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In the initial years, meteorites and regolith from Mars will be subject to huge demand. There are at least 20,000 universities and other higher education institutes in the world. Let's assume that there are 15,000 with departments such as geology, astronomy, materials, etc who would be interested in acquiring such material. If over ten years, let's say, they are each prepared to spend $100,000 on average, that's $1.5 billion revenue. Some v. prestigious institutions (Harvard, Yale, Oxford, Paris, etc) will be prepared to pay much more than that average - probably $100millions over a decade.
If fossils are found there will be a similar "gold rush" among biology and genetics departments.
Of course to the universities you have to add multi-national companies, private individuals (collectors), defence agencies and others who may have their own reasons for acquiring Mars meteorites or regolith. You can probably add another billion or so for them.
I ran the numbers for a 50m diamter dome, made from medium density polyethlene (yield strength 12MPa) and safety factor 5 (12.5cm thick). Inside temperature = 15C, outside temperature =-60C. This is the average temperature at a latitude 60N on Mars, the same latitude as Helsinki on Earth.
Initial results were a radiation and convection heat loss of 60W/m2 of dome, or 120W/m2 of internal floor. For conduction, I assumed a constant ground temperature of -20C at 1m depth and a thermal conductivity of 1W/mK for wet clay-like soil. Conduction heat losses are then 35W/m2 of floor.
Some of the results seem suspect to me, so i am going to double check. The blackbody heat loss at a temperature of 288K (15C) and background 213K (-60C) is 219W/m2 of dome surface, which would be 437W/m2 of floor. But we would expect some insulation from the dome itself.
Thanks for the help with that!
I went on a calculator site that gave me 1963 sq m for a 50m diameter circle. Multiplying 1963 by your 437 watts I get 857831 watts or about 858 Kws. Seems a lot but then a 50metre diameter dome is pretty big.
Although no doubt the figures don't translate, for a cubic hab of 4metres length, that would be a mere 7Kws approx., well within the capability of a PV panel and storage battery system.
And couldn't that be lowered through use of aerogel?
louis wrote:Hi Antius - are you able to help me out on this...if we had a say a cube hab measuring 4x4x4 metres with standard areogel insulation, and we had say three people inside on average per sol eating an average diet and maybe various bit of machinery using 240KwH per sol, pumping out waste heat , how much energy would we need to put in per sol to maintain the interior air temperature at say 20 degrees celsius (assuming ordinary earth atmosphere pressure) i.e. how much energy would we have to put in to counter heat loss? Or indeed might it be a case we had to cool down the interior - constantly or at certain times (e.g. during the day in high summer on Mars).
I'm afraid it's beyond me to work that out from your figures...but this seems to be the nub of the issue for me (as a proponent of enclosed farm habs).
Hello Louis, I will look into this. Might take a bit of time, as I'll need to set up a spreadsheet.
Thanks Antius, if you can spare the time to do the calculations that would be most useful.
A permanent Mars settlement will have an issue with toilet paper. There aren't any trees. Do we need a large greenhouse just to grow trees for TP? A simpler solution is a washlet. That's a special seat on a normal toilet. The seat is a bidet. So you wash your bottom after doing your business. Not in a separate bidet, but just the same toilet. More expensive models of washlet have an electric warmer for the water, and a warm air blower that works like a hand dryer in a public washroom. So you clean and dry your bottom before getting off the toilet. And use nothing but water, air, and electricity.
The washlet was invented in Tokyo, where most homes aren't connected to a city sewer. Each home has a septic tank, which gets clogged quickly by TP. Urban septic tanks are drained by a "honey wagon" (English term), a truck with a tank to collect sewage and a hose to suck it up. Using TP means the honey wagon has to come several times more often. That service charges for each pickup. So the washlet is just practical for Tokyo. It would be practical for Mars as well.
However, that raises another point. The "BioMars" group studied a grey water sewage treatment system. Terry Kok led an effort called the Green CELSS Taskforce; his effort was based on a composting toilet. So water, or no water? Both groups endeavoured to produce fertilizer for food crops.
Perhaps we can create a hi-tech equivalent of the Roman sponge stick.
Tom Kalbfus wrote:RobertDyck wrote:Actually, no. The equipment to make aerogel is quite involved. A science mission to Mars will bring an inflatable greenhouse, not anything solid like aerogel. And it will be a while before anyone on Mars will be able to make it. Expect the first greenhouse made with in-situ resources will be simple glass.
