Let's Design a Settlement for Mars!

dan_casale · Mar 31, 2005

This table is for 1 - 187watt Kyocera panel. (990mm x 1425mm, 15% efficiency, 18.5Kg earth weight) temp . voltage . amps . . watts . . .amps . .watts . . . . . . Earth . . Earth . . . . . . . . . Mars . . Mars 25 . . 26.10 . 7.1700 . 187.1370 . . 3.0000 . 78.3000 Earth surface 15 . . 27.33 . 7.1382 . 195.0870 . . 2.9682 . 81.1209 5 . . . 28.56 . 7.1064 . 202.9588 . . 2.9364 . 83.8636 -5. . . 29.79 . 7.0746 . 210.7523 . . 2.9046 . 86.5280 -15 . . 31.02 . 7.0428 . 218.4677 . . 2.8728 . 89.1143 -25 . . 32.25 . 7.0110 . 226.1048 . . 2.8410 . 91.6223 -35 . . 33.48 . 6.9792 . 233.6636 . . 2.8092 . 94.0520 -45 . . 34.71 . 6.9474 . 241.1443 . . 2.7774 . 96.4036 -55 . . 35.94 . 6.9156 . 248.5467 . . 2.7456 . 98.6769 Mars surface -65 . . 37.17 . 6.8838 . 255.8708 . . 2.7138 . 100.8719 -75 . . 38.40 . 6.8520 . 263.1168 . . 2.6820 . 102.9888 -85 . . 39.63 . 6.8202 . 270.2845 . . 2.6502 . 105.0274 -95 . . 40.86 . 6.7884 . 277.3740 . . 2.6184 . 106.9878 -105 . .42.09 . 6.7566 . 284.3853 . . 2.5866 . 108.8700 Earth/Mars Orbit -115 . .43.32 . 6.7248 . 291.3183 . . 2.5548 . 110.6739 -125 . .44.55 . 6.6930 . 298.1732 . . 2.5230 . 112.3997 -135 . .45.78 . 6.6612 . 304.9497 . . 2.4912 . 114.0471 -145 . .47.01 . 6.6294 . 311.6481 . . 2.4594 . 115.6164 -155 . .48.24 . 6.5976 . 318.2682 . . 2.4276 . 117.1074 -165 . .49.47 . 6.5658 . 324.8101 . . 2.3958 . 118.5202 -175 . .50.70 . 6.5340 . 331.2738 . . 2.3640 . 119.8548 -185 . .51.93 . 6.5022 . 337.6592 . . 2.3322 . 121.1111 -195 . .53.16 . 6.4704 . 343.9665 . . 2.3004 . 122.2893 -205 . .54.39 . 6.4386 . 350.1955 . . 2.2686 . 123.3892 -215 . .55.62 . 6.4068 . 356.3462 . . 2.2368 . 124.4108 Inroute to Mars As you can see the voltage varies greatly with temperature. Amperage varies with the intensity of light. Temperatures for different places ar

scottb50 · Apr 1, 2005

NiMih batteries are used on satellites, so they might be the best option for electrical storage. NiMih batteries can be cycled about 10,000 times. A better storage idea might be Super Capacitors, which can be cycled 100,000 times..... Or water, it can be cycled indefinitly. Use Solar to break-down water as it is needed. Storage of low pressure Hydrogen is not a great problem, the Germans did a pretty good job when they couldn't get Helium, and not that much would have to be stored anyway for normal use. Backup high pressure storage would be very good though, for emergencies. Keeping the majority of it as water only makes sense. Again multiple units. Every engine or fuel cell has access to at least two propellant sources and multiple access as more Modules are added. Every Manned Module has three electrical and life-support sources each with its own power source. For the most part all of the water used would be recycled continuously. A fairly small amount of water would be required for electrical and life-support, most taken would be used for propulsion enroute and at Mars or the Moon. The same system could run a station on Mars the Moon or a suburban house for that matter. That's why independent Modules are the key. Each manned Module having three independent hydrolizer/fuel cell systems. As the number of Modules increases redundancy increases. As the demand in a specific Module increases more power units could be installed. Lets say a transit ship to the Moon or Mars uses four core Modules for crew and passengers, another four for supplies and at least another four or six for water, until Extraterrestial sources are found and exploited. and hopefully one or two to grow the base. Thats 12 independant electrical systems, figuring one hydrolizer/fuel cell in a cargo Module the redundancy increases to 16. Having any Module capable of adding systems in a plug-and-play manner allows concentration of power so <div class="Discussion_UserSignature"> </div>

grooble · Apr 1, 2005

Yeah, PC style!

