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#5951 Re: Life support systems » Turning structures like Mount Sharp into Martian Cities. » 2014-12-17 14:53:29
I feel that there are many reasons, to at least imagine how Mount Sharp could be turned into a very large population city on Mars.
I have been pondering this for a while, and to me the advantages just keep piling up.
First of all we have a probe there which may find significant "Ground Truth" about the place. (For GWJohnson)
It is near the Equator, so fluctuations seasonally are muted, and with the exception of dust storms, solar flux is predictable without large seasonal gaps, and of course the temperatures are about the best for Mars.
It appears to be made of layers of sedimentary rock, deposited by Rivers, Lakes, and Wind/Damp.
Some of these layers could be suitable for carving habitats into, that is, they may be suitable sandstone.
Some layers may have been deposited under neutral PH water conditions, and further up, perhaps some may be deposited under acid water conditions. So, it might be possible that the "Blue Berries" that one of our members champions for Iron/Steel making may be present in one or more layers.
The lower layer sandstone may be glued by clay. This could be important because clay and porous objects absorb water vapor. So, it may be that some carved chambers could be used to extract water vapor. Without applying Vacuum (An Option), but by heating the interior, the Relative Humidity of the air inside will try to maintain equilibrium with the hydration of the sandstone. For every 20 degF that the air is heated above ambient (Sandstone) the humidity carrying capacity of the heated air doubles (I think). So you don't have to look to hard to see where I am going with this. Mount Sharp at least in portions may be an enormous humidity trap. Means to extract water from it are as stated before, and could be supplemented by adding a negative electrical charge to the interior of the collection "Cave".
As for energy. Solar would be assisted by the tilt of the Mountain. Less structure needed since portions of the mountain are at a proper slant, and orientation to the sun. Atmospheric power. If the O2 and CO of the atmosphere can be utilized in some way then that is certainly available on Mt. Sharp as well.
As for Green Houses. I would consider an open rectangular cut into the face of the mountain, and a curved glaze where the concave side points outside, and the convex side is on the inside.
Mushroom Houses: If you have a ledge, then you can carve a tunnel from the main cave habitats to the center of one of GW's Mushroom Houses.
Other greenhouses. Could also be connected through their floors in the same way with a network of tunnels and caves created within Mt. Sharp.
So, I support this now because it greatly reduces materials required for construction, but is rather flexible.
And it has a Plenum or Common Plain. This is something like a ground plain in an electrical circuit. Each structure has connection to this common, but can also deviate or be unique for a purpose.
The location is also favored because in the event the planet is terraformed, then snow pack might appear on the top of the mountain, and then snow melts would provide a additional water supply, maybe even a lake again.
I would agree this is a good candidate for a settlement and I like most of your suggestions.
#5952 Re: Human missions » Boeing's plan for Mars » 2014-12-14 14:56:13
louis wrote:This link no longer seems to be working...odd.
Has anyone saved the slideshow?
Found it in my internet cache. click here
Thanks Robert.
#5953 Re: Human missions » Boeing's plan for Mars » 2014-12-14 05:47:22
Ok. I found the slides. It's actually in .PDF format, so you can use Adobe Reader to view it.
click hereI notice a few slides have the Energia logo. Most people on this forum are familiar, but for those who don't know, that's a Russian big aerspace company. They made the Energia rocket (yes, same name), as well as a lot more. I was all for partnership with them after reading Robert Zubrin suggest using their big rocket in his book "The Case For Mars". But the Ukraine thing killed that. How would Energia participate in this plan?
http://www.energia.ru/ru/images/energia_flying.gif
This link no longer seems to be working...odd.
Has anyone saved the slideshow?
#5954 Re: Human missions » Boeing's plan for Mars » 2014-12-14 05:42:28
I was just looking over the Boeing plan again.
