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Okay, so we spend months getting all this sulfur and spraying a home and installing all the equipment. You would then leave the tuna can for the Mars habitat? Even if you would, that's not increased colonization. That's a lateral movement. The Mars population level stays exactly the same. Even if the settlers build 100 homes. How are you going to get 100 people to Mars without sending them there in a habitat?
We spend time BEFORE colonists arrive on Mars building and collecting the things we'd need to live on Mars. The tuna that takes the colonists from Earth to Mars is only large enough to hold 12 people for 90 days and it's possible to reduce that transit time to 30 days. The tuna can that takes the colonists from Mars orbit to Mars surface is large enough to hold 12 people for 2 hours. The cans don't have to hold everything required to live on Mars for the rest of the colonists lives if we make buildings on Mars.
The bunker will have been built by the robots, complete with airlocks and life support equipment, BEFORE the humans show up. The settlers will arrive in a tuna can the size of a small bus after they travel to Mars from Earth in a tuna can the size of a large house. That's the Boeing 747, Bus, and Base concept. I fly in the aircraft to the vicinity of my destination if it's very far from where I live, I take a bus to go to the exact building I want to visit, and there's a building at my destination when I step off the bus.
You're fixated on this building for every colonist idea, which is something I never proposed or even thought about. I said we could build more buildings and/or larger buildings. For whatever reason, you leaped to the conclusion that I was trying to give everyone on Mars their own villa or something. For efficiency's sake, everyone lives in the same bunker and eats at the same table, just like a prison.
The ability to build more buildings is the ability to construct more greenhouses, more consumables storage depots, and more maintenance depots to work on the reusable Mars orbit to Mars surface transports, construction robots, or other vehicles. I would insist that the colony be able to access all of its infrastructure without leaving the pressurized environment.
Oh, the ITS, right? You they're going to sleep in bags fixed to the walls and not have a living space of their own.
I don't have any plans that require something as large as ITS to start with, but ITS opens up new possibilities. Instead of sending something that large to Mars, I want to use the Boeing 747, bus, and base concept.
Where is the extra food going to come from? Don't you kind of need more greenhouses already growing plants before the people arrive? How does sulfacrete hold up as a greenhouse? Does the sulfacrete absorb moisture and soften in a humid environment? I bet it would.
The food is coming from the extra greenhouses built on Mars using sulfacrete. There's no mass penalty for building larger greenhouses or more greenhouses, whichever is desirable. If we can't grow food on Mars, then we're not going to send colonists to Mars just to watch them die slowly from starvation.
I bet sulfacrete wouldn't absorb any water, since there's a commercial product you can buy that says it doesn't: Sulfurcrete Sulfur Concrete Technology
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Robert Dyck
You would cut large blocks of ice and bring them inside a pressurized environment to melt? That will work but it's only efficient if there is a large ice deposit at or very near your base so you can use an ATV and towed cart to bring large blocks inside the greenhouse.
If you have to drive a long ways to get it the process then becomes too dangerous and inefficient because you lose some oxygen and pressure in your rover each time you open the hatch, even with two pressure doors. Also, your risking your lives every time you drive the long range rover far from base. If it breaks down or gets stuck, you die.
The Homestead Mars guys wanted to melt the ice deep down and keep and ice roof to contain the water vapor? Okay, the ice would melt and form a cavity full of water vapor but you still can't get the water vapor with a vacuum because you need the cavern to have some pressure in order for a vacuum to work.
And there won't be any water in that cave because there is no pressure. Melting ice is in an enclosed ice cave is not going to create it's own pressure because ice takes up more room than water does so, if anything, it will be more of a vacuum than Mars atmosphere has.
You would have a bubble in the ice that is water vapor but no way to capture the water vapor. You could dig a hole in the top and drop down a bucket into it and pull it up and then take it inside your rover to condense into water but we're talking about a few drops of water, not cups.
Also, once again, even if you do have a pool of water on Mars you can't suck it up with anything because Mars atmospheric pressure is almost zero. You would have to have a vacuum that is powered by a jet engine and even then it would take a while.
We're so used to the way things work on the Earth that it's difficult to stop thinking that way and think the Martian way. Water doesn't exist on Mars except between the time of 33 to 35 degrees, that's about 6 minutes each day near the equator. Whatever you are going to do to get it has to be quick.
I've seen your pictures of the Mars hillside settlement, I think we need to be more realistic.
Do I want to run detailed numbers? I don't like the idea of harvesting ice or attempting to get water on Mars. They need to bring all their water with them and limit the amount of time they go outside because every time they open the greenhouse hatch they will lose tiny amounts of pressure, oxygen, and water vapor. Those things are not easy to replace on Mars.
The settlements oxygen and water loss from the greenhouse and tuna can habitat should be almost zero. And, the greenhouse itself, once finished, will heat the regolith below and cause it to outgas some CO2 for pressure (not much, I know) and outgas some water vapor. So, we will have a slight gain in water.
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Dook,
It sounds almost as if you are saying that you constantly have to replenish water in your Mars greenhouse. I don't think you do, though, do you? It is a mostly closed system. The water evaporates off the leaves and presumably condenses somewhere...and can be collected thanks to gravity.
No. I never said you have to replenish water. I've said the opposite. You guys are the ones saying you need to replenish your water because you want to waste it on rocket fuel.
You don't have to replenish the water inside your greenhouse because it's self contained. You would never lose water except tiny amounts of water vapor that would escape each time you open the entry hatch. All the water you initially brought with you and use on your greenhouse plants stays in your greenhouse.
You don't have to go and get water. You have to stop thinking that using water is destroying it, water goes in a cycle. It's never destroyed unless you zap it to turn it into hydrogen and oxygen and make rocket fuel, which you shouldn't do on Mars because having the water is more important than sending something to the Earth.
So, in order to limit the loss of water, and pressure, from your greenhouse you should limit the amount of times you open the door. The same thing applies to your tuna can habitat.