I said aerogel for a greenhouse on Earth. The website linked talks about growing food year-round. That means winter. I live in Winnipeg, Canada. We actually have winter. Your profile says you live in UK. Not sure which part, but weather statistics for London show average daily low for December, January, and February as 1°C, 0°C and 1°C. The same statistic for my city is -17.8, -19.6, and -11.6°C. In fact the average daily high for my city for January is -11°C. That's average, we can get a cold snap when it doesn't get above -20°C for a week. This year there were 90 days below -20°C, the most in 121 years. And that's the daytime high. This March one night it got down to -37°C. The coldest was -45°C one night in February 1966. And these are real temperatures, not wind chill.
Most older houses have double pane windows. Newer houses have sealed casement windows with plastic film stretched between the two glass panes, effectively creating a third pane. Some have 3 sheets of plastic, creating a total of 5 panes. It's to reduce heating cost. A greenhouse will have entire roof and walls of window. They'll need good thermal insulation. That's why I recommend aerogel for roof-top greenhouses on Earth.
The difference between Mars and Earth is that Mars has a laboratory vacuum for an atmosphere. The reason Earth greenhouses need insulation is because Earth's thick atmosphere absorbs heat from the greenhouse, the warmer air rises and is replaced with cooler air that absorbs more heat. On Mars the thin atmosphere can't do that very well. The heat radiates outward but the atmosphere doesn't convect the heat away like it does on Earth. Most of the insulation required for a Mars suit is the padding on the soles of an astronaut's boots and the surface of gloves that will be handling various rocks and samples. What you don't want to do is get buried in an Martian avalanche, because if you don't get crushed, you will quickly freeze as the ground absorbs your body heat!
I did a few heat transfer calculations to help answer this question.
I will calculate convective heat loss from a cylinder approximately at 30cm wide, 2m tall with a temperature of 36C in the Martian atmosphere. Wind speed = 10mph (4.5m/s). Density of Martian CO2 at -50°C and 0.81KPa is 0.44mol/m3 or 0.02kg/m3. Dynamic Viscosity is ~1x10-5pa.s. On this basis, the Reynolds number is:
Re=ρvL/μ
L is characteristic length, which is equal to 4 times cross-sectional area, divided by perimeter or 0.15m in this case. Reynolds is therefore 0.02x4.5x0.15/0.00001 = 1350.
Using the cylindrical cross-flow equation, Nusselt number can be calculated:
Nu = 0.193Re^0.618 x Pr^0.33
Prandtl, Pr=Cp.μ/k.
For CO2 under these conditions, k is 0.01W/m.K and Cp at 220K is 1960J/KgK. So Prandtl is 1.96. On this basis, Nusselt can be calculated to be 20.8.
The heat transfer coefficient, h= Nu.k/L. Which works out to be 1.4W/m2K.For a cyclindrical body with a surface area of ~1m2 and a temperature difference of 86K with the environment, heat loss rate can be calculated using Newton’s Law of Cooling:
Q=hA(T1-T2) = 1.4 x 1 x 86 = 120watts.
By contrast, radiation would lose 400watts of heat from the same body under the same conditions. So on the Martian surface, heat loss will be dominated by radiation and conduction. As a rough rule of thumb ‘the convection heat losses in the Martian atmosphere for any structure at room temperature, will be about 30% of the black body radiation heat loss rate’.
In a dust storm, with air velocity of 20m/s, the convective heat transfer coefficient increases roughly 2.5 times and thus reaches 75% of the black body radiation heat loss.
Hi Antius - are you able to help me out on this...if we had a say a cube hab measuring 4x4x4 metres with standard areogel insulation, and we had say three people inside on average per sol eating an average diet and maybe various bit of machinery using 240KwH per sol, pumping out waste heat , how much energy would we need to put in per sol to maintain the interior air temperature at say 20 degrees celsius (assuming ordinary earth atmosphere pressure) i.e. how much energy would we have to put in to counter heat loss? Or indeed might it be a case we had to cool down the interior - constantly or at certain times (e.g. during the day in high summer on Mars).
I'm afraid it's beyond me to work that out from your figures...but this seems to be the nub of the issue for me (as a proponent of enclosed farm habs).
For the farm hab, I favour (following in part Zubrin) "Roman brick" arch construction over trenches. The trenches can be cut out of the Mars regolith by small imported diggers (specially adapted or built of course for Mars conditions e.g. with microwave heaters to soften the regolith and make it easier to dig and powered by cable from solar panels). The bricks will be Mars bricks, manufactured automatically in special Mars kilns imported from Earth. These will convert the right recipe of Mars regolith and water into mud bricks which can be fired. The arches can be sealed with ice and covered with regolith. These semi-subterranean farm habs would be lit with LED lights, imported from Earth, and heated by warmed air - both powered by PV panels.
