to see whether reproduction works on mars, preferably with animals before we try humans. we have a sample size of 1 for how gravity affects human reproduction, and the rest is theoretical at this point

[Hannu2]

23 hours ago, Spaceception said:

Okay, drop all criticisms/pessimism you may have for Mars colonies, or a SpaceX Mars colony, as this is a thought experiment; Here are the questions

1: Where would be the best place for the colony to be?

2: What materials would they mine?

3: What would the city look like and function?

4: How long would a Martian city take to build?

1. I do not know much about martian geology and I think that nobody knows. There must be much basic investigation before we know what are best position for cities or mines.

2. First things are soil materials for building and concrete manufacturing. After that iron and aluminium.

3. Difficult to say. Probably somewhat like cities on Earth because they are practical forms and people are used to it.

4. 1000 years before it can be called as a city. Maybe then it can be a self sufficient community with agriculture (on areas around city), mining, industry, services, administration and tens of thousands of people.

[KSK]

I'm going to add a fifth question to OP's list. What is the minimum level of technology needed to survive on Mars once you get there? 

I'm thinking that the simpler the technology required, the simpler the facilities needed to repair and replace that technology and therefore, the quicker your colony becomes self-sustaining.

[kunok]

20 hours ago, Spaceception said:

Alright, I edited the OP, but to be fair, we went from satellites in really low LEO to people on the Moon in about 12 years.

And yet we only can support 9 humans in low orbit with regular supplies even 60 years later. Maybe it's because it's not comparable at all? Human presence it's very hard, we needed a lot of stations and research to get to this level of ours life supports systems, and we will need betters. The moon was based in supplies, not in close life support systems, systems that will be needed for a simple outpost outside earth, and colonization and self-sufficiency is even another level.

17 hours ago, Spaceception said:

Since when did this discussion talk about MO? I know I'm sometimes really optimistic, but MO is WAY too optimistic, for 4 things, 1st: the amount of people they want to send to Mars per year is way to low for colonization, 2nd: The amount of people they're employing is ridiculously low, 3rd, while the budget may work with rapid-reusable rockets (If you perhaps double it for wiggle room), they have absolutely no way of funding it, and 4th, on the note of rapid-reusable rockets, even if they're around by the time they're ready to launch, (Which they probably will be), they have no way of guaranteeing that they'll be able to get a rocket launch every 2 years, much less rescue ships in case something goes wrong (Which it probably will).

Here is the funny part: your plan is a lot less realistic that the Mars one's one and your points are very applicable to your space X based plan, every one. And I know that Mars One is or a scam or an absurdly optimistic plan.

And you don't look like you want to discuss why is pure fantasy.

I came here cheerful and I was trying to be constructive and helpful proposing a long term plan based in necessary research. But if we say what are bad in your plan you only put this in your op "Okay, drop all criticisms/pessimism you may have for Mars colonies, or a SpaceX Mars colony, as this is a thought experiment; Here are the questions" not fixing anything at all of your plan. And now instead of cheerful I'm just tired.

21 hours ago, Spaceception said:

Alright, I edited the OP, but to be fair, we went from satellites in really low LEO to people on the Moon in about 12 years.

And yet we only can support 9 humans in low orbit with regular supplies even 60 years later. Maybe it's because it's not comparable at all? Human presence it's very hard, we needed a lot of stations and research to get to this level of ours life supports systems, and we will need betters. The moon was based in supplies, not in close life support systems, systems that will be needed for a simple outpost outside earth, and colonization and self-sufficiency is even another level.

18 hours ago, Spaceception said:

Since when did this discussion talk about MO? I know I'm sometimes really optimistic, but MO is WAY too optimistic, for 4 things, 1st: the amount of people they want to send to Mars per year is way to low for colonization, 2nd: The amount of people they're employing is ridiculously low, 3rd, while the budget may work with rapid-reusable rockets (If you perhaps double it for wiggle room), they have absolutely no way of funding it, and 4th, on the note of rapid-reusable rockets, even if they're around by the time they're ready to launch, (Which they probably will be), they have no way of guaranteeing that they'll be able to get a rocket launch every 2 years, much less rescue ships in case something goes wrong (Which it probably will).