Louis: There is a pre-landing of supplies. Two years before the humans are launched, two SLS are launched with ion tug and a cargo lander. The cargo lander takes almost two years to get to Mars; it uses a higher ISP krypton system, which saves fuel but takes a lot more time because the thrust is much lower. Several slides show the cargo lander, which appears to have a transit hab on top, so it provides the astronauts their home after they land on Mars. Another slide shows a sort of garage near the cargo lander and several surface vehicles. The crew ascent vehicle is indeed very small and light. That's why it can get to a high Mars orbit. Presumably, spiraling the entire interplanetary transit system from a low Mars orbit takes a long time and a lot of krypton (the solar panels and ion engines are heavy because of their size).
The first human mission takes 5 SLS launches; 2 to get the cargo lander on its way to Mars, then 3 (2 years later) to get the humans on their way. Presumably subsequent missions could reuse the solar electric tug and transit hab, so perhaps subsequent missions would require only 4 launches.
THAT'S the big problem the Boeing Plan has. Why develop a solar electric tug when Space X can launch kerosene or methane fuel cheaply and push everything to Mars the old fashioned way? They're already developing technology for a Mars lander; I just saw the other day that someone else (Boeing?) wants to develop a launch escape system built into their capsule. The Boeing Mars Plan is very attractive, but it has ignored (it had to ignore!) the revolution that is coming.
Thanks for pointing out the pre-landing element. I'll take a closer look at that.
I agree with your conclusion about Space X. There is clearly a lot of "politics" here. We may be getting into the area of "pork barrel" politics with this project really being more motivated by the need to maintain work at Boeing factories rather than a rational assessment of how best to proceed with a Mars mission on a cost-benefit analysis.
#5955 Re: Human missions » Boeing's plan for Mars » 2014-12-11 07:32:36
Some initial thoughts:
1. This mission plan appears to ignore the potential of pre-lander missions. I think there is a lot to be said for pre-landing supplies, inflatable hab, pressurised rover and PV panelling. One of the main advantages is that your lander craft can then be much smaller. You can also pre-land the ascent craft. You can also check that everything is there and working before you commit to putting humans on the surface.
2. Suited EVA elements are not necessary if you choose to do your exploring and work (e.g. ice mining) in a pressurised rover. Are we sure we are not being misled here by the glamour of footprints in the dust.
3. The mission seems light on ISRU. Although Mission 1 won't be self-sufficient, the amount of PV panelling in play seems to be pathetically small. Again, that's an argument for pre-landing.
#5956 Re: Human missions » Boeing's plan for Mars » 2014-12-10 19:58:39
Some of the best graphics I have seen and obviously a very well thought through mission plan, which I am going to study in more detail.
Is it their attempt to get ahead of Musk or stymie him?
#5957 Re: Life support systems » Extracting moisture from Martian atmosphere » 2014-12-01 19:05:32
This paper http://www.uapress.arizona.edu/onlinebk … rces28.pdf seems to have a nice Acetylene/CO/O2 propellent mix which is just 1% Hydrogen by weight and hits the same impulse as Metho-Lox. They even recommend extracting moisture from the atmosphere (10^6 m^3 of atmosphere would yields 1 kg water by simply compressing it). A big industrial size fan doing 700 m^3 a minutes would move that volume in a day (as far as I know the volumetric efficient of a fan should be unaffected by the low pressure on Mars).
That is probably going to be too large a compressor and too slow an extraction rate for any kind of initial mission, but when were talking about a long-term sustained fleet of reusable Mars Taxi's that need to be fueled entirely on Mars using some hydro-carbon fuel it may be simpler then an ice mining operation as it is just a static machine that won't be breaking down the way mining equipment inevitably dose.
In this paper https://www.google.com/search?q=moistur … channel=sb the design of a zeolite moisture absorber optimized for Martian atmosphere is discussed, as the process is passive the energy requirements are just that to push the the air-stream through the zeolite which should be manageable. A more detailed design is here http://www.lpi.usra.edu/publications/re … ington.pdf which claims to be able to get several kg a day with just the a small fraction of reference mission available power provided that altitude is low, in the north polar zone the rate of production shoots op an order of magnitude due to humidity.