The perfect scenario is this, move Mars regolith into a pile, assemble your greenhouse over the pile using the pile to stand on to assemble the greenhouse, finish the greenhouse, pressurize the greenhouse, water vapor will outgas from the regolith pile inside your greenhouse, collect the water into tanks, then use your regolith pile and water to make bricks inside your greenhouse. Bake the bricks to harden them and get all the water out inside the greenhouse using solar reflectors.
Then, once you have used up about half the regolith pile you would have some bricks. Now you can use those bricks to make a structure INSIDE your greenhouse. You can use water and regolith as mortar and the solar reflectors to dry it.
All of the water you used is contained inside your greenhouse. You won't lose any. You don't have to go out and get any more. Now, you start your plants.
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kbd512
Your robots would do everything to build sulfacrete homes on Mars before colonists land? I'm very okay with that, let's wait until that is possible.
Your tuna can will hold 12 people? I think ten is about the most I would attempt to cram in there and that is only if you can get the trip down to 30 days. Some things just should not be about profit.
The settlers will take a large vehicle to Mars and then land in a smaller vehicle? So the smaller lander vehicle would launch from the Earth and dock with the larger vehicle that always stays in orbit. But the larger vehicle would need more rocket fuel each time so how do you refuel it?
So, each time you have to launch a, smaller than a tuna can, Mars lander with 12 people, but you also have to launch another refueling vehicle to refuel the large transport.
So, in my scenario a tuna can can take 6 people and needs one launch. In your scenario a smaller tuna can takes 12 people in one launch but you have to launch a refueling mission so it takes two Earth launches.
It's the same, except mine doesn't need the large transfer vehicle in space. How many launches will it take for you to get all the parts for it into space and how do you assemble it? Spacebots?
I'm fixated on the tuna can? It's going to have everything already built and tested on the Earth before it leaves.
My tuna can would be a prison? Just like the Apollo capsule was a prison and the ISS is a prison and ships and submarines are prison. People who think that way shouldn't go. And your sulfur home would not be a prison?
The ability to construct more buildings is the ability to construct more greenhouses? Now you're on to the right track. I'm with that idea but I don't think sulfacrete would stand up in a humid environment.
You think the colony should be able to access all of it's infrastructure without leaving the pressurized environment? Now we're on the same page. You build a greenhouse, build bricks inside the greenhouse so you don't lose the water, then use those bricks to build a secondary habitat complex. It could be two stories, one under ground and one above ground, maybe one for apartments and one story would all be hydroponics.
If the ITS works then all of this stuff that you guys want to do becomes possible. Personally, even if it does fly I would just use it to build giant greenhouses.
Extra food comes from greenhouses built with sulfacrete? Sulfacrete is not transparent so the greenhouse foundation could be sulfacrete and perhaps a frame work could be sprayed and plastic windows installed.
But, here's the thing, if you have to send 100 plastic greenhouse windows from the Earth how is it better to spray a sulfacrete greenhouse frame to install the windows into when the window panels can be made to just fit together?
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That will work but it's only efficient if there is a large ice deposit at or very near your base so you can use an ATV and towed cart to bring large blocks inside the greenhouse.
The Mars Homestead guys chose a site in mid-latitude. One of the locations that Mars Reconnaissance Orbiter identified a glacier in the sides of the gully. That means right beside it. The location I keep talking about is the frozen pack ice in Elysium Planetia. That is: 800km (500 miles) by 900km (560 miles) and 45m (148 feet) deep. And I want to build right on the shore of this frozen ice. Not on the ice, on land, but right beside it. Visualize the distance from the front door of your house to the sidewalk in front of your house.
The Homestead Mars guys wanted to melt the ice deep down and keep and ice roof to contain the water vapor? Okay, the ice would melt and form a cavity full of water vapor but you still can't get the water vapor with a vacuum because you need the cavern to have some pressure in order for a vacuum to work.
And there won't be any water in that cave because there is no pressure.
...
Water doesn't exist on Mars except between the time of 33 to 35 degrees, that's about 6 minutes each day near the equator.
You appear to understand the facts, but keep ignoring them. Yes, the pressure on Mars is above the triple point. That means liquid water can and does exist on Mars. No, it's not vacuum. It's low pressure, but not vacuum. You just said there's a temperature range where liquid water can exist. In an enclosed ice cave, the pressure will be the same as Mars ambient, but the temperature will not. Temperature will be controlled. The idea is to maintain a pool of liquid water in that cave. To melt ice to create the cave, so the cave will enlarge as you harvest water. Keep it enclosed so vapour does not escape. And keep heat in, to maintain the correct temperature range for liquid water. Also the temperature range you cited is for clean water. What is it for salt water?
And specifically, the ice at Elysium Planetia. That's believed to have formed when a volcano melted permafrost. This is the bottom of the dried-up ocean basin. So the bottom of a dried-up ocean will have all the salt of the ocean, concentrated into remaining permafrost. Water evaporated to fall as snow at the south pole. Most of the water from that ancient northern ocean is now ice at the south pole. But water evaporates, salt does not. There are salt mines in the US and Canada beneath the Great Lakes; deposits from a time when there was a salt sea there. It completely dried up. Then an ice age covered it, and dug out the basins we know today. The lakes filled with fresh water when the ice sheet of the ice age melted. But the salt from the sea that existed before is still underground. There have been several ice ages and several interglacial cycles since, but the salt is still there. Europe has similar salt deposits beneath the Mediterranean. Millions of years ago the Mediterranean Sea completely dried up. All the salt became deposits on the floor. It got covered in silt and mud, protecting it. Then tectonic movement opened the Straights of Gibraltar, flooding the Mediterranean again. The floor of the Mediterranean immediately inside the Straights was scoured, but the rest of the Mediterranean still has the salt deposits. I expect similar salt deposits beneath the dried-up ocean basin on Mars. Again, the frozen pack ice was caused by a patch of permafrost melting, which would have that ocean salt. That melt water pooled in a low spot, then froze. So that should have highly concentrated salt. That should both lower the melting temperature, and raise the boiling point.