These structures will be quick to construct, and low maintenance.
The shelving for the mostly hydroponic agriculture could be manufactured locally, as steel parts.
The main issue will be air locks and ventilation.
I've wondered in the past about "ice doors" to replace imported air locks. The idea would be to have something like the equivalent of a U Bend that, when the lock is closed has ice at the bottom of the bend, but when you want to pass through, the ice is melted and the water is pumped out. When you want to close it again, you pump the water back in and refreeze it. Just an idea...since manufacturing air locks on Mars will be a resources heavy undertaking. Alternatively, could we use somethign like basalt to construct big roll over discs that seal locks and are kept in place by pressure difference.
If you want a small animal, pre-Columbian Inca people ate guinea pig. Rich members of that society ate llama and alpaca, but common folk at guinea pig. Their natural diet is grass, with a little fruits and vegetables. They're rodents, but don't naturally hibernate. But since they are rodents, would they respond to hydrogen sulphide the same way as mice or rats? Worth a try.
South Americans still eat them today. The ones used in farming are larger than the pet variety. I have argued before that they would be perfect for the first farmed animals on Mars, much easier to manage I think than chickens. I think they can survive well on green lettuce - at least our pet GPs did! Lettuce is just the sort of crop which should be easy to grow hydroponically.
Yet another major triumph for Space X...
My input is that the interplanetary economy can include terraforming efforts, say the sulfur and CO2 removal from Venus can be exported to Mars for agriculture as sulfur and carbon content. A very wild imagination is that the silicon after exploitation of ores on Mars, near earth objects or asteroids, meteorites etc. can be split into nitrogen by nuclear reaction.
1 mole of Si28 + huge energy input from nuclear fusion or fission ---> 2 moles of N14.
I wouldn't dismiss such considerations, but I would point out that currently in the solar system the grounded inhabitants of planet Earth account for about 99.999999999% of wealth in the solar system (the ISS accounting for the most part for the remainder), so it is likely to be there that a nascent Mars community will find the reciprocal trade economy that will ensure its survival.
RobertDyck wrote:louis wrote:I agree aerogel would be used to insulate indoor farm habs on Mars. But in terms of growing a self-sufficient economy on Mars, the colonists could make rockwool from basalt as insulation and simple reflectors could help maintain temperatures during the day or through heated water pools beneath the habs.
Actually, no. The equipment to make aerogel is quite involved. A science mission to Mars will bring an inflatable greenhouse, not anything solid like aerogel. And it will be a while before anyone on Mars will be able to make it. Expect the first greenhouse made with in-situ resources will be simple glass.
I said aerogel for a greenhouse on Earth. The website linked talks about growing food year-round. That means winter. I live in Winnipeg, Canada. We actually have winter. Your profile says you live in UK. Not sure which part, but weather statistics for London show average daily low for December, January, and February as 1°C, 0°C and 1°C. The same statistic for my city is -17.8, -19.6, and -11.6°C. In fact the average daily high for my city for January is -11°C. That's average, we can get a cold snap when it doesn't get above -20°C for a week. This year there were 90 days below -20°C, the most in 121 years. And that's the daytime high. This March one night it got down to -37°C. The coldest was -45°C one night in February 1966. And these are real temperatures, not wind chill.
Most older houses have double pane windows. Newer houses have sealed casement windows with plastic film stretched between the two glass panes, effectively creating a third pane. Some have 3 sheets of plastic, creating a total of 5 panes. It's to reduce heating cost. A greenhouse will have entire roof and walls of window. They'll need good thermal insulation. That's why I recommend aerogel for roof-top greenhouses on Earth.
The difference between Mars and Earth is that Mars has a laboratory vacuum for an atmosphere. The reason Earth greenhouses need insulation is because Earth's thick atmosphere absorbs heat from the greenhouse, the warmer air rises and is replaced with cooler air that absorbs more heat. On Mars the thin atmosphere can't do that very well. The heat radiates outward but the atmosphere doesn't convect the heat away like it does on Earth. Most of the insulation required for a Mars suit is the padding on the soles of an astronaut's boots and the surface of gloves that will be handling various rocks and samples. What you don't want to do is get buried in an Martian avalanche, because if you don't get crushed, you will quickly freeze as the ground absorbs your body heat!