Here is the funny part: your plan is a lot less realistic that the Mars one's one and your points are very applicable to your space X based plan, every one. And I know that Mars One is or a scam or an absurdly optimistic plan.

And you don't look like you want to discuss why is pure fantasy.

I came here cheerful and I was trying to be constructive and helpful proposing a long term plan based in necessary research. But if we say what are bad in your plan you only put this in your op "Okay, drop all criticisms/pessimism you may have for Mars colonies, or a SpaceX Mars colony, as this is a thought experiment; Here are the questions" not fixing anything at all of your plan. And now instead of cheerful I'm just tired.

2 minutes ago, KSK said:

I'm going to add a fifth question to OP's list. What is the minimum level of technology needed to survive on Mars once you get there? 

I'm thinking that the simpler the technology required, the simpler the facilities needed to repair and replace that technology and therefore, the quicker your colony becomes self-sustaining.

For an airtight airlock manufacturing? Actual tech level. You don't make an airtight seal without high tech, same for an space suit.

[fredinno]

On February 22, 2016 at 0:25 PM, Spaceception said:

Please note: This topic assumes SpaceX lands 1000 people on Mars (Via 10  MCT's) in 2030, and continues doing so every 2 years until they can increase launches

Alright, imagine this: The newest arrival of Humans recently landed on Mars in ____ (Whatever date you feel is realistic), but this time, with an additional 6th (Unmanned) ship, that unmanned ship contains equipment for use in mining, and 4 of the 10 ships has miners, SpaceX, before the 10 ships landed on Mars, said that the colonists will be required to begin mining materials from and under the martian regolith for the construction of a Martian city that will also begin to make the colony self-sufficient.

Okay, drop all criticisms/pessimism you may have for Mars colonies, or a SpaceX Mars colony, as this is a thought experiment; Here are the questions

1: Where would be the best place for the colony to be?

2: What materials would they mine?

3: What would the city look like and function?

4: How long would a Martian city take to build?

5: For further discussions on a similar topic, go here;

My colony would placed in the depths of Valles Marineris. Landing technology can land there (it was proposed for Mars 2020) and would be able to mine lots of minerals released from the volcanism, while benefiting from its lower elevation. It would likely take a century for any martian city to build up to a sustainable colony.

4 hours ago, Spaceception said:

All good points, and in a sci-fi world, we make highly efficient self repairing solar panels, irl, we make redundant systems and backups (And a flat area to put them).

Hydroponics can grow food, and replace CO2 with O2, plus, since Mars puny atmosphere is almost 100% CO2, you can suck in the outside air, run it through an oxygenator, and poof! Breathable air, humans recycle N2 pretty well, so that's not to much of a problem, we mostly need to keep CO2 levels down.

Yeah, but I thought this is not supposed to be a sci-fi world, this is a forum for SCIENCE.

[fredinno]

19 hours ago, Spaceception said:

That was only because the Gov't didn't want to fund the Apollo program anymore since it was getting to expensive for their liking, we could've easily put a colony on the Moon by 1990-2010 (Maybe even before) if we continued the Apollo program.

Also, isn't it '=/='?

EDIT: Around Apollo 20, NASA planned to send astronauts to the Moon for Months at a time, which would've helped with Lunar colonization efforts.

Yeah, a base is a long way from a colony.

18 hours ago, tater said:

I wasn't suggesting this was the exactly the same as MO, I was saying that in their critique of MO, the MIT guys provided useful benchmarks in units of 4 people and D2 landings on the martian surface. Using their data, which seems reasonable, their logistical train for 4 people was about 4 D2 landings (2 mt useful payload each). MCT claims 100 mt to the surface (unsure if this is payload or includes the craft, let's say payload for kicks), that's 1 mt per person. Apparently improved life support from ISS extrapolates to another mt per year of parts, etc, per person. So you need 25 launches for the 1st 1000 people, and 20 every other year just to support them, plus the new 1000 people.