Finally this http://www.uapress.arizona.edu/onlinebk … rces29.pdf (again from my old school UofA) looks at the whole spectrum of atmospheric separation and the energy costs their of. For human life-support the energy costs are reasonable as people only need on the order of 1 kg of these inputs per day.
Air-moisture extraction in the desert like environment of Mars reminds one of Arakis from the Dune novels dose it not. The fact that you can just drop the base anywhere without scouting for ice and have high confidence in the equipment because we can test it so thoroughly here on earth is very attractive. Their would also be no issue with ever running out of what ever glacier your mining. A base that exhausts resources like that is going to become a ghost town.
Couple of thoughts:
1. Whilst not opposed to atmospheric extraction, sending robots to scout for water shouldn't be too difficult. So far none of the space agencies have chosen to send robots to where water is most likely to be found.
2. I think there is a strong possibility quite a young Mars community could build Armadillo style rockets that could get to LMO.
#5958 Re: Home improvements » Indoor farming update » 2014-11-29 19:37:42
louis: I'm assuming that shelves can't move past each other and that the growing plants on each level would get crushed if we tried to compress all the lower shelves to bring a high shelf down to ground level. I imagine each shelf moving within a ~6 foot range, not because of any limit in their cog-rail system, but simply to prevent crushing of plants. Now if you really wanted to go with some kind of loop system, a bit like thouse ovens that donuts rise in then you could bring any shelf to ground level but that would complicate things on many levels, mechanical, electrical and watering. I think the simpler approach may be desirable here, particularly when the first system is likely to be no more then 6-8 foot tall, the 25 foot tall towers are a good deal further out and aren't needed until your feeding dozens or hundreds I think. I'd imagined stair-cases being made of carbon-fiber or aluminum, nothing sounds less safe then an inflatable ladder, the ultimate vertical farm perhaps uses a picking robot that brings trays down and to a human work area, much like a modern warehouse or distribution center.
Not sure I have quite grasped your proposal - I was indeed of the view you were thinking more of something like a donut rack system.
One question: does it have to be automated? Is there any reason why a person on the ground couldn't activate movement of the racks on a chain system.
I agree about the first trial only being 6-8 feet high.
Robots are coming on at speed, much faster than most people realise and of course the high cost of robots would be irrelevant for the early Mars missions, so robots might well have a part to play.
I am not sure an inflatable ladder is necessarily dangerous. It could be built with inflatable guard sides, so that the worst that happens is you bounce down to the (inflated) bottom. I think stability for useful work rather than safety would be the key limiting factor. What we call "bouncy castles" in the UK have really high inflatable sides BTW.
#5959 Re: Home improvements » Indoor farming update » 2014-11-29 06:30:21
Great post Impaler - some v. interesting ideas.
If the trays can be moved mechanically though, do we need any ladder or staircase for harvesting? Of course, you might get mechanical failure.
I do agree that one of the key tasks required with respect to a human mission is to undertake an absolutely thorough health and safety analysis. Injuries must be kept superficial and minimal. Everything from cooking to harvesting to mining to life support systems and exploration will need to be analysed to nth degree.
And/or, I wonder if you can have an inflatable staircase?
Another point in favor of stacked artificial lighting set up like that in the OP.
Adjustable shelving heights for the growing racks, a batch of crops spends most of it's life-span at far less then it's final mature height and plants in artificially lit situations generally benefit from having the light source brought to just a few inches from their top most leaves. So having a kind of accordion cycle in which a succession of crops are grown with the racks moving further apart until a mature crop in harvested and it's rack is replanted and the space above it redistributed to the others. This arrangement should be able to produce another rough doubling of overall volumetric density.