Interesting observation. I am not disputing this with you, but would be interested if you could give a citation.
I suppose your argument would be that as long as you heat your Mars greenhouse, you don't have to worry too much about insulation. Which I take to be good news!
My suggestion:
I think you could release a lot of gases and increase heat retention by building lots of vehicles on Mars that go around doing this all day/sol, using concentrated solar energy.
So the challenge would be to find the most effective, and easily produced, sort of solar-powered vehicle that could go around the planet doing this job of heating up regolith and releasing gases.
There are more than a billion vehicles on Earth now. I suppose I am thinking on that sort of scale - billions of vehicles processing hundreds of billions of kgs of regolith every day. These vehicles would obviously be much simpler to produce than passenger vehicles on Earth with all their complex requirements.
I am thinking of this as almost a robotised process: robots scouring the planet for iron ore, making steel, producing the simple robot vehicles...and other robots producing PV panels from the silicon (silica?) and reflectors from polished steel or similar.
Any thoughts?
Dear Louis:
I didn't see you had posted until now; I apologize for the delay in responding. I don't think Musk is trickling out his plan in drips and drabs. I don't think he has all the details of his plan yet. He doesn't need to decide now what he will land on Mars because he still doesn't know whether he will build the Mars Colonial Transporter, whether he needs a triple barrel "heavy" version or not, whether he can land and reuse stages, etc. A lot of the plan hangs on the technology he is developing now and, even more importantly, what it will do in terms of profit. It appears Musk can develop a first stage that can land and be reused. But he still can't build a rocket that can be launched on time! The OS2 launch was supposed to go up in May and still hasn't gone up. He's supposed to launch about 10 to 12 Falcons this year, but he can't get them up.
He is aware of the problem, of course. Musk made the comment that his company needs to go from ten launches per year to hundreds, then to thousands. But no one knows how to do that, and that's a much harder technological problem to solve.
As for my "gryphon," the key idea is that if you can develop a spacecraft that in one variant can take tourists to orbit, another variant will take astronauts to the moon, and a third variant will take astronauts to Mars, you can amortize your development costs over a much larger number of flights, and that is important. That's basically what the Falcon series of rockets do, as well; anything that goes to Mars will be launched on a rocket that will have already been uses dozens or hundreds of times.
I agree with your basic "gryphon" concept (i.e. spreading costs between different uses). I tend to see it in terms of orbital assembly. If you want to go to Mars you have to assemble a number of parts - the propulsion system, the lander/ascent vehicle, the supply module and the hab. It's certainly within current capabilities. And each of the part may have other uses.
I assume Space X problems with throughput of launches is really a question of quality control...one catastrophic mis-launch could be fatal to a company Space X in its early stages...satellite companies want near 100% launch guarantee...looking at it optimistically it is a problem that should decrease over time as they gain experience and launches become more routinised.
I still think Musk is (correctly) very circumspect about his Mars plans. Had he wanted to, he could have promoted it in a Mars One fashion. But I think he does deliberately break it down.
My guess is that he is a middle aged man in a hurry and, so, while the MCT may be his long term vision, I think he probably has a more immediate mid term vision of how to get human beings to Mars.
For anyone, like me, who had lost touch with latest developments on Space X's plans for Mars, here is an illustrated article on the rocket development which would back up the plan:
I like your approach, similar to my views, though I wouldn't have the technical ability to express it as you do. Orbital docking/refuelling is clearly now well within our ability. We should be making full use of ISRU on Moon and Mars to facilitate missions.
The great thing about your proposal is, as far as I can see, you could fire the starting pistol now and within 8 years we could be there with a permanent station on Mars.
This is my variant, based on the Dragon and Falcon Heavy, for what it's worth:
I'd develop a relatively large capsule with a built in sidewall methane/oxygen propulsion system with a delta-v of about 5.2 kilometers per second. I'll paste the details below. It would be refuelable at a methane/oxygen fuel depot in low Earth orbit and at the L2 point between the Earth and the moon. It would have these potential uses:
1. It would be launched with a Falcon Heavy without a second stage, because the 5.2 km/sec of delta-v would allow it to serve as its own second stage. It would be capable of transporting a large number of tourists to low earth orbit; perhaps about 30.
2. If it were refueled in low Earth orbit, it would be able to go to the L2 Gateway or to low lunar orbit and be refueled again for a lunar landing. In either case, that refueling would be sufficient for it to land on the moon, then take off and fly back to the Earth.