dan_casale · Apr 1, 2005

>>Or water, it can be cycled indefinitly. << But the hydrolizer and the fuel cell both require maintenance. Fuel cells have a very short life span ~1 year, that is why they haven't been used in cars yet. NiMih batteries have very little maintenance, check/replace and recycle. Super Capacitors have almost no maintenance, dust them off. />>That's why independent Modules are the key.<< I agree independent/redundent/diverse systems are the key to success.

arobie · Apr 6, 2005

To all, I don't know much about the lastest area of discussion, so I have left it to you qualified enough to discuss. I just sat back, kept up and read the conversation, and learned what I could from it. Now it seems that the discussion has died down. So from these last few pages, what conclusions can be drawn? Is there anything that has been decided? So concludes my bump post.

scottb50 · Apr 7, 2005

That the only realistic means of beginning a human presence in Space is using water. It offers the safest, cheapest, lightest and easiest means of exploring the Solar System. No new science or technology advances are needed to do it, we could start tomorrow. Life cycles of fuel cells/hydrolizers will undoubtedly improve well before initial launches, and if not, ample parts could be made available for overhauls enroute. I would thing alternating them between fuel cell and hydrolizer would help. Compared to the complexity and weight, of carrying hydrocarbon based fuels, as well as the complexity of different engine types for different uses, using water would be a whole lot simpler, easier and do-able. First stage: four SSME's, two extended Shuttle SRM's and four turbofan engines. Releases the second stage at 80 miles and mach 20, then returns for the next flight. Second stage: two RL-10 derivitive engines and propellant tanks. Payloads, attached to the tanks are delivered to a LEO Station, removed and distributed. Second stages are used as Tugs and for vehicle propulsion and surface landers as needed. Payloads are distributed to different orbits by Tugs and destinations by Vehicles. Second stage tanks can also be converted and used indefinitely, in Space, for any number of purposes. Engines are sent back as cargo for overhaul and re-use. Sending water to Space is a whole lot easier than sending any other known source of power. How are you going to keep LOX LOX for four years, even in Space? The volume of CH4 needed would be far greater than that needed by water and you would still need LOX, the heaviest part of the equation, actually. Basically it boils down to Hydrogen and Oxygen, at the end of everything. Do you want to carry Hydrogen and Oxygen into Space or carry Oxygen, Hydrogen and Carbon Just a hint, look at their atomic weights. Nuclear is even more of a problem, fuel cells don't last that lon <div class="Discussion_UserSignature"> </div>

arobie · Apr 8, 2005

Scott, A cornerstone of this plan is using ISRU to make propellants. If I am as up to date as I would like to think I am, we have not seen one drop of water on Mars yet. There is evidence of past seas, and we believe there is water there now, but we have no way of knowing how much there is, if water is even there. There could be underground oceans or there could be barely enough to survive off of as drinking water. We just don't know, and as of now it looks to be like the latter is a more likely scenario. If there is enough water to drink and to supply for propellant...I still would not like to use it as a propellant. Water is too valuable out there, and as a nessessity to live, I would rather not break it apart and throw it out of the back of our rockets if there is something else I could use, such as carbon. That makes in site resource utilization of water as a propellant an uncertainty about whether possible or not, and unlikley even if so. This all makes ISRU of carbon the likely choice of propellant manufactured at Mars. That in turn makes CH4/O2 the propellant we would have to use for our interplanetary boosters, since that is what we will be repropping them with at Mars. If we want to use the Hydrogen/Oxygen propellant as proposed, we would need to use not only the amount of propellant to get everthing to Mars, but we would have to send the propellant there to use in Mars orbit and to use to reprop the interplanetary boosters. We would have to supply all or much of the propellant for the entire settlement from Earth...which has already been determined to be a settlement plan that could not work. Remember, water is too valuable. It is not a Martian resource we would want to break up and burn. Using CH4/02 as our propellant of choice, we would only have to supply enough of it to get the first few cycles of payloads to Mars. After that the settlement itself will begin to make it's own propellant. It will not