Pumping: The lowest pressure recorded by Curiosity was 690 Pa, which a pressure calculator says equals 7.036 cm of water @ +4°C. So that means a hose could suck water up to a height of 7cm above water surface. Then a pump could pressurize water in the hose, providing pressurized water to the habitat. So basically you need a pump right at the water inlet.
Or there's what I started with: cut blocks of ice. A news article talked about rescue of someone who fell into river ice. First Responders used a chain saw to cut blocks of ice. They didn't bother with a hot knife, they just used a chain saw. We could do that on Mars.
I don't like the idea of harvesting ice or attempting to get water on Mars.
So you want to stay on Earth.
Last edited by RobertDyck (2017-04-18 16:55:28)
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Is all ice the same? And what about ice mixed with regolith (probably the form it will appear in near the surface I would have thought...
I favour softening with microwave radiation. Or maybe we could insert a super-heated rod and then pump out the water.
Dook wrote:That will work but it's only efficient if there is a large ice deposit at or very near your base so you can use an ATV and towed cart to bring large blocks inside the greenhouse.
The Mars Homestead guys chose a site in mid-latitude. One of the locations that Mars Reconnaissance Orbiter identified a glacier in the sides of the gully. That means right beside it. The location I keep talking about is the frozen pack ice in Elysium Planetia. That is: 800km (500 miles) by 900km (560 miles) and 45m (148 feet) deep. And I want to build right on the shore of this frozen ice. Not on the ice, on land, but right beside it. Visualize the distance from the front door of your house to the sidewalk in front of your house.
Dook wrote:The Homestead Mars guys wanted to melt the ice deep down and keep and ice roof to contain the water vapor? Okay, the ice would melt and form a cavity full of water vapor but you still can't get the water vapor with a vacuum because you need the cavern to have some pressure in order for a vacuum to work.
And there won't be any water in that cave because there is no pressure.
...
Water doesn't exist on Mars except between the time of 33 to 35 degrees, that's about 6 minutes each day near the equator.You appear to understand the facts, but keep ignoring them. Yes, the pressure on Mars is above the triple point. That means liquid water can and does exist on Mars. No, it's not vacuum. It's low pressure, but not vacuum. You just said there's a temperature range where liquid water can exist. In an enclosed ice cave, the pressure will be the same as Mars ambient, but the temperature will not. Temperature will be controlled. The idea is to maintain a pool of liquid water in that cave. To melt ice to create the cave, so the cave will enlarge as you harvest water. Keep it enclosed so vapour does not escape. And keep heat in, to maintain the correct temperature range for liquid water. Also the temperature range you cited is for clean water. What is it for salt water?
And specifically, the ice at Elysium Planetia. That's believed to have formed when a volcano melted permafrost. This is the bottom of the dried-up ocean basin. So the bottom of a dried-up ocean will have all the salt of the ocean, concentrated into remaining permafrost. Water evaporated to fall as snow at the south pole. Most of the water from that ancient northern ocean is now ice at the south pole. But water evaporates, salt does not. There are salt mines in the US and Canada beneath the Great Lakes; deposits from a time when there was a salt sea there. It completely dried up. Then an ice age covered it, and dug out the basins we know today. The lakes filled with fresh water when the ice sheet of the ice age melted. But the salt from the sea that existed before is still underground. There have been several ice ages and several interglacial cycles since, but the salt is still there. Europe has similar salt deposits beneath the Mediterranean. Millions of years ago the Mediterranean Sea completely dried up. All the salt became deposits on the floor. It got covered in silt and mud, protecting it. Then tectonic movement opened the Straights of Gibraltar, flooding the Mediterranean again. The floor of the Mediterranean immediately inside the Straights was scoured, but the rest of the Mediterranean still has the salt deposits. I expect similar salt deposits beneath the dried-up ocean basin on Mars. Again, the frozen pack ice was caused by a patch of permafrost melting, which would have that ocean salt. That melt water pooled in a low spot, then froze. So that should have highly concentrated salt. That should both lower the melting temperature, and raise the boiling point.
Pumping: The lowest pressure recorded by Curiosity was 690 Pa, which a pressure calculator says equals 7.036 cm of water @ +4°C. So that means a hose could suck water up to a height of 7cm above water surface. Then a pump could pressurize water in the hose, providing pressurized water to the habitat. So basically you need a pump right at the water inlet.
Or there's what I started with: cut blocks of ice. I news article talked about rescue of someone who fell into river ice. First Responders used a chain saw to cut blocks of ice. They didn't bother with a hot knife, they just used a chain saw. We could do that on Mars.
Dook wrote:I don't like the idea of harvesting ice or attempting to get water on Mars.
So you want to stay on Earth.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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Moderator needs to remove spam from this thread!
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RobertDyck
Louis found an MIT study that says that 31 degrees off of the equator gets the most direct sunlight and Elysium Planitia is a bit below that. If you go higher in latitude above Elysium Planitia you hit the volcano's where there is much less water. Mars Odyssey shows that whole area of Elysium Planitia as having less water than Amazonis Planitia.
Salt water freezes at a much lower temperature than fresh water? It does depending on how much salt is in it. I think we would have to somehow observe this area before trying to put a settlement near it. If this place does have salty ice then it would become a sloshy lake each day.
That would be a source of salt water but impassable for rovers except when it's frozen.
I want to stay on the Earth? Yes, absolutely. Space travel is for the youngsters.