The MO counter-arguments still apply, though we might get some economies of scale for LS... or more people might wear out LS faster than our tiny ISS experiments have shown... who knows?

So it's sort of the same thing. Logistics is all that matters for an endeavor of this kind. I'm assuming the MCT is a thing, and it can launch as often as needed. I'll assume anything you like, but this isn't Sonoma, CA we're dropping the people off at, you cannot simply dump 1000 people, and then forget how many launches they need ever launch window going forward. There is zero chance they are self-sufficient from the start. What is a reasonable time window for this to be achieved? 10 years? Is that 10 years for just 1000, or for 5,000? It matters.

 

Year 1 launch 25 MCT. (1000 people, plus supplies)

Year 3 launch 45 MCT. (1000 new people, plus supplies for previous 1000)

Year 5 launch 65 MCT. (1000 new people, plus supplies for previous 2000)

Year 7 launch 85 MCT. (1000 new people, plus supplies for previous 3000)

etc. How sustainable is this scenario?

Well, the new people will need to work on Mars to help produce stuff for ohers, so the amountof resupply woulddecline over time.

[KSK]

11 minutes ago, kunok said:

I came here cheerful and I was trying to be constructive and helpful proposing a long term plan based in necessary research. But if we say what are bad in your plan you only put this in your op "Okay, drop all criticisms/pessimism you may have for Mars colonies, or a SpaceX Mars colony, as this is a thought experiment; Here are the questions" not fixing anything at all of your plan. And now instead of cheerful I'm just tired.

For an airtight airlock manufacturing? Actual tech level. You don't make an airtight seal without high tech, same for an space suit.

I'm sure you did intend to be helpful but I think you also missed the point of the thread, which was set up to be a thought experiment. OP was presuming we can get to Mars with enough equipment for survival. The question is - what next? What do we need to survive on Mars in the long term. What do we need to establish a colony? How can we make that colony more self-sustaining? (Accepting that full independence isn't going to happen for a long time.)

Also with respect, a lot of your so-called necessary research doesn't actually tell us anything useful or new.

They will start to develop Bion https://en.wikipedia.org/wiki/Bion-M_No.1 like proves, for sending to free return trajectories when available or little dv to return ones, because if not he launch windows will be very limited, to Mars and Venus. This will evaluate long space travel effects in animals, also can double as a test for an interplanetary re-entry capsule.

Interplanetary reentry capsules we can do. See Stardust, or the Mars Polar Lander. Sure, the MPL crash-landed but as far as we know, it survived reentry from interplanetary speeds just fine. Long term space travel effects in animals - we don't have any shortage of data from the ISS nor data from radiation exposure studies on Earth. Besides, trying to extrapolate from animal studies to effects in humans isn't necessarily going to work very well.

The first ones goes pretty bad (reasonable assumption being the first) but it has data from almost half of the travel to venus (first we star with venus, less Dv requirements, and more frequently available launch windows, so a delay in development isn't that bad), like the animals food consumption rates in free fall and interplanetary radiation levels. Biology basic data.

Interplanetary radiation levels we can get with a robotic probe (assuming we don't have the data already). Why do we need animal food consumption rates in free-fall when we've had humans living in free-fall for months at a time on the ISS?

At the same time as the animals probes, they start developing plants proves, starting a research about plants growing in low gravity, for that mission they start looking at the moon. A little lander lands in the moon, with some short-life plants, they grow erratically but some survives the 14 day day of the moons. They all die in the night (by design), they try to regrowth again in the next moon day but it doesn't work.