Their is also the advantage of being able to temporarily move a pocket of space around to facilitate human examination (LED's generally switch to white light levels to do this so the human eye can see the plants normally) and harvest of the tray, as this is a very short term activity the space could literally be 'borrowed' from other levels by momentarily compressing them to below optimum levels, the leaves of other levels might just brush the LED's and if need be they can be shut off for a few minutes to do this without any real damage to . The picked tray of plants would then be immediately re-sown without removing it from the vertical system.
The mechanical system to move the levels would likely be some kind of cog-wheel and locking-pin that engages with a vertical rail, 4 rails and 4 cogs per level. Each moving shelf would have LED's in the bottom of it and likely a ventilation system that both cools the LED's and blows across the plants to develop robust stems, the top of the shelf is a flat waterproof surface and the growing tray is a fully separate system that simply sits on top of it. The lights, fans and servos for the cogs are all powered and controlled by a single wire running to a simple plug in another vertical column dedicated to electrical power, the wire simply has sufficient slack to accommodate the maximum range of movement of the shelf. Growing tray water systems are likewise supplied by flexible tubes emanating from a vertical plenum with sufficient slacks to accommodate movement, pumps located in the plenum and under computer control do all watering meaning the tray systems and watering systems are kept separate. All the system parts disassemble into compact forms, the shelves, stack flat, the rails can be bundled and then snap into floor plates, the electrical and water plenums likewise bundle, growing trays should nest. Throw in some central water/nutrient/air handling systems and any growing media/fertilizer and you have a full turn-key system. A simple unpressurized cargo container should be able to hold all that and, the only thing not included are the seeds which may need to be pressurized and chilled and radiation protected so I would basically treat the seeds as 'crew' for logistical purposes aka they get to ride the fast-transit and all the protection of biological systems that we can manage, fortunately they are so small we will hardly notice them tagging along with the crew.
The whole system when packaged should be just a small fraction of it's final volume, so it will pair very well with an inflatable structure such as a Bigelow/TransHab system, as these system become progressively more mass/volume efficient the bigger they get I think something on the 1-2k m^3 may be what's desired (for both growing and living space), as this is just an empty pressure vessel it should mass . The inflatable might not be the traditional cylinder that's been the go too choice for in-space human habitation, rather a planetary surface a more rectangular shape is better, a Quonset hut style shape may be a good compromise as a tall vertical space is not much of a problem as the 25ft vertical space in the OP's link indicates. The human harvest is the only issue and I'd mitigate the danger of a ladder by using a kind of flat topped staircase that fits in the aisle, these are fairly standard in warehouses and are fairly idiot proof, worst case tumble down a staircase is much better then falling off a ladder.
#5960 Re: Interplanetary transportation » Amortizing reusable Mars Transports » 2014-11-22 20:35:12
From everything I have ever read on this subject, I agree with GW.
I suggest you follow Elon Musk if you want the cheapest way to launch. He is completely devoted to delivering the cheapest possible launch system...he's not looking to maximise profit from that point of view.
If his reusable launcher systems go to plan we should see some further substantial falls in launch costs. I think Musk thought he could get it down to $500 per pound. He may be right.
When you compare that with $30,000 per pound for Space Shuttle launches we can see we are in game changer territory as regards getting to Mars.
Impaler:
Looking at published launch prices and max payload capabilities (to LEO) for all the launchers (every country) produces a very interesting curve. The commercial launchers (subject to price competition) are all in the vicinity of $2500/lb at 10-20 tons. Spacex's published data for Falcon-Heavy falls in the vicinity of $1000/lb at 53 tons. If you extend/extrapolate that trend, the unit price should be at or under $500/lb at around 100 tons. It's probably nonlinear, but still, way under $1000/lb.
Yet NASA's best estimates for SLS fall in the vicinity of $2500/lb, which you have to take with a very big chunk of rock salt. Their history of estimating costs is abysmal. That's the difference between a government-run design and commercially-competitive designs.