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Well, I argue for Elysium Planetia. My greenhouse design works better at lower latitude. That is long and narrow: exactly twice as wide as it is high, and much longer than it is wide. Oriented perfectly east-west, with a mirror along the full length of each side. If built perfectly on the equator, each mirror would be angled 45°. This would reflect sunlight at high noon at the spring or autumnal equinox perfectly into the sides of the greenhouse. The reason for twice as wide as high is this provides as much illumination from the mirrors as directly overhead. Total illumination is exactly equal. The mirrors will not track the Sun. At dawn sunlight will reflect westward, but will still be within the greenhouse. At dusk the mirrors will reflect eastward, but again still within the greenhouse. So the reason for a long-narrow greenhouse is the mirrors do not have to track. However, mirror angle will have to be adjusted for latitude, and will have to adjust for seasons. Based on Mars axial tilt and length of year, the angle will have to be adjusted 1° every 14 solar days (sols). That's such a slight adjustment that mirrors could be held by a notched rod. Someone in a spacesuit could adjust the mirrors to the next notch, once every second week. Again, this allows greenhouse operation with absolutely zero power. Or you could set it up with a motor that adjusts automatically once ever second week, with a backup option so someone in a spacesuit could do it manually.
This design becomes awkward at high latitude. At 31° latitude you have to angle one mirror 45+(31/2)=60.5° while the other side is angled 45-(31/2)=29.5°. Then adjust for axial tilt of 25.19°: at the winter solstice the north side mirror will be angled 45+(31/2)+(25.19/2)=73.095° while the south side mirror would be 45-(31/2)-(25.19/2)=16.905°. Getting the top of the south side mirror the same height above ground when it's angled that flat would require a very tall mirror. Trigonometry: if the greenhouse is 3 metres tall, then when the mirror is angled 16.905° the hypotenuse is 3m/Sin(16.905°) = 10.316876m.
Basic formulae for the northern hemisphere:
Northern mirror at winter solstice: 45°+(latitude/2)+(axial tilt/2)
Northern mirror at summer solstice: 45°+(latitude/2)-(axial tilt/2)
Southern mirror at winter solstice: 45°-(latitude/2)+(axial tilt/2)
Southern mirror at summer solstice: 45°-(latitude/2)-(axial tilt/2)
Height of the mirror: for each side take the lowest angle, mirror height = greenhouse height / Sin(angle)
The frozen pack ice in Elysium Planetia is 5° north latitude. It doesn't matter if the rest of Elysium is dry, the frozen sea is a lot of water.
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Is all ice the same? And what about ice mixed with regolith (probably the form it will appear in near the surface I would have thought...
No, it's not all the same. For the reasons I gave, the frozen pack ice of Elysium will be very salty. Ice of the south pole is packed snow covered in a thin skiff of wind-blown dirt. So it will be fresh water ice, like a glacier on Earth or Antarctica. Glaciers in the sides of canyons at mid-latitudes formed when rivers flowed during freezing temperatures. Cold enough for ice to form on the shore, but warm enough for the river to flow. It will be frozen river water. Frankly, I'm not sure of conditions to form that, but it should be frozen river water. Then there are glaciers in craters at high latitudes. Permafrost in the ground will be frozen mud. Difference conditions that formed the ice, different impurities.
I favour softening with microwave radiation. Or maybe we could insert a super-heated rod and then pump out the water.
Doesn't have to be super heated. Just an electric heating element in a rod to continuously provide heat; hot as a soldering iron or hot as an industrial hot-knife should be enough. Then you have issues Dook is obsessed about: boiling temperature of water at low pressure is quite close to freezing. If you use too much heat, how to you ensure you don't lose that water as escaping steam?
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RobertDyck
Shouldn't greenhouse plants get enough sunlight without the need for reflective mirrors?
You say that allows greenhouse operation without any power? Is there something that says that greenhouse plants won't get enough sun on Mars?
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Shouldn't greenhouse plants get enough sunlight without the need for reflective mirrors?
You say that allows greenhouse operation without any power? Is there something that says that greenhouse plants won't get enough sun on Mars?
Mean distance Sun to Earth: 149,600,000 km
Mean distance Sun to Mars: 227,940,000 km
Sunlight intensity is inverse square of distance, so...
(149,600,000)^2 / (227,940,000)^2 = 0.430746839 = 43.075% as much sunlight as Earth.
However, Mars has no ozone layer, and no clouds, so practically no filtration of sunlight and full bright sunny day all day every day.
UV would have to be filtered with spectrally selective coating on greenhouse windows that I already posted.
Some plants like shade, they will do well. However, plants that like full sun will want the additional light offered by mirrors.
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Plants don't usually need UV rays however, most of the radiation emanating from the Sun is in the visible light spectrum, if you block the UV, you aren't blocking all that much in proportion to what the Sun radiates. It might make sense to have pressurized greenhouses in the polar regions of Mars, the thin atmosphere doesn't carry away heat very efficiently, and you get 24 hours of sunlight for a number of months sufficient for growing many crops, and of course water is available here. If we wanted to grow food on Mars, we might want to consider the poles during summer. With 24-hours of sunlight, heating shouldn't be a problem.
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Dook wrote:Shouldn't greenhouse plants get enough sunlight without the need for reflective mirrors?
You say that allows greenhouse operation without any power? Is there something that says that greenhouse plants won't get enough sun on Mars?
Mean distance Sun to Earth: 149,600,000 km
Mean distance Sun to Mars: 227,940,000 km
Sunlight intensity is inverse square of distance, so...
(149,600,000)^2 / (227,940,000)^2 = 0.430746839 = 43.075% as much sunlight as Earth.
However, Mars has no ozone layer, and no clouds, so practically no filtration of sunlight and full bright sunny day all day every day.
UV would have to be filtered with spectrally selective coating on greenhouse windows that I already posted.
Some plants like shade, they will do well. However, plants that like full sun will want the additional light offered by mirrors.
Mars gets less sunlight than the Earth? Yeah, it does, but do you have something that says that vegetables, grains, berry plants, or fruit trees need Earth light levels?