We've grown plenty of plants in space. If we can grow them in space with no gravity to provide their normal growth cues, they're probably going to grow just fine on Mars, where there is gravity. Growing them for 14 days on the Moon and letting them die by design (why are we doing that anyway?) isn't going to tell us much. I will concede that growing them for longer on the Moon might tell us something but if we're going to be sending people to Mars anyway, why bother? Just do the experiments on Mars. It's not like we need to be growing food from Day 1 on Mars anyway.

The second animal probe survives the travel to venus but not the re-entry to earth, proving basic life support and food storage technologies for space travel. It also gets valuable data about the animals.

How basic are we talking about here? Again, apart from radiation shielding, we have ample data on basic life support and food storage (seriously?) from the ISS.

A series of landers get more and more valuable data from low g growth in the moon, looks like some plants adapt to the moon, but they are not as healthy. They keep trying new plant types. Some even regrowth after the moon night.

See previous comments.

The third animal probe takes the same destination, this is an experiment looking how different foods affect the long term exposure of radiation or microgravity, if some of them helps to mitigate some of the effects. Maybe it also test some chems for that purpose. The prove re-enters in earth without killing everything in it. The fourth animal probe goes to Mars, testing longer exposure in interplanetary environment, it survives all the travel, even the re-entry but it goes bad for lots of the animals. They get valuable data and start researching improvements of the design.

This might be useful but again I'd be very wary about extrapolating results in animals to useful effects in humans.

The next series of landers in the moon tries to growth plants, and release a laboratory mice (obviously until this moment it had other food source) when they grow enough to eat. The mice survives until the moon night. Results looks promising.

See previous comments.

With regard to your comment about airlock doors - a gasket hardly qualifies as high tech. Manufacturing suitable materials is a bit more high tech but a Mars colony is going to need some kind of chemical industry anyway. There's a lot you can make starting from CO2 and water, including some synthetic rubbers which should make you a nice gasket for your airlock. The real trick is going to be making chemical reactors that are rugged and portable enough to send to Mars.

 

 

 

43 minutes ago, fredinno said:

Yeah, but I thought this is not supposed to be a sci-fi world, this is a forum for SCIENCE.

ROFL. If we threw out all the sci-fi threads in this forum, we'd have virtually nothing left.

 

[Mikki]

"I am no expert."

1. Mars equator, lowest elevation, depends on soil/ rock/ resource prospect.
2. Alloy (BAUXIT), silicon for large scale glass production, and clearly, Dihydrogenmonoxide
3. Underground nuclear powerplant, able to seal itself in case of meltdown.
    Underground habitation under glassroof at surfacelevel. (One surface to maintain, control, seal)
    Underground greenhouses and artificial mini-ecosystems under glassroof at surfacelevel.
    Minimal surface buildings for landingstrips/launchpads (mars weather risks)
4. Depends how well the system performs. 100 years make mars a nice place to live, maybe 200 years.

Edited February 23, 2016 by Mikki

[tater]

34 minutes ago, fredinno said:

Well, the new people will need to work on Mars to help produce stuff for ohers, so the amountof resupply woulddecline over time.

They'd either show up with the capability to produce replacement parts or they'd not have that capability for a very long time. Construction, even farming could be labor intensive. "Mining" on Mars would largely be harvesting the atmosphere, though you could drive water, etc, off regolith as well---that could use a few people. Industrial capability would need to be delivered. 

In the indeterminate future, we could have truly game-changing manufacturing technology as 3D printing matures. It's all the rage now, of course, but I worked with rapid prototyping guys at Sandia Labs, gosh, 20 years ago. The machines are far cheaper now, but the quality is not really much different as far as I can tell (the new laser sintering stuff is substantially different though). Then the manufacturing using isru needs to focus on making printer supplies. What size plant would you need to harvest enough carbon to meet the plastic needs of a growing colony?

 

 

[Spaceception]

1 hour ago, KSK said:

I'm going to add a fifth question to OP's list. What is the minimum level of technology needed to survive on Mars once you get there? 

