Let's Design a Settlement for Mars!

[spacester]

Another quickie - it's nice to see this thread still has momentum despite my neglect . . . <br /><br />By definition (mine), for purposes of this thread, a Settlement does not produce babies but a Colony does. Certainly a Settlement needs to grow, but that growth is by adding adult Earthlings.<br /><br />My personal hunch is that gestation in less than 1 gee is going to be very very difficult. Given the lack of science on the question it seems totally irresponsible to me to plan on making babies on Mars until such time as we are well established there.<br /><br />We can shed some light on the subject with experiments in spin-g habitats, but if it proves problematical, we won't know if the gravity gradient or coreolis effects are contributing factors. OTOH, if it works in spin-g, it should be fine on Mars. <br /><br />Even so, while the purpose of the Settlement is to determine the feasibility of a Colony, IMO the Settlement should be well along before anybody gets preggers. I would worry that taking care of the pregnancy could somehow endanger the rest of the Settlement. <div class="Discussion_UserSignature"> </div>

 

[arobie]

Dan_Casale,<br /><br />Your food and water comsumption and recycling plan is very in depth and looks to be very efficient. You've designed a complete ecosystem!<br /><br />I think you should start a new thread to work out 'to do's' on the "To Do list".<br /><br />Something as complex as this deserves it's own thread, and there might be some expertise out there that could help us and hasn't read these threads.<br /><br />Sorry, not much of an educated response like I promised, but I don't know enough about the subject to sound halfway intelligent yet. That of course assumes that I sound halfway intelligent most of the time...atleast I hope I do. <img src="/images/icons/crazy.gif" /><br /><br />Well more importantly, I hope there are others on these forums who might be able to help with your ecosystematic life support system.

 

[spacester]

Just a quick note again, I'm working on a Summary, thanks to Arobie who has sent me a first draft. I'll be posting that later today.<br /><br />But I felt the need to extend kudos to Dan_Casale, something I've neglected. That's great stuff, and I salute you, sir. I'm with Arobie - we should start a separate thread on the technology of a closed ecosystem in reduced gravity. If I don't get to it today, you should of course feel free to do so yourself.<br /><br />"ecosystematic" - what a great word! <div class="Discussion_UserSignature"> </div>

 

[grooble]

Life support discussion: <br /><br />http://www.newmars.com/cgi-bin/ikonboard/ikonboard.cgi?s=3eff2c37d4a0a64c284f4ec0911c1ab0;act=SF;f=8<br /><br />

 

[arobie]

Scottb50,<br /><br />Thanks for those links. Sorry for the late reply.<br /><br />I'm going to take a look at them.<br /><br />spacester,<br /><br />Thinking back on the Cargo Lander, I've come to the conclusion that we should leave the CL at Mars. <br /><br />On it's trip to Mars, we can send it fully loaded...maybe with the first generation ISRU factory or power plant. Then after that, we send the cargo packed into a module (or modules) that the CL will dock with and transport to the surface. We won't have to transport the engines or tanks that go with the CL to and from Mars every trip, only a module container that holds cargo.<br /><br />BTW: I had not known that "ecosystematic" was actually a word. <img src="/images/icons/laugh.gif" /><br /><br />grooble,<br /><br />Cool forums. Thanks.<br /><br />You asked earlier about having spin gee on the surface. I don't think we will have that, but we could have the necessary spin gee in orbit if there is no other way for pregnancy in the future when the settlement becomes a colony. <br /><br />Speaking of the spin-gee, how much of one gee will we have in orbit? Will it be at 1/3 gee like Mars or will it be higher?