Having mirrors outside the greenhouse is fine. I think we will need them for some things, shinging light inside on our solar cooker for one, boiling urine, and maybe boiling Mars water that has salt in it. I would just like to know what vegetable plants require more light than Mars provides.
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Plants don't usually need UV rays however, most of the radiation emanating from the Sun is in the visible light spectrum, if you block the UV, you aren't blocking all that much in proportion to what the Sun radiates. It might make sense to have pressurized greenhouses in the polar regions of Mars, the thin atmosphere doesn't carry away heat very efficiently, and you get 24 hours of sunlight for a number of months sufficient for growing many crops, and of course water is available here. If we wanted to grow food on Mars, we might want to consider the poles during summer. With 24-hours of sunlight, heating shouldn't be a problem.
We can't live at the poles. It's just too cold. Just because the pole might get 24 hours of sunlight at times doesn't mean they get warm. Alaska gets 24 hours of sunlight too at times but because it's so sparse, it's not direct rays, it doesn't provide nearly enough heat like the equator gets.
Any Mars settlement has to be located at or near 31 degrees off of the equator. That's where Mars gets the most direct sun.
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If there is adequate electric power to spare, use supplementary artificial lighting. Power not used is then power wasted, especially when people are sleeping.
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I would just like to know what vegetable plants require more light than Mars provides.
What Kind of Vegetables Like Full Sun to Grow?
There is a fruit or vegetable that can be grown in just about every garden spot. Tomatoes, cucumbers, peppers, peas, beans, corn and squash benefit from being grown in areas with full sun. Carrots, radishes, beets and other root vegetables require at least half a day of sun to thrive. Leafy greens such as spinach, chard, kale and the many varieties of lettuce tolerate the most shade in the garden.
How to Grow Wheat: Growing Wheat Organically
Both winter and spring wheat require full sun and prefer growing temperatures between 70 and 75 degrees F (21 to 24 C). Each should also be watered sparingly, as water can lead to numerous diseases.
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Your robots would do everything to build sulfacrete homes on Mars before colonists land? I'm very okay with that, let's wait until that is possible.
I want robots to collect water, robots to collect building materials, and robots to build bunkers. We already have robots that can do all of those things here on Earth. The actual robots that go to Mars will vary from what we use on Earth, for reasons pertaining to radiation exposure, temperature extremes, and weight. We won't send steel robots because steel is too heavy, but Aluminum or Titanium alloys will be used. The basic programming and communication will be very similar or the same. Fabrication of the robots is not that difficult, but the programming is more complicated.
The water collection robots employ a novel use of permanent magnets to create motion, but "ball balancing" robots that already use this locomotion are not terribly sophisticated, apart from the programming involved.
Your tuna can will hold 12 people? I think ten is about the most I would attempt to cram in there and that is only if you can get the trip down to 30 days. Some things just should not be about profit.
In the capitalist system everything is about profit, like it or not. The Bigelow Aerospace B330 can physically accommodate 12 people, so that's how many I'm sending. If I could stuff more people in the B330 to reduce cost, I would.
The settlers will take a large vehicle to Mars and then land in a smaller vehicle? So the smaller lander vehicle would launch from the Earth and dock with the larger vehicle that always stays in orbit. But the larger vehicle would need more rocket fuel each time so how do you refuel it?
The Cygnus lander vehicle takes colonists and supplies from Mars orbit to Mars surface. Cygnus is a very small can, but it was built to withstand 8g Max-Q aboard Orbital ATK's Antares rocket. We won't subject it to anywhere near that much force. It's cheap enough to be expendable for ISS resupply, but by sending new heat shields with the fusion driven rocket carrying the colonists, we don't have to throw it away after we pay SpaceX to ship it to Mars.
The larger vehicle, the fusion driven rocket with the B330 docked to it, has a delta-V capability so high that it can go to Mars and come back to Earth prior to refueling. As such, it'll refuel at ISS. Delivering a B330 to LMO and attaching a second B330 to ISS would make the launch schedule more flexible, but it's not required.
The loaded B330 will be about half the weight of the original payload that the fusion driven rocket was supposed to deliver to Mars. Substantially less fuel is required as a result. When the B330 is returned by the fusion driven rocket to Earth, with nobody aboard, it's about 31t lighter than when it left Earth. The subsequent Falcon Heavy launches only deliver colonists / cargo / fusion rocket fuel to LEO. Since no upper stages get sent to Mars, the potential exists to recover the entire rocket. SpaceX is currently working on upper stage recovery.
So, each time you have to launch a, smaller than a tuna can, Mars lander with 12 people, but you also have to launch another refueling vehicle to refuel the large transport.
The colonists and their Lithium fuel to get their fusion driven rocket to Mars ship in the same Falcon Heavy launch. It's 35t of fuel, 6t of consumables, and 2t of colonists and personal articles. Falcon Heavy can deliver 68t (Edit 63.8t, not 68t) to LEO since it's been up-rated by SpaceX with full-thrust engines. Any remaining payload capacity will be repair parts for the fusion rocket or consumables for ISS crew. A reconfigured Dragon V2 capsule will carry the colonists and fuel to ISS where the ISS crew will refuel the fusion rocket by replacing the Lithium fuel cannisters.
So, in my scenario a tuna can can take 6 people and needs one launch. In your scenario a smaller tuna can takes 12 people in one launch but you have to launch a refueling mission so it takes two Earth launches.
In my Scenario a volumetrically larger tuna can takes 12 people to Mars in 30 to 90 days instead of 180 days. Then a much smaller tuna can docks with the larger tuna to take the colonists from Mars orbit to Mars surface. The smaller tuna can never leaves Mars except to pick up colonists and cargo from Mars orbit. The small tuna can is either fetching colonists and cargo or it's in a repair facility at the bunker on Mars.
It's the same, except mine doesn't need the large transfer vehicle in space. How many launches will it take for you to get all the parts for it into space and how do you assemble it? Spacebots? I'm fixated on the tuna can? It's going to have everything already built and tested on the Earth before it leaves.