 

Added, that's a good question.

 

1 hour ago, kunok said:

I came here cheerful and I was trying to be constructive and helpful proposing a long term plan based in necessary research. But if we say what are bad in your plan you only put this in your op "Okay, drop all criticisms/pessimism you may have for Mars colonies, or a SpaceX Mars colony, as this is a thought experiment; Here are the questions" not fixing anything at all of your plan. And now instead of cheerful I'm just tired.

And yet we only can support 9 humans in low orbit with regular supplies even 60 years later. Maybe it's because it's not comparable at all? Human presence it's very hard, we needed a lot of stations and research to get to this level of ours life supports systems, and we will need betters. The moon was based in supplies, not in close life support systems, systems that will be needed for a simple outpost outside earth, and colonization and self-sufficiency is even another level.

Here is the funny part: your plan is a lot less realistic that the Mars one's one and your points are very applicable to your space X based plan, every one. And I know that Mars One is or a scam or an absurdly optimistic plan.

I edited the OP to make it more realistic, and after reading through this forum post, I guess I was to hasty with this.

I was only pointing out that if we put our minds to it, we can achieve big things within a couple of decades or less, as well as pointing out that NASA originally wanted to begin research on a Lunar colony with the Apollo program.

Yeah... again, reading through this post, I guess it is.

[kunok]

It's late so don't expect good English not very clever reasoning

1 hour ago, KSK said:

I'm sure you did intend to be helpful but I think you also missed the point of the thread, which was set up to be a thought experiment. OP was presuming we can get to Mars with enough equipment for survival. The question is - what next? What do we need to survive on Mars in the long term. What do we need to establish a colony? How can we make that colony more self-sustaining? (Accepting that full independence isn't going to happen for a long time.)

He changed the op after what I said, making everything I said weird, and then I replied again like he didn't changed the OP, the last it's my fault.

11 minutes ago, Spaceception said:

I edited the OP to make it more realistic, and after reading through this forum post, I guess I was to hasty with this.

I was only pointing out that if we put our minds to it, we can achieve big things within a couple of decades or less, as well as pointing out that NASA originally wanted to begin research on a Lunar colony with the Apollo program.

Yeah... again, reading through this post, I guess it is.

Sorry if I looked rude or something

1 hour ago, KSK said:

Interplanetary reentry capsules we can do. See Stardust, or the Mars Polar Lander. Sure, the MPL crash-landed but as far as we know, it survived reentry from interplanetary speeds just fine. Long term space travel effects in animals - we don't have any shortage of data from the ISS nor data from radiation exposure studies on Earth. Besides, trying to extrapolate from animal studies to effects in humans isn't necessarily going to work very well.

Well I was very sleepy at that hour so I didn't explain a lot of things.

Stardust had a re-entry g peak of 34g from interplanetary velocities, that's not very survivable, I was thinking about low g re-entries to earth, as far I know there is no data.

ISS is inside of the Earth magnetosphere, we don't have an exact idea of how interplanetary radiation affects organism, it's a very different type of radiation than the ones we are used to, like heavy nuclei ones.

I know extrapolation sometimes doesn't work, but you will send first an human without data?

1 hour ago, KSK said:

Interplanetary radiation levels we can get with a robotic probe (assuming we don't have the data already). Why do we need animal food consumption rates in free-fall when we've had humans living in free-fall for months at a time on the ISS?

The same as above for the radiation. The food thing is wrong, I just didn't know

1 hour ago, KSK said:

How basic are we talking about here? Again, apart from radiation shielding, we have ample data on basic life support and food storage (seriously?) from the ISS.

Unattended and miniaturised close cycle basic support. We have good data of how things like heavy nuclei radiation affects food? (I really don't know)

1 hour ago, KSK said:

We've grown plenty of plants in space. If we can grow them in space with no gravity to provide their normal growth cues, they're probably going to grow just fine on Mars, where there is gravity. Growing them for 14 days on the Moon and letting them die by design (why are we doing that anyway?) isn't going to tell us much. I will concede that growing them for longer on the Moon might tell us something but if we're going to be sending people to Mars anyway, why bother? Just do the experiments on Mars. It's not like we need to be growing food from Day 1 on Mars anyway.