From all that I conclude SLS will never be cheap: what's the cost difference between 100 tons launched to LEO at $2500+/lb on SLS, and 100 tons launched in five 20 ton chunks at $2500-2400/lb on ULA and F-9 rockets, and docked together? Not much. Not much at all.
The noncompetitive historical government missile-derived launchers like Titan-IV fall 4+ times higher than the commercial curve. The one-and-only routine spaceplane (shuttle) delivered about 15 tons for a $1B launch price: around $30,000/lb.
Skylon might (maybe someday) do better, but its inherently small payload fraction will preclude “cheap” commercially-competitive use as a tanker, which needs to be lots of tonnage. Spaceplanes will have a niche for small payloads only. Like crews.
So Spacex, ULA, their foreign counterparts like Ariane, and maybe(!!) NASA's SLS are what you have to work with for missions to Mars or anywhere else outside cis-lunar space, now, and for the foreseeable future. Period.
And, you have to consider achievable flight rates. Falcon-Heavy will be cheaper, yes, but not very many of them will be available for a long time yet. Spacex is having trouble keeping up with the Falcon-9 business it has already booked. This shows in slipped launch dates.
There might (or might not ever) be an SLS flight rate of 1 per year.
ULA actually has the highest flight rate, primarily because it has two rockets built in two different factories. But that won't last. ULA will soon have to replace the Russian engines on Atlas-5, due to the bad international relations we will be having for the foreseeable future.
The space station was a $10B+ item precisely because most of it was assembled from 15-ton items launched at near $30,000/lb. The same job could be done commercially today with 15-20 ton items at $2500/lb, which would slash the launch price by more than a factor of 10.
Looking at that overall picture of what's available and flight rates for the foreseeable future, I don't see any future in waiting for SLS which will most likely be several times more expensive than we have right now, or for the inexpensive Falcon-Heavy, whose flight rates cannot sustain a large effort. To me, that picture says use what you have now, or you'll never fly at all.
So, I disagree with your statement that current commercial rockets are "staggeringly inefficient". They are quite demonstrably the most cost-efficient means that we have. Further, smaller launchers will never be cheaper per pound. If you add Falcon-1 to the curve, it's above $4000/lb at 1 ton size. So bigger really is better, but you must use what you have. And the commercial unit prices are simply the very best available, by at least a factor of 4.
GW
#5961 Re: Home improvements » Indoor farming update » 2014-11-15 20:07:31
I think the idea that the first Mars colonists will be popping in and out of suits is ridiculous. There's no need. People will stay in an artificially pressurised environment nearly the whole time. When move between pressurised habs they will travel in pressurised vehicles. It's so much easier than any other approach, that I can't see any other approach being adopted.
Of course there will be walking on Mars but it will be rare to begin with. It will probably only really take off with tourism when people will want that walking and "fingerpads on stone" feel to their experience.
But for the first colonists there is simply no need to get into that dangerous territory of moving in and out of suits.
#5962 Re: Human missions » The Martian by Andy Weir » 2014-11-15 20:02:52
Dust storm punctured his suit? I don't think so! Not realistic.
#5963 Re: Home improvements » Indoor farming update » 2014-11-11 13:49:11
Good work Impaler! At 32kWh per person per day, a 1400MWe fast breeder reactor can produce enough food for 1million people per day. A result that suggests that human beings equipped with a nuclear power supply should be able to live just about anywhere where there is a sufficient source of energy.
The same applies to PV power for Moon and Mars. But with PV you can split it up and use it where you need it. If one part goes wrong, there are plenty of other parts to go right. A single nuclear reactor means you are putting all your eggs in one unwieldy basket.
#5964 Re: Human missions » Foster and Partners' Plan for Lunar Module - Looks good for Mars? » 2014-11-10 13:24:36
Oh btw, how do thouse little Copula things get into the inflatable part? They don't show them in the inflation scene, but you have to manufacture in anything that interrupts the integrity of an inflatable structure, you can't cut into an inflatable to add it later.