The larger transfer vehicle I proposed using only has a larger B330 habitat attached to it. In terms of overall tonnage, it's 80t. Two Falcon Heavy launches are initially required to get the fusion driven rocket into Earth orbit (one for the B330 and one for the fully fueled fusion rocket). Thereafter, one Falcon Heavy launch is required to refuel the fusion rocket in Earth orbit and bring a dozen new colonists after the fusion rocket returns (empty) from its last trip to Mars.
Your tuna can requires SLS to send it to Mars since you're trying to go from the surface of the Earth to the surface of Mars in the same vehicle. If Falcon Heavy is never reused, which won't happen, then I still get 5 Falcon Heavy rockets for the cost of one SLS rocket that can deliver a Mars Direct tuna can to Mars.
The difference is that this vehicle stays in space after it's launched and never reenters at Mars. I don't have to get an 8.4m diameter and 11.1m tall tuna can to the surface, just a 3.07m diameter and 5.1m tall tuna can. My reusable tuna can stays on Mars until it's sent to orbit Mars using its reusable mini-booster and it weighs around 2t when it launches from the surface of Mars to pick up the colonists.
Falcon Heavy - 63t to LEO, $100M per launch (no reuse) (Edit: 63.8t, not 68t)
SLS Block IIB Cargo - 125t to LEO, $500M per launch (no reuse)
My tuna can would be a prison? Just like the Apollo capsule was a prison and the ISS is a prison and ships and submarines are prison. People who think that way shouldn't go. And your sulfur home would not be a prison?
I said my sulfur home would have the layout of a prison. The common area in the center is for the cafeteria, showers, laundry, lounge, and exercise room so as to minimize piping required. The cells surrounding the common area are for the colonists, thus my comment that my bunker layout looks like a prison. There's just enough room to lay down or sit at a desk printed into the side of the cell to use an iPad or laptop for study. Shelves printed into the wall will store clothing. You'll have about as much personal space as a lower ranking officer aboard a submarine. Your room light has a battery (no wiring) and your pad or computer uses a power brick (no wiring). Every room has an airlock actuated with polymagnets (no wiring or hydraulics, just permanent magnets and a special type of diaphragm that seals when you change the pressure too fast). Polymagnets is a brand of permanent magnets that attracts and repels at the same time until you breach a threshold distance, after which the magnets attract each other. Unlike regular permanent magnets, their "hold" is much more powerful. Google it.
Fire is bad news for sulfacrete since it will melt. It's re-castable, so if you make a mistake you can fix it later by adding heat and the strength of the re-cast sulfacrete increases, sort of like work-hardening metal. You add a little more heat to re-soften it, just like annealing metal. That is why piping and wiring are minimized and every room has a mechanical diaphragm airlock.
The ability to construct more buildings is the ability to construct more greenhouses? Now you're on to the right track. I'm with that idea but I don't think sulfacrete would stand up in a humid environment.
The greenhouse is physically connected to the "prison" (shares a common wall) and airlock (embedded in the wall). It's the same building with different rooms. Nobody is getting their own home, as a function of safety and cost. You can think whatever you want about sulfacrete absorbing water, but physics won't change to suit your personal beliefs. Sulfacrete has the mechanical properties that it has. You could throw out an objection about it melting if there is a fire, because it will do that if there is a fire and the fire doesn't have to be very hot, but it will not absorb water.
You think the colony should be able to access all of it's infrastructure without leaving the pressurized environment? Now we're on the same page. You build a greenhouse, build bricks inside the greenhouse so you don't lose the water, then use those bricks to build a secondary habitat complex. It could be two stories, one under ground and one above ground, maybe one for apartments and one story would all be hydroponics.
Delivering cement trucks to Mars isn't cheap or easy, so I have a mandate to maximize the utility of every kilogram of Sulfur collected.
Within reason, I want to maximize efficiency and minimize costs. I won't skimp on life support, water, or rations. Every critical system must be triple-redundant. Weekly consumables inventories will be performed to assure that the colonists are always aware of how much they have of what they need. This information will be shared with everyone at weekly status report meetings and there will be no secrets. A 24/7 environmental controls watch and rescue team will be staffed. Every colonist will learn to operate the life support systems and conduct emergency action drills.
If the ITS works then all of this stuff that you guys want to do becomes possible. Personally, even if it does fly I would just use it to build giant greenhouses.
ITS should be a two-stage 350t to LEO fully reusable rocket and nothing more. The fusion rockets and reusable landers will be the most economical means of transporting people to Mars, as a function of launch costs, propellant costs, and maintenance costs. ITS could deliver a small fleet of fusion rockets to LEO. Thereafter, ITS would be a cargo and propellant tanker. ITS is the AN-225 of rockets. We use SLS and ITS when nothing else can provide the raw power required.
Extra food comes from greenhouses built with sulfacrete? Sulfacrete is not transparent so the greenhouse foundation could be sulfacrete and perhaps a frame work could be sprayed and plastic windows installed.
The greenhouses will use fresnel lens skylights sent from Earth. There will be no frames or transparent paneling, just fresnel lenses embedded in a sulfacrete roof at regular intervals. A fresnel lens weighs a fraction of what a complete set of transparent panels would weigh and since there is so much material in the walls of the greenhouse, it is better insulated than a greenhouse constructed with light weight transparent panels, unless the panels are thick, and thus heavy, or have an inert gas trapped inside, which would also make the panels heavy. The entire colony, to include the greenhouses, will be pressurized to 14.7psi and keep at least 1 meter of material between the colonists and the surface radiation environment.
But, here's the thing, if you have to send 100 plastic greenhouse windows from the Earth how is it better to spray a sulfacrete greenhouse frame to install the windows into when the window panels can be made to just fit together?