Data from low g growing. It's not the same microgravity than low gravity, maybe it works fine maybe not that fine. That's why is the experiment, you want optimum plants for the outpost so you can minimise the size of the "farm". And it for the moon because the moon it's close, easy and we have abundant launch windows.

Again my point of view is test tech and when it works send humans not in reverse. And it's a lot cheaper to send a probe with the experiment than sending humans to experiment.

1 hour ago, KSK said:

With regard to your comment about airlock doors - a gasket hardly qualifies as high tech. Manufacturing suitable materials is a bit more high tech but a Mars colony is going to need some kind of chemical industry anyway. There's a lot you can make starting from CO2 and water, including some synthetic rubbers which should make you a nice gasket for your airlock. The real trick is going to be making chemical reactors that are rugged and portable enough to send to Mars.

The trick about that kind of rubber seals isn't only the materials, is also the molds, and you need the high precision for the mold. Of course you can import from the earth but there it goes the self-sufficiency. And an airtight is more difficult than the gasket. I was thinking more about the pressure differential, the airlock mechanism. I wouldn't want an ghetto airlock. My solution? The airlocks are imported, for a chair you don't need that kind of tech, but that's not selfsufficency.

[DBowman]

On 2/23/2016 at 1:37 PM, tater said:

I was saying that in their critique of MO, the MIT guys provided useful benchmarks in units of 4 people and D2 landings on the martian surface. Using their data, which seems reasonable, their logistical train for 4 people was about 4 D2 landings (2 mt useful payload each).

I read the MIT paper and thought it had two significant errors in it around the 'contingency spare parts' (things that might or might not break), their logic seemed solid for consumables.

My logic is as follows; name the 4 man crew + Habs + life support chunks C.1, C.2, etc. To be 99% sure you can fix what breaks for C1 you have to take S spares. The MIT paper said C.2 had to bring 2*S spares (S for C.2 and another S for C.1), C.3 had to bring 3*S spares. This logic works for consumables but not for contingency items:

1. When you have 2 Crews and each has S spares then you are 99.99% sure to fix what breaks. The crews are co-located and can share a common spares pool. The chance of not being able to fix things is 0.01 for C.1 and 0.01 for C.2, one percent of one percent. So MIT increased the safety factor by 100 every window - mass does not need to be sent. I feel like 2 Crews only need 2^1/2*S spares, 3 Crews only 3^1/2*S, etc. but I haven't proven it to myself. 
2. When C.2 launches you know what already broke for C.1 and what didn't (yet), so C.2 only has to take enough spares to bring the total up to 2^1/2*S - if they were lucky and nothing actually broke for C.1 then C.2 only needs to take 0.41*S not the 2*S MIT was computing with.

I don't know how far the contingency spares tip the balance, designing for minimal consumables and ISRU is going to be key.

[kerbiloid]

Imho, the calculation of a self-sustained Mars colony would be preceded by a calculation of a self-sustained Antarctic colony.
Then just add what you need else for Mars.

[tater]

Yeah, there could certainly be some economies of scale with people sharing habitation. On the other hand, more people could create more wear and tear... I honesty don't know.

The other issue is that a failure without recourse results in death for everyone sharing life support. A 1% chance of killing 4 people is different to consider than a 1% chance of 100 or 1000 deaths.

[Rakaydos]

Theres a large gap between a mission running on consumables, a mission relying on imported durable goods (imported manufacturing machines) and self sufficency.

[KSK]

15 hours ago, kunok said:

It's late so don't expect good English not very clever reasoning

He changed the op after what I said, making everything I said weird, and then I replied again like he didn't changed the OP, the last it's my fault.