Maybe they don't interrupt the inflatable structure but are just placed over pre-existing transparent sections of the inflatable. In any event, they provide a pathway for radiation to enter the habitat and presumably more vulnerable to micro meteorites too. But GOTTA HAVE THAT VIEW OF THE EARTH!!
Yes they did look a bit odd. I would personally favour a completely sealed hab (excepting the airlock of course). Better to have TV screens to relay the view from outside.
#5965 Re: Human missions » Mars One » 2014-11-10 13:21:25
Creating closed ecological systems is not helpful. There is no reason why the Mars Hab has to be closed. We can import gases and materials and vent them off/dispose of them as well.
#5966 Re: Human missions » Mars One » 2014-11-10 07:28:57
Attempting to achieve food self-sufficiency from the get-go is to my mind a waste of time and effort.
Delivering food supplies to the base should not be problematic in the early stages. You could pre-land a few tonnes of food: maybe (given a lot could bed delivered as low weight items e.g. dried food stuffs, vitamin pills and highly calorific oils) allowing a little less than a kg per person per day (sol). So a six person mission would need only about 300kgs per person per annum = 1800 kgs, under two tonnes for a year.
The base could begin with growing salad vegetables which would be relatively easy - it's already done regularly at Antarctic bases - to supplement the basic diet.
#5967 Re: Human missions » Foster and Partners' Plan for Lunar Module - Looks good for Mars? » 2014-11-09 20:09:28
That was my best guess of what you meant! LOL
I think it's just promotion as in 3D sounds "sexy" whereas "robot vehicle spreading dirt for three months" doesn't. 
Your criticisms are fair enough I think. A couple of settlers in a pressurised bulldozer would probably complete the task in a couple of days.
Tom Kalbfus wrote:Impaler wrote:For me 3D printing is for me the 'Godwinization' of any proposed technological architecture, it immediately loses credibility.
Don't you mean the Goddardization of any proposed technological architecture?
http://siarchives.si.edu/history/exhibi … et-pioneerNo I mean http://en.wikipedia.org/wiki/Godwin%27s_law aka When you compare someone to Hitler you lose credibility. When I hear 3D printing I feel something loses credibility because 3D printing is massively over hyped technology and most of the people hyping it THINK that 3D printing is a substitute for a whole Machine shop and the whole set of skills, machines and infrastructure that allow us to make our whole set of complex and high performance equipment that we need to live in space. Most people who think this know absolutely NOTHING about manufacturing or quality control. In reality 3D printing is just another technique that will take it's place within the pantheon of manufacturing techniques, just as we continue to use EVERY other manufacturing technique like molding, forging, injection, cutting, welding, reaming, boring etc etc, we will need to bring ALL of that with us if we expect to have the ability to make replacement parts (to speak nothing of Raw materials). As someone with actual experience in QC and from a Tool and Die making family, I have complete disdain for people who don't know what they are talking about and dismiss our manufacturing base as obsoleted by one device. This is like saying we don't need to bring a doctor to Mars because we will just use 'Stem cells' when ever someone becomes sick.
Further more my main criticism of this Moon base 'regolith printing' nonsense is that their is NO POINT to using the technology for the task, that of covering an inflatable structure with protective regolith. A KISS Bulldozer will do just as well and use about 2 orders of magnitude less energy, a simple bulldozer rover can probably be simple solar-on-back (operating only during lunar Day), something trying to use microwave sintering will probably need to be nuclear. And that's before even looking at having to mix aluminum with regolith as SpaceNuts's link suggests (I'd always heard that it *should* be possible with unadulterated regolith). The only justification for that kind of energy expenditure is if I can build the entire PRESSURE VESSEL from regolith, essentially making our own lava tubes to move into. But if I already brought my pressure vessel from Earth, forget about it.