scottb50 · Apr 9, 2005

If we want to use the Hydrogen/Oxygen propellant as proposed, we would need to use not only the amount of propellant to get everthing to Mars, but we would have to send the propellant there to use in Mars orbit and to use to reprop the interplanetary boosters....... Exactly my point. Don't forget getting down to the surface and powering a station, or colony, is going to take a lot of energy also. There is no way we will be able to produce energy, using extraterrestial resources, for a long time, ala Zubrin, until we see if we can, to begin with, and that we can do it and depend on it. Just the bulk and mass of the equipment needed, to produce CH4/LOX from the Martian atmosphere would take three, four or probably more, dedicated hardware missions to position. Then there is the time setting it up, in not very good working conditions, as well as putting it into operation and day to day maintenance. Sounds to me like starting out with two strikes against you. Additionally, you have to be concerned with carrying CH4 and LOX, which would both have to be liquid, to get acceptable volumes, until you are absolutely certain you can produce them in situ. Keeping them happy for a rather extended period, in conditions they don't normally exist in, is another problem. Hydrazine and Nitrogen Teroxide present even more problems, they are pretty reactive and don't store well. If everything is based on water it becomes a lot simpler. Water has a lot of other uses besides propulsion and has to be carried anyway for a manned mission. Water ends up being less mass, less storage and handling concerns, as well as simpler structure, it's a whole lot easier. On top of it, the mass and volume required to carry water is less than required of any other chemical propellant or power source and it can be carried in the same conditions people are carried in. After that the settlement itself will begin to make it's own pro <div class="Discussion_UserSignature"> </div>

spacester · Apr 9, 2005

Excellent post, Arobie! You understand the plan, you understand the big picture, you see why we have to make storable propellant. IMO the evidence to date is sufficient to make the assumption that we can extract at least enough water to produce enough H2 to serve as feedstock for the production of CH4. If we're going to settle Mars, we will also need to make drinking water. Shipping it all from Earth is not sustainable over the long run. IMO the prospects are good that we can extract that much water. <div class="Discussion_UserSignature"> </div>

spacester · Apr 9, 2005

Scott, way back in the thread I wrote: The problem with liquid Hydrogen is storage. Or lack thereof.

It simply leaks away, no matter what you try to do to stop it. Solving this problem is an unnecessary distraction, let somebody else do it and we’ll shift to LH2 when that tech is ready. Generating LH2 on the way to Mars is no way to run a spaceline. You’ve got to have assured dV capability to be able to do everything you need to do to get back, before you ever leave in the first place. I also question if LH2 can be generated at a fast enough rate with solar power to enable “gas and go” operations. Propellant: Kerosene/LOX if Earth derived, CH4/LOX if Martian derived. This is the baseline propulsion I’ll be working with until such time as I see some solid numbers refuting the above logic. It is noted that LH2 tanks will be very large, which is attractive from a habitat conversion standpoint, so if the storage problem is well and truly solved, we would go with the higher Isp, you bet. You keep insisting that we make our propellant as we go, and that solar will get the job done. My engineering instincts tell me that the solar array surface area and the power handling equipment will be prohibitively large and massive. Plus if you can't get the job done, you go flying past Mars and have mission failure. Manufacturing your braking system as you go is no way to run a spaceline. We need storable propellant. You make a completely unsupported statement that the mass requirement for CH4 / O2 production on the surface will be more than that for LH2/LOX. I hate to break it to you, but electrolysis and cryogenic equipment is not mass-free. As Arobie states very well, ISRU, specifically ISPP, is a cornerstone of the settlement plan. Mars needs to produce its own dV. Your wonderful little Hydrogen molecules leak through any storage vessel we can make. Bind it to Carbon and we can sto <div class="Discussion_UserSignature"> </div>

crossovermaniac · Apr 9, 2005

Colonization of Mars will be rather expensive. If there's going to be a large enough exodus to the Red Planet, then it would be a good idea to set up a manufacturing facility on the Moon to manufacture fuel and maybe even the structure of the spacecraft.