Sorry if I looked rude or something

Well I was very sleepy at that hour so I didn't explain a lot of things.

Stardust had a re-entry g peak of 34g from interplanetary velocities, that's not very survivable, I was thinking about low g re-entries to earth, as far I know there is no data.

ISS is inside of the Earth magnetosphere, we don't have an exact idea of how interplanetary radiation affects organism, it's a very different type of radiation than the ones we are used to, like heavy nuclei ones.

I know extrapolation sometimes doesn't work, but you will send first an human without data?

The same as above for the radiation. The food thing is wrong, I just didn't know

Unattended and miniaturised close cycle basic support. We have good data of how things like heavy nuclei radiation affects food? (I really don't know)

Data from low g growing. It's not the same microgravity than low gravity, maybe it works fine maybe not that fine. That's why is the experiment, you want optimum plants for the outpost so you can minimise the size of the "farm". And it for the moon because the moon it's close, easy and we have abundant launch windows.

Again my point of view is test tech and when it works send humans not in reverse. And it's a lot cheaper to send a probe with the experiment than sending humans to experiment.

The trick about that kind of rubber seals isn't only the materials, is also the molds, and you need the high precision for the mold. Of course you can import from the earth but there it goes the self-sufficiency. And an airtight is more difficult than the gasket. I was thinking more about the pressure differential, the airlock mechanism. I wouldn't want an ghetto airlock. My solution? The airlocks are imported, for a chair you don't need that kind of tech, but that's not selfsufficency.

Well, I'd have a tapered hatch, such that the higher pressure inside your hab forces it into its frame. I'd also go with a tubular gasket - just extrude your synthetic rubber through a circular die and melt the ends together to give you a continuous loop. Stick loop to hatch frame, done.

But your point still stands - manufacturing stuff off-world is going to be difficult and everything that you need to import from Earth, makes you that bit less self-sufficient. Like I said - I think a truly self-sufficient colony is a very long way off, even in the context of OP's thought experiment.

You're absolutely right about Stardust. On the other hand, I would think that any crewed mission to Mars will probably involve going into orbit around Mars and then descending to the surface from orbit, rather than re-entry from interplanetary speeds. The g-loading would be more survivable that way. Apparently the Apollo capsules would be peaking at around 7g on re-entry, so we do have some data on low g reentry.

For radiation studies, I would use an unmanned probe. Basically a collection of boxes with radiation detectors in, wrapped in whatever shielding you want to try. Measure the radiation dose inside your box and see if it's low enough that the risk to crewed flights is acceptable. I'm honestly not sure how much use any biological models would be.

For growing crops, to be honest, I'd go straight to Mars and make that the first priority and go/no-go point for the colony. Assume that your colony is going to start off entirely supplied from Earth. Their first task is to grow food. If they can't then you bring them home (because the colony is never going to be viable), or just commit to regular supply runs from Earth. If you really wanted to do some studies ahead of time, go for an Elon's Greenhouse approach and do those studies on Mars.

[tater]

I'd think the first experiment would be to buy a couple large Bigelow habs, then spin them up to 0.38g and see how people (and animals) do long-term. That can at least establish if there are acute issues associated with some g level below 1, and above 0 (a regime for which we have zero data). If martian gravity won't cut it long term, there is no reason to bother with any of the rest of it at all.

[Spaceception]

2 hours ago, tater said:

I'd think the first experiment would be to buy a couple large Bigelow habs, then spin them up to 0.38g and see how people (and animals) do long-term. That can at least establish if there are acute issues associated with some g level below 1, and above 0 (a regime for which we have zero data). If martian gravity won't cut it long term, there is no reason to bother with any of the rest of it at all.

They'd need to be really big to counter-act the Coriolis effect.

[tater]

24 minutes ago, Spaceception said:

They'd need to be really big to counter-act the Coriolis effect.