3. If it were refueled in low Earth orbit, a delta-v of 5.2 km/sec is sufficient to fly to Mars and land there. Even better, if it refueled at L2 Gateway, it would have greatly increased capacity to fly people and cargo to Mars.
4. If refueled on Mars, 5.2 km/sec is sufficient to launch it into a high Mars orbit. It is not enough to fly straight back to Earth; it would need to be refueled in Martian orbit.
Such a vehicle could serve three purposes: transport of tourists to low earth orbit, transport of astronauts and tourists to the moon, and transport of astronauts to Mars. By having three possible uses, the vehicle (1) gets more use and flight experience, and (2) its development costs are sprad out among more users, making its use as a Mars transport vehicle cheaper and more reliable.
Here are the details below.
The Versatile Gryphon
The Gryphon consists of two sections, a lower propulsion module and an upper capsule. Its basal diameter is 6 meters. It has a 15 degree sidewall angle and a height of 11.5 meters. The top has a diameter of about 1.5 meters.
1. Propulsion Module: The propulsion module has a heat shield, tanks, engines, structure, and landing legs massing a total of 4 tonnes. It is 4.5 meters high and 6 meters in diameter on the bottom, tapering to 4.2 meters on top. Its total volume is about 90 m3. It has two sections in the Bloc-1 configuration:Lower cargo hold (height, 2 meters). It is on the bottom so that it is just a meter above the ground for ease of unloading and has a volume of about 40 cubic meters. Protruding into the sides of the cargo space are the four pairs of engines mounted in the lower sidewall. They fire outward at a 65 degree angle from the horizontal (25 degrees from the vertical). The sidewall below the engines may need ablative shielding or active cooling to protect them from the exhaust. The methane-oxygen fuel (Isp 380) will produce an effective “vertical” Isp of 344 and a “vertical” exhaust velocity of 3.38 km/sec. Engines located in this position are protected from reentry and are able to fire into a hypersonic airstream during the landing sequence.
Propellant section: The upper half of the propulsion module consists of a central fuel tank 2 meters in diameter, with six tanks arrayed around it, for a total of 7 tanks. The central tank holds 8 cubic meters of propellant; the 6 surrounding tanks hold 6 cubic meters each, for a total of 44 cubic meters. The tanks can be configured two ways:
20 m3 (8.4 tonnes) methane and 24 m3 (27 tonnes) LOX = 35.4 tonnes total propellant
30 m3 (2.12 tonnes) LH2, 6 m3 (2.5 tonnes) methane, 8 m3 (9.1 tonnes) LOX = 11.5 tonnes of propellant for Mars landing. The hydrogen can be used to manufacture 35 tonnes of ascent propellant2. Capsule: The capsule has three levels:
Lower deck: 4.2 meters diameter, 2.25 meters high (13.8 m2, 24.8 m3)
Middeck: 3.3 meters diameter, 2.25 meters high (8.5 m2, 14.3 m3)
Flight deck: 2.4 meters diameter, 2.25 meters high (4.5 m2, 6.7 m3)
Habitation decks total 26.8 m2, 45.8 m3The capsule has no heat shield because it does not separate from the propulsion module. Its total mass is 3 tonnes, plus a 1-tonne life support system. This is the mass of the Mars Direct ERV, which has about five times the internal volume. Cargo, consumables, and crew mass are variable.
Uses: Assuming the Gryphon has a total mass of 9 tonnes (4-tonne propulsion module, 4-tonne capsule, and 1 tonne for crew and consumables) and 35 tonnes of methane and oxygen propellant, the vehicle has a delta-v of about 5.2 km/sec.
Low Earth orbit: The Gryphon could serve as its own second stage in a launch from the Earth to a station in low Earth orbit. Depending on the size of the first stage and the delta-v it imparts, the capsule could be used to transport up to 30 to low earth orbit (a Boeing or Airbus jet aircraft provides 1.5 cubic meters per passenger in their cabins, on average; the Gryphon has 45 m3). By serving as a tourist transport to a LEO hotel, the gryphon’s development costs are amortized more quickly and the vehicle gains flight experience rapidly.
Lunar Transport: If the gryphon could be refueled in low Earth orbit (this requires creation of a fuel depot), it could fly from LEO to low lunar orbit (delta-v, 4.1 km/sec). There, it could be refueled for landing (1.9 km/sec) and return to Earth (2.8 km/sec from the lunar surface; total, 4.7 km/sec). Fueled with 35 tonnes of fuel in LEO, 15 tonnes can be transported to low lunar orbit (propulsion module, capsule, 7 tonnes for crew, consumables, cargo). If the capsule is configured to provide 3 cubic meters per passenger (Apollo provided 2 cubic meters per astronaut), it could carry 15 people to the moon.