spacester · Apr 9, 2005

Experience gained while settling Mars will provide ample guidance as to colonization strategies. First things first. Note that IMO lunar settlement should happen concurrently with Mars settlement. <div class="Discussion_UserSignature"> </div>

tap_sa · Apr 9, 2005

I think the propellant issue should be settled now by a 'management decision' <img src="/images/icons/wink.gif" /> There has been a good discussion, many good points raised. Couple moot points IMO: First, availability of water on Mars. AFAIK it's beyond reasonable doubt that there is abundance of water in the polar caps. Even with CH4 you are going to need water for the hydrogen. Second, storability. While back I tried to dig up boil-off rates of hydrogen tanks and found this description of a study made for NASA in the 80s. I was amazed how low the boiling rate was, less than 4% per month for LH2. Note that this is LEO, tank unprotected from sunlight and no regenerative cooling. I calculated that even with abysmal 10% cooling efficiency the power required to reliquify boiled hydrogen is less than one kilowatt. The presented options with some pluses and minuses: Electrolysis rocket + transporting propellant from Earth/Mars easiest + dense and easy propellant storability - requires at least several megawatts of continuous electric power while firing, feasible but unproven. What source? solar panel, solar dynamic, nuclear? - electrolysis of this large scale in space is unproven technology LH2/LOX - LH2 requires huge tank and possibly active cooling + said big tank might be perfect radiation shield - transporting propellants (LH2) most difficult (unless transport batches of water and electrolyse it into main tanks, while orbiting Earth/Mars) + fuel cells might provide easy energy and water while enroute LCH4/LOX - LCH4 more complex to manufacture, needs electrolysis of water plus Sabatier process. - performance ~3/4 of LH2, more mass required + relatively easy storability, LCH4 is six times denser than LH2 and boiling point even higher than LOX + probably best fuel for Mars shuttles anyway

spacester · Apr 9, 2005

Thanks for the excellent summary, Tap_Sa That pretty much is exactly my thinking. I have already made the executive decision in favor of CH4/LOX, reluctantly, but remain open to LH2 if someone can make a solid case for it. The most important criteria in any tech selection for this settlement plan is the ease of development. We should not be selecting any technology that has a difficult development path. Perhaps the biggest problem IMO with CH4 is that AFAIK at this point in time there is no such thing as a rocket engine designed to use it. But considering that AFAIK we need to do some engine development anyway, it's a clear winner because we lose almost no mass over a storage period of months and years. Waste not want not. <div class="Discussion_UserSignature"> </div>

JonClarke · Apr 9, 2005

I agree, water on Mars is abudant, taking it to Mars is coal to Newcastle. Just to remind everyone again of the range of water resources on Mars 1) Atmsopheric water - low levels but near saturation and ubiquitous, very easily extracted. CONFIRMED RESOURCE 2) Hydrated minerals - large areas of layered sediments contain 5-10% water at the surface. Can be extracted by simple heating in solar or microwave furnace. CONFIRMED RESOURCE 3) Polar caps - predominantly water ice or water-CO2 clathrates (which are 5/6 water). CONFIRMED RESOURCE 4) High latitude shallow ground ice - latitudes above 60 north and south contain at least 40% water by mass within the top metre. CONFIRMED RESOURCE 5) Low latitude shallow ground ice - although shallow ice is not stable at low latitudes at present, Mars goes through climatic cycles like earth. During some of these ice is stable and can form at low latitudes. A number of features at low latitudes point to the presence of shallow ground ice in localised areas INFERRED RESOURCE 6) Deep ice. Deep ice is (several 100 m) is inferred to present at patchily even at the equator on the basis of rampart craters. INFERRED RESOURCE 7) Snow and glaciers - there is abundant geomorphic evidence for present and recent low and mid latitude glaciers on Mars in scattered localities - Dao Vallis, the large volcanoes. INFERRED RESOURCE 8) Shallow aquifers - the recent gullies in many craters point to at least localised relatively shallow (10-100's of m) aquifers. INFERRED RESOURCE 8) Deep aquifers - there is abudnant evidence for widespread very large deep aquifers. INFERRED RESOURCE. Obviously water supplies must be located and their quantity and quality determined, but I suggest when we committ to a Mars settlement we will know this from earlier missions or they will be located early on. Jon <div class="Discussion_UserSignature"> Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars Arthur Clarke </div>