The abs themselves need only be as big as you'd like them to be for living for that period (or just one, with perhaps the return craft and service module as counterweight), then a long cable. have them rotate about a 100m CM, keeping RPMs down.

A 100m tether (floor to center point, so the cable is slightly shorter) means 1.84 rpm. If they used 2 Bigelow habs, they could have a ~43m tether from the center point, place one, then a second at the full 100m length and you could experiment with lunar and martian at the same time.

Edited February 24, 2016 by tater

[kunok]

5 hours ago, KSK said:

Well, I'd have a tapered hatch, such that the higher pressure inside your hab forces it into its frame. I'd also go with a tubular gasket - just extrude your synthetic rubber through a circular die and melt the ends together to give you a continuous loop. Stick loop to hatch frame, done.

But your point still stands - manufacturing stuff off-world is going to be difficult and everything that you need to import from Earth, makes you that bit less self-sufficient. Like I said - I think a truly self-sufficient colony is a very long way off, even in the context of OP's thought experiment.

I will use an internal room as the airlock and just an airtight door to the outside and other to the inside, I don't see the reason of using a tubular gasket (Note I part from the assumption than the base will be underground for radiation shielding), maybe I'm not understanding what do you mean.

Now that I think about rubber and other polymeric materials doesn't stand very well the temperatures of Mars, rubbers tends to harden in low temp, no?.

Somewhat returning to topic:

I think the first manufacturing processes will be based in polymers derived from plants, is easy when you know what you do, you can do with little equipment. Ethylene is basically dehydrated alcohol, and a plant hormone that you need to filter in your farm air, polyethylene is the most used plastic. And I'm mostly an metal manufacturing engineer, so no job for me . Seriously, the metallurgy installations are very huge, very dependent from the chemical industries (and the steel industries from the carbon) and very power hungry, and if you want to use the metals you also need a lot of other heavy equipment for machining, forging etc. I don't think we can make them very little, I think the minimum size and mass to do an acceptably alloy will still be very huge. The view of an medieval fellow using iron ore and carbon to make steel and then forging, that I think is what most people have in mind when they talk about siderurgy, isn't a good comparison at all, you don't have neither carbon neither oxygen in Mars and you need to produce a lot more advanced equipment...

5 hours ago, KSK said:

You're absolutely right about Stardust. On the other hand, I would think that any crewed mission to Mars will probably involve going into orbit around Mars and then descending to the surface from orbit, rather than re-entry from interplanetary speeds. The g-loading would be more survivable that way. Apparently the Apollo capsules would be peaking at around 7g on re-entry, so we do have some data on low g reentry.

Oh, I was thinking about the return to the earth from the first trips, I think the idea of colonising from the first travel is very silly. In Mars you need to use rockets for landing so you probably will made a full controlled descend. But I was picturing an aero-capture to low orbit in earth, and then landing.

5 hours ago, KSK said:

For radiation studies, I would use an unmanned probe. Basically a collection of boxes with radiation detectors in, wrapped in whatever shielding you want to try. Measure the radiation dose inside your box and see if it's low enough that the risk to crewed flights is acceptable. I'm honestly not sure how much use any biological models would be.

But we don't have data about cosmic rays effects in live begins, we can measure cosmic rays or solar particles, but we need that data to translate them to cancer probability or whatever. I don't have a better source in English: https://en.wikipedia.org/wiki/Health_threat_from_cosmic_rays#Human_health_effects

5 hours ago, KSK said:

For growing crops, to be honest, I'd go straight to Mars and make that the first priority and go/no-go point for the colony. Assume that your colony is going to start off entirely supplied from Earth. Their first task is to grow food. If they can't then you bring them home (because the colony is never going to be viable), or just commit to regular supply runs from Earth. If you really wanted to do some studies ahead of time, go for an Elon's Greenhouse approach and do those studies on Mars.

I'll bet that with the price of only one human trip mission to Mars you can pay a full probe based biologic studies program of the moon, venus and mars.