The fresnel lenses will be embedded into the sulfacrete when the colony is 3D printed. If they need to be replaced or the sulfacrete needs to be re-cast, the greenhouse will be emptied and the robots will re-heat and re-cast the sulfacrete as necessary.
Last edited by kbd512 (2017-04-18 23:19:54)
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kbd512
We have robots that collect water, collect building materials, and build bunkers on the Earth? Where?
It sounds like you've never used titanium before. It's not lightweight at all. It's stronger by weight than steel but that doesn't mean it's lightweight compared to aluminum or composites.
In the capitalist system everything is about profit? What profit is there in education? What profit does the government provide the people? What profit is there in environmental protection? What profit is there in having a military? What profit is there in having welfare, social services, police, water, sewage, trash collection, legal, and fire departments?
The Bigelow B330 can take 12 people? What does it use as radiation shielding?
Your large transport will refuel at the ISS? The ISS doesn't have refueling tanks, so you're talking about even more launches to modify the ISS. How can these ideas be more profitable when it requires more launches than a Mars Direct type of mission would?
The potential exists to recover the entire rocket? Except the Cygnus and it's fusion rocket stays on Mars?
The small Mars ascent vehicle, how does it get refueled, a new heat shield, and new parachutes after each flight?
Is the large transport performing an aero-capture at Mars and then again at the Earth? What heat shield can withstand two aero-captures? How do you put a new heat shield on it at the Earth?
You get 5 Falcon Heavy rockets for the cost of one SLS rocket? SpaceX can probably do things cheaper than NASA, I'm not arguing that. Cheaper isn't always better.
Your sulfacrete complex has a cafeteria? A what, a cafeteria at a Mars settlement?
Shelves printed into the wall? You mean sprayed.
The sulfacrete sounds interesting. I don't really have a problem with using it if there was an easier way to obtain and separate the sulfur and right size aggregate. There's just no way it's going to be reasonable for any early settlement.
How does a 3D printer spray an entire greenhouse? You would have to let is spray one small section, then move it, let it spray again, then move it, over and over and over again all the way around. Then you would have to raise it up ten feet or so and do it all over again for the next row. Why not just spray it yourself with an insulated hand sprayer?
Last edited by Dook (2017-04-19 00:47:44)
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We have robots that collect water, collect building materials, and build bunkers on the Earth? Where?
Is your Google broke?
It sounds like you've never used titanium before. It's not lightweight at all. It's stronger by weight than steel but that doesn't mean it's lightweight compared to aluminum or composites.
It's light enough to do the job, resists corrosion, and there are companies that routinely make Titanium fuel tanks for rockets. The water tanks would just operate at much lower pressures than propellant tanks. I'm not trying to make the robots weightless, I'm trying to make them durable enough to last a long time and light enough to affordably ship. Whether we could spend tens of millions more to use some exotic lightweight composite or whatnot is irrelevant if the total weight of the robot is well within what we can launch to Mars right now.
In the capitalist system everything is about profit? What profit is there in education? What profit does the government provide the people? What profit is there in environmental protection? What profit is there in having a military? What profit is there in having welfare, social services, police, water, sewage, trash collection, legal, and fire departments?
What profit is there in education? Did you ever go to college? You can't be serious.
I pay a co-op for water and a company for electricity. I pay another private company for trash collection.
Social services are socialism, the opposite of capitalism. In this country we have the Democrats (Socialists) and Republicans (National Socialists). Either way, you're getting some of that socialism mixed in with your capitalism.
Our government provides oppressive taxation, fear mongering for the masses of uneducated and unthinking lemmings, and endless wars. Maybe you live in your own little country, but if you live in the US of A like I do, then you'd know our government is all about that almighty dollar and sees nothing wrong with robbing Paul to pay Peter or killing Paul to pay Peter. On the bright side, you know what they want. They don't care about you, they just want your money.
The Bigelow B330 can take 12 people? What does it use as radiation shielding?
Hydrogen rich fabrics and elastomers. The walls are about 18" thick when it's inflated. It still has to use a water tank as a solar flare shelter.
Your large transport will refuel at the ISS? The ISS doesn't have refueling tanks, so you're talking about even more launches to modify the ISS. How can these ideas be more profitable when it requires more launches than a Mars Direct type of mission would?
I already said the refueling tanks are coming from Earth with the colonists on the same Falcon Heavy. Are you getting your colonists from somewhere other than Earth, or do you need to launch another rocket every time you want to send more people, too?
The potential exists to recover the entire rocket? Except the Cygnus and it's fusion rocket stays on Mars?
The potential to recover the entire Falcon Heavy rocket. Cygnus stays on Mars. The fusion rocket stays in space.
The small Mars ascent vehicle, how does it get refueled, a new heat shield, and new parachutes after each flight
The ascent vehicle is refueled on Mars using LOX and water to make LOX/LCH4. The fusion rocket brings the heat shield for the next Cygnus flight from Earth with the next group of colonists. No parachutes are used. Cygnus uses HIAD and rocket engines to soft land on Mars.
Is the large transport performing an aero-capture at Mars and then again at the Earth? What heat shield can withstand two aero-captures? How do you put a new heat shield on it at the Earth?
The large transport doesn't do aero-capture. The specific impulse and thrust of the fusion driven rocket is so high that it propulsively captures into orbit on both ends.
You get 5 Falcon Heavy rockets for the cost of one SLS rocket? SpaceX can probably do things cheaper than NASA, I'm not arguing that. Cheaper isn't always better.
ULA and Blue Origin are following SpaceX's lead. ULA will produce Vulcan Heavy and Blue Origin will produce New Glenn. If you include Falcon Heavy, we'll have three different heavy lift vehicles to choose from and real competition to lower prices.
Your sulfacrete complex has a cafeteria? A what, a cafeteria at a Mars settlement?
How else would you feed dozens of people? Do you need your own personal chef?
Shelves printed into the wall? You mean sprayed.