Mars Transport: Assuming water is available on the Martian surface to manufacture methane and oxygen return propellant, a gryphon with just 1 tonne of payload (total dry mass of vehicle, 9 tonnes) could fly from low Earth orbit to the Martian surface using aerobraking (total delta-v, about 5.2 km/sec). Normally, it would fly to the L1 Gateway (delta-v from LEO, 3.5 km/sec) and refuel for trans-Mars injection and landing (delta-v, about 1.7 km/sec). The gryphon can transport itself and 11 tonnes of additional mass to the L1 Gateway.
A gryphon is not able to fly from the Martian surface straight back to Earth (delta-v, 6.4 km/sec). From a 1-sol elliptical orbit (delta-v, 5.2 km/sec from Martian surface), trans-Earth injection requires 1.2 km/sec. Thus it requires access to a Martian orbit fuel depot.
Other Configurations. The gryphon’s propulsion module can be used in several other ways.
“Bloc 2” Configuration. In the bloc 2 configuration, the fuel tanks are consolidated into two, one for methane and one for LOX, and placed in the bottom of the propulsion module where the cargo hold had been located. The top of the propulsion module then becomes an additional fourth deck in the capsule, increasing its volume from 45 m3 to 84 m3. This would allow the transport of 56 people to low Earth orbit and 28 to the moon.
“Bloc 3” Configuration. In the bloc 3 configuration, the entire propulsion module is filled with propellant tanks sized for liquid hydrogen and oxygen. The liquid hydrogen tank (60 m3) holds 4.25 tonnes of LH2; the liquid oxygen tank (23 m3) holds 26 tonnes of LOX. The 30 tonnes of propellant (Isp 450 seconds, effective Isp at a 65 degree angle, 408 seconds or 4 km/sec) can propel 9 tonnes of mass to 5 km/sec, essentially the same as the methane/oxygen configuration.
Hippogryph Configuration. The hippogryph or “hippo” consists of a bloc-1 propulsion module as an unmanned cargo vehicle. With 35 tonnes of methane/oxygen fuel and an empty mass of 4 tonnes, it can launch 15 tonnes to LEO, refuel, fly to L1 Gateway, refuel again, and land 15 tonnes of cargo on Mars or the moon. Its 35-tonne propellant capacity can also be used as an extra propulsion stage to push a gryphon and crew to Mars from the L1 Gateway. The “hippo” can aerobrake into Mars orbit and has enough fuel left over to provide trans-Earth injection propulsion to send the crew back to Earth.
Manned Mission Plan. A manned mission to Mars would start with the launch of a hippogryph cargo vehicle with 15 tonnes of cargo, including a pressurized rover that can be controlled from Earth, several small robotic rovers, one tonne of hydrogen feedstock, a large drill, and 3 tonnes of solar panels able to produce about 30 kilowatts of power. Mission purpose: demonstrate propellant manufacturing technology and characterize the outpost site. The pressurizable rover would power a drill to see whether water can be obtained.
Two years later, a gryphon would land to provide a backup launch vehicle for the subsequent human crew. Its 11 tonnes of cargo would include 2 tonnes of hydrogen feedstock, backup supplies, and possibly the surface shelter. A second “hippo” could also be sent with 15 tonnes of additional cargo, which might include communications/GPS satellites. Mission goals: refuel one return vehicle, provide the basics of an outpost, and extend power cables between the various vehicles, thereby establishing a “power grid.”
Two years later, two gryphons with 3 crew each (able to back each other up during the interplanetary flight) would be sent. Each gryphon would arrive with an additional hippogryph propulsion stage to provide trans-Earth injection at the end of the mission. Two additional hippogryph cargo landers would also be sent with another pressurized surface vehicle, more solar panels, greenhouses, and industrial machinery. Mission purpose: establish an outpost on the surface, a fuel depot/station in orbit, drill for water, and explore up to several hundred kilometers from the outpost.
Subsequent missions would transport 4 crews per gryphon, initiate ISRU on Phobos and/or Deimos, and explore outward to greater distances from the outpost.
"Red Dragon" is a proposal to launch a Dragon capsule to Mars via a Falcon Heavy. The capsule would contain a drill that would drill through the bottom of the capsule and then one meter into the Martian surface. It would be a NASA mission using Musk's hardware. The calculatin is that Dragon can land at least a tonne on the Martian surface; some think it could land 2 tonnes.