 

[spacester]

Yeah, Arobie, I was thinking the same thing about the Cargo Lander. Kind of obvious in hindsight actually. We want to re-use everything as much as possible, why would we send the lander all the way back to Earth? Simply use it at Mars as long as possible. Maybe we send a second one at some point for redundancy.<br /><br />I was going to tease you about 'ecosystematic' but thought I'd run it past dictionary.com first and was surprised as well. <img src="/images/icons/laugh.gif" /><br /><br />We'll know a lot more about exactly how to configure Mars orbital spin-g after we get some experience in LEO. One reason I want to use the habitat - truss - hub - truss - habitat design concept is that additional trusses could be "spliced in" to create a longer spin radius, so you could get 1.0 g with the same RPM and thus the same Coreolis effects. <div class="Discussion_UserSignature"> </div>

 

[dan_casale]

Spacester:<br />Thanks, I'm glad you like the work. However, I disagree about starting a separate thread. I think that if we start too many threads we will loose track of things. I am also serious about making presentations on this plan at space conferences. At this rate we could have something presentable in about one year.<br /><br />Grooble: Thanks for the link. I will review and incorporate what I can into the green house stuff. I am also going to post it on some other forums to get additional feed back. I'm sure there are major wholes in it.

 

[arobie]

We've outlined the Manned Mars Transfer Ship as having a:<br /><br />First Stage Interplanetary Booster<br /><br />Second Stage Habitat Setup<br />&<br />Third Stage Storage Module and possibly Mars vehicle<br /><br />The habitat setup is two habitats on the ends of trusses connected to a hub.<br /><br />Could we engineer storage for supplies for the journey into the hub?

 

[ldyaidan]

They are holding that contest right now for extracting oxygen etc from lunar regolith. If this proves out, we should see about using that technology, and sending robotic equipment to start extracting ISRU prior to the manned mission. <br /><br />Rae

 

[arobie]

To er... answer my own question, <img src="/images/icons/blush.gif" /><br /><br />I quess not, although we could put computers to connect the habitats down there at the hub.

 

[arobie]

<b>Design Thread Checklist</b><br /><br />+ Determine initial crew size (<i>Check</i>)<br /><br />+ Determine Power Source. (<i>Check</i>)<br /><br />+ Determine Propellant. (<i>Check</i>)<br /><br />+ Design Ecosystematic Life Support for Settlement. ***<br /><br />+ Design Life Support for Transfer Ships and Martian Vehicles.<br /><br />+ Design the Transfer Vehicle. (<i>Check</i>)<br /><br />+ Work out Phobos Operations.<br /><br />+ Brainstorm Recreational Activities.<br /><br />+ Roughly Outline time table for transporting equipment and settling Mars. (<i>Check</i>)<br /><br />+ Revise that Outline<br /><br />+ Determine Power Needs.<br /><br />~Communications<br /><br />~Transportation<br /><br />~Habitats<br /><br />~Factories<br /><br />~Ecosystematic Life Support<br /><br />~Avionics and Computers<br /><br />+ Determine approximate mass needed to be transported to Mars.<br /><br />~Food, water, and atmosphere mass. (<i>Check</i>)<br /><br />~Interplanetary Booster Dry Mass.<br /><br />~Habitat, Trusses, and Hub Mass.<br /><br />~ISRU Factories Mass.<br /><br />~Power Plant Mass.<br /><br />~Martian Vehicles Mass.<br /><br />~Ecosystematic Life Support Mass<br /><br />+ Calculate Propellant Mass.<br /><br />------------------------------------------------<br /><br />***Dan, Excellent job. I'm following you thread over here. I'm glad they are able to help.

 

[spacester]

<font color="yellow">Could we engineer storage for supplies for the journey into the hub? </font><br /><br />Cool, we can get back to the ship design a bit, other things are proceeding apace today. <img src="/images/icons/laugh.gif" /><br /><br />The conceptual design for the transit craft is only that - just the major building blocks in relationship to each other. No proportions are known - how squat or tall the habitat, the size of the hub in relationship to everything else, if the Interplanetary booster is much bigger than the rest of the hub, lots of other stuff.<br /><br />We have a spin radius based on our best guess at tolerable Coreolis (cross-coupling of angular momentum) levels, but must remember that the gravity gradient problem is not eliminated, just reduced to tolerable levels as well. The gravity gradient thing is probably easily handled by simply going from floor to floor where there would be a slightly noticeable but tolerable change in the spin-g acceleration magnitude.<br /><br />The gravity gradient thing might turn out to be a lot of fun for all we know.<br /><br />As far as the spin axis is concerned, the hub is conceptually two metal cans and an Interplanetary Booster. <br /><br />The hub itself is one of the metal cans, it attaches directly to the trusses. It might be pressurized along with man-passage in the truss, but its primary function is structural. It not only holds onto the habitats and accepts the load applied by the IB (Interplanetary Booster), it provides bracing (cables) to the trusses.<br /><br />The other metal can is the storage module, attached to the opposite side of the hub as the IB. We're taking a lot of supplies with us, but a lot of the water will be used as shielding around the habitats, so I don't have a handle on the relative size of the storage module and the hub.<br /><br />The thing is, the geometry allows for the thing to come together as we figure out the mass and volume allocations for the systems. So over the next sev <div class="Discussion_UserSignature"> </div>