Printed, sprayed, whatever. I want sulfacrete shelves to store articles of clothing, linens, spare parts in work areas, food in the cafeteria. There won't be any furniture and cabinets that have to be brought from Earth because that costs too much.
The sulfacrete sounds interesting. I don't really have a problem with using it if there was an easier way to obtain and separate the sulfur and right size aggregate. There's just no way it's going to be reasonable for any early settlement.
Sifting sand is too much work?
How does a 3D printer spray an entire greenhouse? You would have to let is spray one small section, then move it, let it spray again, then move it, over and over and over again all the way around. Then you would have to raise it up ten feet or so and do it all over again for the next row. Why not just spray it yourself with an insulated hand sprayer?
Have you ever sprayed concrete 1 yard thick, as high as your head, by hand? If so, then we'll make you the official concrete hand sprayer for this mission.
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There are other options for shelves. We could simply cut, using stone saws, layers of basalt ,and polish them up.
https://www.youtube.com/watch?v=8CqJGJYobUs
Here's a large scale version of the process.
You can make basins as well - useful for industrial processes.
Let's Go to Mars...Google on: Fast Track to Mars blogspot.com
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kbd512
I didn't find any water collecting robots. Found some articles about how one day we might have robots do those things. I also didn't find anything on robots replacing loggers or processing cement or asphalt or steel or aluminum.
Titanium is light enough to do the job? If you want to build jet engines or super thin fuel tanks for spacecraft then yes, other than that it's way too expensive and not preferred over aluminum or composite. If you want them to have some weight because they need to move heavy material then just use steel. Metals won't corrode on Mars, you need oxygen for that to happen.
What profit is there in education? Education is an expense for a capitalist system. The system pays for 12 years of education and some of the people end up in jail (more expense to the system), being housewives, and under employed while others work hard and pay for the less talented and lazy.
Did I go to college? Yes, five years, GPA was 3.72, what was yours?
You pay for water and trash service? But that is not profit to the capitalist system. Those utilities receive the amount of money needed to provide the service. It balances out, there is no excess money going to the government. There is no "profit".
I'm getting some Socialism mixed in with my Capitalism? Yeah, I am, but that's what modern Capitalism is. There is no pure socialism and no pure capitalism other than in the textbooks.
The Bigelow has 18" thick walls for shielding? Can't be 18 inches of solid fabric, has to be an air cavity with an outer layer of fabric and an inner layer. That's not shielding.
Your colonists launch on a Falcon Heavy that also has fuel for the large transport? Okay, so the Falcon Heavy docks with the ISS, offloads 12 people who go over to the large transport, the Falcon refuels the large transport, transfers a heat shield to it, then the Falcon comes back to the Earth and the transport goes to Mars?
If the transport is getting to Mars in 30 days it's really moving, it would use a great deal of fuel to accelerate and slow down.
The Cygnus would fly from Mars up to the transport, the colonists would somehow install a new heat shield onto it, then land?
There is way, way, too much risk in this idea.
We'll soon have three different lift vehicles in competition? Sounds like NASA could contract SpaceX to use it's Falcon Heavy to send it's Zubrin tuna can's to Mars.
You need a cafeteria to feed dozens of people? Yeah, in about 500 years from now. Or, the 4 first settlers could grab a food packet, add a little water, toss it into the microwave on their own. See, no cafeteria needed.
You want sulfacrete shelves? Or we could just send fiberglass shelves and fiberglass panels that can be assembled into cabinets, drawers, and picnic tables.
Sifting sand is too much work? Nothing is too much work if it needs to be done. If it doesn't need to be done, then that becomes a problem.
You're creating work just to create work. It's inefficient and not a single part of it adds any food, water, or oxygen. Just habitat, oh, and a cafeteria.
Have I ever sprayed concrete 1 yard thick? No, I have people do that for me. They poured concrete about a foot thick for my home foundation. It took them a couple of hours to set up the posts and framing and about an hour to actually walk around pouring in the cement.
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All of you want to harvest ice for water on Mars so you want to land in areas that have a great deal of ice. If that ice has a lot of salt in it the ice would be liquid for longer periods of each day than pure water/ice would. This would create a slushy surface that would be dangerous to land on and impassible for walking and rovers except when it was frozen.
NASA can't land accurately enough to get close to one of these areas. The Red Dragon supposedly has a 6.2 mile landing accuracy. Attempting to land next to a source of water would be too dangerous.
So, to get water or ice, a rover will probably have to drive some distance away from the base.
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Different salts have different effects on freezing point depression. NaCl/ice mix freezes a bit below -20C. CaCl/ice mix will go a lot colder than that. I don't know about mixed salts with ice. As more ice melts and dilutes the salts the freezing point reduction is lessened so it is self limiting.
On refreezing, the ice expels the salt until a very low temperature is reached when the now saturated brine can itself freeze.
The seasonal appearance of gullies and dark marks indicates either that what you propose is indeed happening or that salts are being hydrated by attracting moisture from vapour.
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Land an unmanned rover first to confirm the water resource. That rover could land a significant distance away, and drive to the ice. Just as Spirit/Opportunity or Curiosity does. In this case the rover would be about the size of Spirit/Opportunity, with a multi-segment drill to take core samples. That same rover could drop a landing beacon. With a beacon, the manned mission could land with precision. Imagine if Curiosity landed with it's aeroshell/parachute/skycrane, but it's skycrane homed in on the beacon. Also remember the aeroshell had the ability to steer. I argue for landing rockets on the lander, and legs with shock absorbers. So it would land like the Apollo LM. But instead of a single large engine, it would have several smaller ones. Viking landers and Mars Phoenix had several smaller engines, and the Curiosity skycrane. Several smaller engines means exhaust impact on soil during landing is spread out, so less chance of digging yourself a hole. And several small engines can be arranged around the periphery, so a Mars rover can be stored in the centre of the lower deck of the lander. But again, homing on a beacon means high precision landing.
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