Another proposal involves landing a Dragon on Mars with a sample return vehicle inside the capsule. It would blast off through a port in the top of the capsule. The calculations suggest the sample return vehicle could be large enough to make a direct return to the Earth. The landing mass probably would be large enough to include a small rover to retrieve samples as well.
The way I keep track of Musk's plans are to check Space.com and spacedaily.com and spacex.com daily for anything new. Every few days I also check the Wikipedia articles on "Falcon Reusable," "Falcon Heavy," and "Mars Colonial Transporter." Occasionally I will also check the wikipedia articles on "Dragon," and "Raptor" as well. The footnotes for all these articles will take you to a great wealth of online articles.
Musk developed the Falcon/Dragon system for $1 billion over 10-12 years. Presumably the Falcon Heavy and Dragon will be fully functional, including reuse, by 2017. His bottleneck right now is that he can't launch things fast enough; his launch manifest is growing very, very fast and his launch schedule keeps falling behind. His price is already just about the lowest in the world. The French are panicking because no one wants to launch satellites with the Ariane; they are trying to push a new Ariane launcher that is cheaper, but it'll still be more than Falcon, even without reuse. With reuse, the price potentially falls almost 10 fold to 5-7 million dollars for 10 tonnes of LEO (with reuse, which cuts the payload from 13 tonnes).
What happens if he can launch for $1,000 per kilo ($1 million per tonne) and everyone else is launching for 2 or 3 times as much? Everyone will want to launch with him. He has pads at Canaveral and at Vandenberg in California, and will open his own spaceport in Brownesville, Texas, in a few years. Additional spaceports in Georgia and Puerto Rico are still being considered. He will need more pads to meet demand.
And what if he charges $2 million per tonne even though his costs are half that? He'd still be the cheapest and will make billions pretty quickly. The Mars Colonial Transporter will cost $2.5 billion more to develop. It is a 10-fold upgrade of Falcon 9, just Falcon 9 is a 10-fold upgrade of Falcon 1. The Mars Colonial Transporter will have a 10-meter diameter and thus can accommodate a 15-meter fairing. That would be quite an upgrade for the Dragon, but perhaps it'd cost a billion to develop; I think the Dragon cost $300 million to develop. The Mars Colonial Transporter will use methane and oxygen for its fuel, rather than kerosene/LOX, because you can make methane on Mars (the raptor engine supposedly will use methane and generate 1 million pounds of thrust). So I think you can see the outline of Musk's plan, from the existing information. A "Superdragon" capsule 15 meters in diameter and about 30 meters high, as a guess for its conical dimensions, would have 5,300 cubic meters of volume. That could accommodate a lot of people. If it massed 100 tonnes and used angled landing jets like the Dragon, it could probably fly 100 or more to Mars. If the Mars Colonial Transport's TMI stage retained enough fuel to land itself on Mars, the capsule could be hoisted back on top with a crane (in a few years, after they build a crane), the system could be refueled, and the capsule could be flown back to Earth for reuse.
That seems to be Musk's plan, but more details will come out in a few years. I think he could send people to Mars with the Falcon Heavy, but the Mars Colonial Transporter, if it actually gets built, will certainly be better.
Rob, thanks for the tips on how to keep tabs on what Musk is planning. He seems to let it out in dribs and drabs here and there, rather than as a published master plan - I suspect partly out of respect for NASA, on whom he has depended commercially (and might depend on for comms if the Mars project goes ahead?) and partly out of a canny sense that it might endanger the mission, from a political point of view if he gave it too high a profile (i.e. he doesn't want to start worrying the Senate, UN, and competitor nations too much).
There are some fascinating elements in the plan as it is developing.
It begins to make a lot of sense - take the crane parts with you and build the crane that will then allow you to hoist back Superdragons (or maybe just the ascent module??) on top of the reusable Space X rocket that has landed on the surface of Mars in a separate operation.
It seems like Musk is thinking big, in terms of direct transplant of human civilisation, rather than a slow ISRU-based growth rate.
If you can transport 100 people a time you can get 80,000 in 800 trips - at a launch rate of 20 per year, you could do it in 40 years...it all becomes a lot more credible doesn't it?
This is all very intriguing.
I have always thought Musk could fund a mission from his own resources with Space X but it now seems he can potentially fund a transplant of human civilisation.