 

[arobie]

It has been laid out in great detail how we are to provide food and recycle air and water for the crew at the settlement. We are of course going with a biological system because of it's efficiency. Such a system is very massive which is ok as long if it just sits on Mars, however, such a system would not be advantageous on the ships.<br /><br />Like Scottb50 pointed out a month ago, it is not feasible to lug around such a massive life support system every trip. So for the transfer ships, I recommend using a dual system, using both biological and mechanical means to support life. But how much biological, and how much mechanical? That is what I would like to address now.<br /><br />We will use aquaponics to recycle CO2 back into O2 and possibly also povide some food. Could we eat some of the fish from the aquaponics? How about plants? In fact, what plants and fish are used in aquaponics? (spacester, these questions are directed at you. I have not forgotten about you and aquaponics. <img src="/images/icons/smile.gif" />)<br /><br />Will we use both aquaponics and hydroponics, or will we only need aquaponics? <br /><br />The plants might be able to recycle all of our oxygen, but that depends on how many we bring. If they cannot, we will have to also bring mechanical means, and if the can, we should still bring mechanical means as backup just not as much of it.<br /><br />Lets see, what else do we need to do to keep the atmosphere breathable...<br /><br />We need to pull water vapor and small air-born particles (dust) out of the air.<br /><br />The water vapor is easy, filter the air past anything below the 0 C and the water will fall out of the air for us. Thank you Scott for that. <img src="/images/icons/smile.gif" /><br /><br />As for the small air-born particles, is that as simple as running the air through a simple filter to pull

 

[arobie]

Back to ship design!<br /><br />Ok, so mass allocations...<br /><br />So far, we know the basic resources needed for the crew.<br /><br />Water:<br /><br />Up until now, we have been planning to take 960 days worth of water with us on the trip. We don't need to do that. Water and other supplies should already be at Mars prior to the crew arriving. In fact, by the time the first crew arrives, we should already have 960 days worth of water at Mars; 600 days worth on the surface, and 360 days worth in orbit. Assuming the longest travel time, 200 of those days worth in orbit would be for the return trip. The other 160 are in orbit for the refuge, and can be taken down to the surface if needed. <br /><br />(The 200 days worth of water in orbit for the return trip is just a precaution. My standard has been assuming that one day of water supports 28 people for that day. We hopefully will not need enough water to support 28 people for 200 days for the Earth-Return trip because not everyone is returning home. It is up there just incase everybody is forced to return home by some unfortunate event.) <br /><br />Therefore, since we will have plenty of water at Mars already, we will only need to bring 200 days worth of water on the transfer ship for the crew. That is 60,816 kilograms of water. <br /><br />Now that is what we need to bring, but we should of course bring more than that to build up our water stores at Mars. I recommend that we bring 300 days worth of water with every crew transfer ship: 91,056 kg of water.<br /><br />Is it possible for Dan's ecosystematic life support system to nearly approach 100% water efficiency? Dan's system will recycle all water, and unless our water is disappearing we will not lose any. Could it reach 100% efficiency? Dan?<br /><br />If we get an extremely efficient system, then we will not need to keep bringing in tons, figuratively, of water. We will mainly need to bring in enough to support any increase in the settlement's population.<br /><br />Oxygen:<br />

 

[spacester]

The 960 days supply came out of covering the contingency where you cannot get captured in Mars orbit, you have to go back to Earth first.<br /><br />Is our settlement going to be robust enough to eliminate that requirement? A big question. <div class="Discussion_UserSignature"> </div>

 

[grooble]

I was wondering what it would cost to get 180,000kg on mars, thats the 600 days worth of water.<br /><br />Falcon 5 can get 1200kg to escape velocity, that is what is needed right?<br /><br />say 300kg for capsule weight / landing stuff, leaves 900kg of water = 200 Falcon 5 launches for the 600 days worth of water.<br /><br />$17m a launch, that would = $34b just for the water! I must be way off right? What did i do wrong?<br /><br />Edit: I think its $3.4 billion actually. Still, my new idea brings that down by a factor of 5 to around 650 million.