scottb50 · Apr 10, 2005

Maybe I didn't make it overly clear. I would use LH2/LOX for major propulsion only, all other uses would use low pressure gasses. By the time LH2 or LOX gets to a fuel cell or thruster combustion chamber it is a gas anyway, nothing says it has to be liquid, just supply the right amount. The same system could power cars today: Nuclear produced electricity supplied to your house where a hydrolizer produces Hydrogen and exhausts Oxygen. Hydrogen gas is stored and transferred to vehicles for local driving needs in your garage. Commercial outlets could provide LH2 for extended trips. The best part is you can convert current vehicles as supplies increase. There's a lot of room in the trunk of a 59 Caddy. What I propose is using solar power to hydrolize water and produce gasses that are stored and transfered under relatively low pressure. Fuel cell and hydrolizer layers, inside a sealed structure, could be built in any number of layers. Water and power in, electricity and water out, everybodies happy, chemically. As long as we have a Sun, water and are around and able to repair and replace components, it works, but that's a given in Space. The need to store huge amounts of cryogenic propellant would not be needed, for extended periods, like they would be if you used Methane. In Mars orbit water would be broken down and sent to the surface, if usable water is found, it can be sent into orbit to allow larger payloads from Earth. Any liquid, except water, needs cryogenics to keep loses down. It would take pretty huge tanks to carry Methane gas, Zeppelin size at least. As I understand it, to produce CH4, on the Martian surface, we have to bring along our own Hydrogen. CO2+4H2=CH4+2H2O. To get Oxygen, according to Zubrin: "The water produced is condensed and then transeferred to a holding tank, after which it is pumped into an electrolysis cell and subjected to the fam <div class="Discussion_UserSignature"> </div>

kdavis007 · Apr 16, 2005

Well count me in..

dan_casale · Apr 18, 2005

I'll work on another summary post. Maybe from that we can figure out what step is next.

smradoch · Apr 19, 2005

How would you collect this water? Give me some clue how to do that? I somehow cann't imagine that you can easily collect several tons of clean water at Mars. I don't now if you want to mine water from the first Mars mission, but if so just name few equipment which would be neccesary for that mining.

nacnud · Apr 19, 2005

Ever heard of a solar still? If the ice is close enough to the surface that might be all you need.

smradoch · Apr 19, 2005

Ok if you would have soil containing water ice you have to collect soil somehow, warm that (in closed tank - otherwise vapour will flow away to space) and condense steam. So there will be lot of soil moving - lot of equipment. It can be done. You need closed tank, lot of sunshine and heaters, some cooling loop or cooldown during a night and some heavy machinery and lot of time. What is the content of water ice in the soil and how easily can you get it into your apparature is unknown. How much of water has to be produced and in what time?

grooble · Apr 19, 2005

Is it possible to send some kind of robotic lab, so that the time the humans arive, there is tons of water ready made?

ldyaidan · Apr 19, 2005

You're talking about assembling the ship in orbit. What about all the space junk that's already up there? How much of that can be picked up, and packed away, to be reused once on Mars, or the Moon? It's already there, and even if it's just used as scrap metal, it's stuff we don't have to launch, and will clean up some of the debris that they are starting to worry about. Also, if you go with a 28 person crew, will any of these people be staying on the ship in orbit, or will all of them be planetside? A crew in orbit will be able to stage rescue missions/etc, in case of any problems. Due to the low gravity, if the orbital ship has spin gravity, then by rotating crews, at least at first, then it might help reduce the problems caused by the low gravity. Would a "gravity chamber" planetside be possible? Not necessarily for the entire colony, but just in specific areas, that can be spun. Perhaps the workout area, or recreation area? I'm not a rocket scientist by any means. These ideas may not even be possible, but just adding my 2 cents

ldyaidan · Apr 19, 2005

Also, it seems it would be more practical to send a small machine shop, and raw materials for what you want/need to make, and make it once you are there. Would save on cargo space, and wouldn't have a bunch of stuff laying around that you don't need yet. Then you can take the raw materials, and make what you need, when you need it.

quasar2 · Apr 19, 2005

www.mobilepartshospital.com this or a version like it needs to be in OuterSpace right now. probably even more than one. put one @ L1. another on the Lunar surface, i don`t even have to stress the need for one on the Martian surface, that`s a given. <div class="Discussion_UserSignature"> </div>

Let's Design a Settlement for Mars!

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