Bigelow depicts a far more sensible way to do this in their inflatable Moon base concept, they just have a strip of bags filled with regolith that are then presumably pulled across the habitat and drape over it. The bag material should just come in two long strips and be heat welded together along the edges much like how potato-chips bags are closed minus the cutting apart of the individual bags, and this would be VERY simple to do in a robot, just box scoop the regolith directly into the bagging assembly and drop the growing bag-strip behind the vehicle, this is very much how a the bags of ice you buy at a Gas-station is made. This is probably even more energy efficient then the simple bulldozing of a heap because the bags can hold the critical regolith on top of the hab in place without using tons of material in talus slopes up the sides of the habitat which don't contribute to radiation protection.
#5968 Re: Human missions » Foster and Partners' Plan for Lunar Module - Looks good for Mars? » 2014-11-09 13:39:55
I remembered something on lunar bricks and searched for a bit...
Moon-Rock Bricks Could Build Lunar Bases and Settlements
A Virginia Tech team might have the answer to the lunar base construction challenge: build a dome of moon rock bricks using the material that's already there.
Going under the name "Masons of Regolith," the seven Virginia Tech students used a kind of volcanic ash similar to regolith from moon rocks to build bricks that could lay the foundation of a moon dome. Doctoral student Eric Faierson says the simulated regolith (which came from NASA) is volcanic ash mixed with other materials to mimic moon rock. The team combined the faux moon ash with powdered aluminum and mixed the two together in a silica crucible. Then the group put a nickel chromium wire into the mixture and heated it to 2700 degrees F, starting a thermite reaction that spread through the mix and turned it to solid brick. All it takes is heating the mixture to aluminum's melting point, about 1221 degrees F,
That could certainly be the way to go once a base is established.
#5969 Re: Human missions » Foster and Partners' Plan for Lunar Module - Looks good for Mars? » 2014-11-07 07:14:16
The article covvers some of the very topics we have had quite a bit of discusion on...
A home of our own - on the MOON: European Space Agency reveals plans for first human settlement outside Earth - and says inflatable base will be made by 3D printing robots
3D printing technology will transform raw lunar soil into livable domes, covering inflatable structures
Will house four people and protect them from meteorites and gamma radiation
Could be ready for humans to move in within the next 40 years
I see that the base is built from insitu materials, Done by robotics...
Yes - it's not quite what I think of as 3D printing - essentially robot controlled vehicles working to software...maybe guided by radio beacons set around the habitat??
#5970 Human missions » Foster and Partners' Plan for Lunar Module - Looks good for Mars? » 2014-11-06 17:51:37
- louis
- Replies: 18
http://www.dailymail.co.uk/sciencetech/ … obots.html
Take a look at the video - from 2.20 it shows how the lunar hab would be built.
Should be good for Mars as well.
#5971 Re: Planetary transportation » Martian Transportation Infrastructure » 2014-11-04 18:42:26
Inert material such as ores could be transported over distances of 500km using a gas gun. The weaker Martian gravity and tenuous atmosphere would allow ranges for ballistic projectiles that are unachievable on Earth.
A smooth bore gas gun would show significant dispersal over that sort of range, but if you are prepared to set aside 30km2 of Martian desert as a 'target area' you could allow projectiles to accumulate for several months and simply collect them at the end of the year.
Excellent idea.
However, I think from a practical point of view, it's probably just as easy (since you've got to collect the stuff anyway) to have robotic solar powered vehicles ferrying materials from mining sites etc. They don't have to travel at speed. Once you have your chain supply established, speed becomes pretty irrelevant as long as the supply is constant.
Routes can be cleared of boulders by specialised bulldozer vehicles at the outset to facilitate wheeled transport.
#5972 Re: Interplanetary transportation » Habcrafts and Cyclers » 2014-10-19 17:32:26
Antius wrote:Since the original Case for Mars was written, it has pretty much become accepted wisdom that a reusable chemically fuelled SSTO is not workable as an economical rocket, for all the same reasons that the shuttle was unworkable economically.