 

[arobie]

spacester,<br /><br />Damn! I had just typed a long post and my computer ate it up!<br /><br />*Sigh*<br /><br />Oh well to start again...<br /><br />If the crew can't get captured into Mars orbit, aren't they screwed anyways?<br /><br />Or did you mean if the crew cannot make it to the surface for any reason?<br /><br />If the latter, then we can just adjust the proportion of the original supplies that remain in orbit brought in the previous mission. We should have 960 days of water at Mars prior to the crew arriving. The crew is bringing 300 days of water. but by the time that the crew arrives at Mars, only 100 days will be left. We will have left 660 days of water in orbit and have brought 300 days to the surface in those precursor missions. This way the crew will have access to 760 days of water if they are stuck in orbit until the next return window. <br /><br />If they can make it to the surface, then they just bring down what water they need to the surface. They would bring down 560 days worth of water to the surface and leave 200 days up in orbit. The 200 days of water are in orbit for the return trip, and they are only a precaution, just incase the entire settlement needs to return home for some unfortunate reason. If the entire crew does not need to return home, then the returning crew takes what water they need, and the rest is brought down to the surface for the remaining crew.<br /><br />Leaving that much water (660 days worth) up in orbit is of course only for the first crew of 28, maybe first two crew cycles. For later crews, it will be much less likely that anything could go so wrong that they are unable to reach Mars' surface or are all forced to leave. With people already at Mars or having been at Mars for a while, anything malfunctioning can easily be fixed and any bugs in the settlement can be worked out. <br /><br />We must not forget that later crews will not be a full 28 people, so bringing 960 days of water every trip or having the capability to do so is not n

 

[spacester]

Nice analysis, Arobie.<br /><br />Yeah, I was worried about the case where your rockets don't fire enough to get captured at all, but you somehow can get on an Earth-return trajectory. Can we cover this contigency by the logistics of our food and water rations? Does our abundance mentality allow us to automatically have this contingency covered? Without studying it,I'm guessing your analysis shows it works for the water. But what about the food? Do we put extra food on the transfer ship in case they're space-bound for 1000 days? I dunno.<br /><br />The deltaV at arrival is low in my strategy, almost low enough for aerobraking alone. But we don't want to go that low in the well with the IB, so you get captured in HEMO using rocket power alone. Then the much less massive spin-g craft transfers down to LMO to access the surface. The point being that we'll have spare prop for multiple engines of high reliability, only being asked to provide much less impulse than when you fired them 200 days earler. <br /><br />Given that, do we even worry much at this point about the continuous abort mode I bring up?<br /><br />Oh, and we haven't decided on the size of later crews after the first 28. We know how to build a 28-person transfer ship, so . . . maybe we try to add 28 each time. <br /><br />Oh part two, the water goes to grey water, you process it back to purity while lingering in orbit. One possible strategy anyway. <div class="Discussion_UserSignature"> </div>

 

[grooble]

Guys keep an eye on the MARSIS program. If it finds water underground you might not need as much sent before the settlers land. You'll need to send the equipment to extract it.

 

[dan_casale]

Arobie:<br /> />>Is it possible for Dan's ecosystematic life support system to nearly approach 100% water efficiency? Dan's system will recycle all water, and unless our water is disappearing we will not lose any. Could it reach 100% efficiency? Dan? <<<br /><br />Let's call it 95%. Over at www.newmars.com a good point was brought up about the unknowns of the Martian regolith. One process might be to "wash" the regolith to remove undesireable items. <br /><br />I think this leads us to two topics. A Martian water supply, and (banned topic) the Martian cycler. The amount of water used by the last mission would be brought up the cycler by the next crew and the wastes from that mission would be dropped off at Mars.<br /><br />A water supply on Mars is critical to the survival of the settlement and any long term plans for Mars.<br /><br />The problem with the CELSS system is it covers a lot of area and needs a lot of energy. I am thinking that the food/O2 side of the process will be about 4 acres. The marsh/meadow are another 4 acres, and the pond area about 2 acres. Now if sunlight is 100w per sq.ft. and an acre is 43,560 sq.ft and we want to provide lighting for 10 acres, we need (100 * 10 * 43,560 = 43,560,000watts = /> 43.560 MWp * 24 hr = 1,045.440 MWh's/day. (*wow* it will be a full time job just replacing light bulbs.) <br /><br />It will require about 1,010,000 - 187watt solar panels for a cost of about $808 million USD. They would mass about 18,685,000 Kg (18.5 Kg ea.). It might be cheaper to purchase a company, produce the panels you need to Martian specs, then sell the company. In truth, you would need a little more than twice that many, and enough batteries to store 1/2 the output for the night time. The good news is that if manufactured to Martian specs, they would be much lighter as the highest known winds have the force of about 10-15 MPh Earth winds. Most panels are made to withstand 80

 

[dan_casale]

The level of radiation at the martian surface.<br />Here are some figures, can anyone tell me what the risk level is? <br /><br />http://marie.jsc.nasa.gov/Documents/PS-Nara-Paper.pdf

 

[arobie]

Dan,<br /><br /><img src="/images/icons/laugh.gif" /> <img src="/images/icons/smile.gif" /> <img src="/images/icons/laugh.gif" /><br /><br />Very Cool!<br /><br />Some time ago, I asked you in one of my posts if we would need the capability to send 500 tonnes to Mars with every ship. After your latest posts, I'm beginning to think that we may need more capability!<br /><br />20,000 tonnes, wow!<br /><br />That will definitely set the settlement off on the right foot toward becoming self sufficient.<br /><br />Have you thought about light emitting diodes (LEDs) for lighting?<br /><br />They are more efficient, use much less electricity, and last longer than incandescent light bulbs.

 

[dan_casale]

Yes, LED's would be great. But to cover 10 acres would be WAY too expensive. Not incandescent, florescent. incandescent produces too much heat per watt, and not enough light per watt. I think it might be easier to manufacture florescent tubes than incandescent bulbs on Mars. However, I'm not sure what gasses are in a florescent tube.

 

[arobie]

To manufacture fluorescent tubes you need mercury, an inert gas (usually argon), and phosphor for a powder phosphor coating on the inside of the tube.<br /><br />How Fluorescent Lamps Work from HowStuffWorks.com

 

[dan_casale]

Now that the primary food/water/air/waste production/recycling system is proposed, what about the backup systems. I am going to go with the concept that nothing in the primary can be used by the secondary.<br /><br />Food production:<br />Because all food production is biological, the only acceptable backup is to ship food from Earth (or moon) supplies. It is likely that the two year window will have to be ignored and non-standard trajectories will have to be used. <br /><br />A long term food storage method will have to be devised. What about storing the food in LH2? How long does food keep at -300 C? Would this require a 760 (960 - 200 days to get to Mars) day minimum food storage requirement? <br /><br /><br />Water recycling:<br />Can water be made pure enough for drinking just by evaporation? It seems like the lower atmospheric pressure of Mars would be a big advantage for this type of system. Will Methane, ammonia, and other biological impurities be an out gassing problem, or multiple processes be required?<br /><br />Can a filtering system be an acceptable long term solution?<br /><br /><br />Air recycling:<br />Removal of CO2<br />Removal of methane<br />Removal of other gases<br />Removal of odors<br /><br />I'm guessing this would be like the ISS system, but expanded to match the settlement size.<br /><br /><br />Waste recycling:<br />We could dig a hole and bury it on Mars or we could have one of these (my vote).<br />http://www.changingworldtech.com/<br />I wonder if the water output by this process could be used for drinking water? <br />