It was also "accepted wisdom" that the world was flat.
It was "accepted wisdom" that no aircraft can fly faster than the speed of sound.
It was "accepted wisdom" that you cannot propulsively land on Earth, because fuel to do so would be prohibitively heavy. You require some sort of aerodynamic process to slow down, and approach the surface at a controlled rate. That could be a parachute, or wings, or lifting body. The chief engineer for Gemini tried to develop a "wing" that could be deployed like a parachute. He failed, so a conventional parachute was used. However, others continued his work and both the hang glider and parafoil were developed from that work. But the kicker is Dragon v2 does land propulsively.Original requirementss from NASA for the Space Shuttle were a fully reusable Two-Stage-To-Orbit vehicle. It would carry 11 metric tonnes to a space station in 400km orbit at 50° inclination. That's so close to the orbit ISS is in today that the difference isn't worth mentioning. This TSTO Shuttle would have a lifting body orbiter, and piloted fly-back booster. That means the booster would have an aircraft skin over insulation for the external tank, so no problem with foam. And no SRBs. Nixon demanded NASA and the military combine funds for a single launch vehicle, which created a Frankenstein's monster that wasn't good at anything. The Shuttle was changed to a delta wing so it could fly over the pole, but ironically it never did. The cargo hold was expanded to be large enough to carry the K7 spy satellite, and Shuttle was bulked up so it could lift 28.8 tonnes to 185km orbit. Shuttle requirements stated it would fly 50 missions per year, but after all the crap that was done to it, the maximum was 6 per year. Shuttle would have worked if it was built to original requirements.
I think this may be relevant to the discussion:
http://www.nasaspaceflight.com/2013/03/ … -missions/
Tie it into the Space X reusable rocket and perhaps you have a here a cheapish way of getting people to LEO orbit (from where they can be ferried to Mars) and bringing others back (from a Mars-Earth flight).
#5973 Re: Martian Politics and Economy » Martian Exports » 2014-10-18 10:42:59
As far as I see with Mars Exports not all that is Mars will be exported nor will it be just a made on Mars to be just used on Mars either. Fuels, Air and water made on Mars can be used for going deeper into outer space as well. Heck even the "Toyota-badged vehicles" being returned to Earth after its use would prove to be of great value....
That's very true. The vehicle would be worth millions back on Earth to a Museum. If a Museum can get an extra 100 visitors a day at $10 profit per visitor, that's over $300,000 per annum. Over 10 years, that's $3million, over 30 years, $9millions. And for a Museum, such additions to their collection can have a range of intangible benefits e.g. encouraging other benefactors etc.
#5974 Re: Martian Politics and Economy » Martian Exports » 2014-10-17 12:49:50
Louis, you're talking about $150 million/year. In the context of a Mars colony, that's... not very much. Perhaps if you write off the set up costs and give up on any chance of profit, you'll have enough to get the colonists supplied with what they need - for a decade.
I'm being conservative...but even on those conservative figures I think meteorite and regolith sales would be around $250 million.
If Musk is right and he can get launch costs down to $500 per Kg, that's 500 tonnes to LEO, maybe 125 tonnes to Mars surface - more than enough for a small colony in the early stages.
But meteorites and regolith are not the only thing Mars could sell to Mars. They are many other ways that we could
There could be life support for scientific expeditions for instance. Why wouldn't, say, a company like Toyota invest $100million over three or four years out of its publicity budget to fund say an expedition using Toyota-badged vehicles. That sort of publicity would be cheap at the price.
#5975 Re: Martian Politics and Economy » Martian Exports » 2014-10-16 17:44:56
If the fusion power becomes real, I have to agree with your thinking for sure Louis.
I think such trade would be profitable even on the basis of conventional rocketry - if Musk's programme of improvements (particularly reusable rockets) comes to pass, and I see no reason why not in the next decade or so.