I was intrigued by Rob S's comments on another thread:
"And Musk has already started developing the Methane-Oxygen Raptor engine of his "Mars Colonial Transport" which, if it is a triple barrel vehicle like the Falcon Heavy, will be able to launch 400-500 tonnes to low Earth orbit and land 100 tonnes on Mars. THAT'S a commitment! It'd be a nine-engine first stage, 1-engine second stage vehicle and would be reusable using the same system as the Falcon. Apparently he told NASA he could develop it for 2 or 3 billion and would even absorb the cost overruns. But they (or the Senate, to be exact) prefered the pork barrel 10-12 billion dollars SLS instead, wich will launch much less mass for a much higher cost per launch."
I thought it would be good to start a thread specifically dealing with Musk's plans.
What do we know exactly? What are the sources for information?
Here's a helpful recent news article:
http://www.dailymail.co.uk/sciencetech/ … 0-000.html
From the article:
"Elon Musk has previously said he created SpaceX for the sole reason of developing rocket technology to get people to Mars.
He wants to help establish a colony of up to 80,000 people on the planet, but admitted he’d like to start small, with a group of 10 people, and build the colony from there.
‘At Mars, you can start a self-sustaining civilisation and grow it into something really big,’ Musk said.
‘I think we're making some progress in that direction - not as fast as I'd like.’ "
Very much my vision, though I'd say start with six and aim for 100,000.
The article appears to link the Mars project to the reusable rocket.
Some questions I have:
How does the "Red Dragon" fit in with the reusable rocket? Is the reusable rocket going to be a supply vehicle only? How do you get the supply module off the top of the rocket on Mars without damaging the rocket or the supplies?
In terms of development costs, Musk developed the Falcon and Dragon for about a billion dollars. So inexpensive development is possible. If the Dragon and Falcon landing systems work--we'll know in two years--we'll have a way to land capsules and cargo on Mars. The Dragon's canted retrorocket system seems well suited for Mars.
A Falcon Heavy can push 14 tonnes of payload to trans-Mars injection, exclusive of empty stage. Zubrin assumed a hydrogen-oxygen trans-Mars injection stage --say, an enlarged Centaur--able to push 17 tonnes to trans-Mars injection and land 14 tonnes on Mars (this was in his Mars semi-direct proposal, using Dragon and Falcon Heavy). If we used two Heavies that docked together--one with a propulsion stage--we'd have a reasonably simple system able to push 28-30 tonnes of payload to Mars. That's close to the range of Mars Direct.
So I would design a system using Falcon Heavies if possible, since they appear to be large and cheap. Again, we'll be more certain in another year, when a Falcon is (hopefully) soft landed successfully, and a Falcon Heavy will have flown.
I agree entirely: use what is already there. If we can land 14 tonnes safely, well - job done. But I think we could probably do it more cheaply if we had the political will.
IN any case it is clear to me that for Musk Space X remains principally a way of getting humans established on Mars within his own lifetime. His eyes on the prize. If Musk becomes the man to get humans on to Mars he will be remembered for all time by the greater part of humanity. If he is simply a man who got stuff into orbit cheaply he will be of renown for only a few decades. The way he talks about getting to Mars being the biggest advance for humans since the neolithic revolution shows how big he thinks.
RobertDyck wrote:First mission:
- 1 SLS Block 2 for MAV (direct launch from KSC to Mars surface)
- 1 SLS Block 2 for lab & pressurized rover (direct launch)
- 1 Falcon Heavy for ITV
- 1 SLS Block 1 for TMI stage
- 1 Falcon 9 lander & unpressurized rover
- 1 Falcon 9 for Dragon
- 1 Atlas V 402 for Dream ChaserKeep it small so it happens. Big = not happening.
Looks reasonable until you start adding up the mission costs in launchers and the new R&D for the pieces not developed yet.... and do agree that with that mission costs we will not be going....Agreed it looks like the size of crew and ship are part of the issue when looking at the missions.
I think you'll find it you break down the mission into smaller parts it ends up being cheaper than you think. I looked into this before. We already have the technology to land substantial items on Mars e.g. Polar lander at half a ton. Much of the cost of the robot landers has related to the development of the robots. In terms of landing supplies, these missions would be relatively cheap, in the context of what people claim should be at least a $40 billion price tag for a human mission to Mars.
I've always felt a Mission based on six people in two separate landing craft, and with about 8 support missions landing supplies, hab, and energy generation in maybe two to three tonne loads are what is required. Make the human landers as Apollo Lunar module like as feasible i.e. short duration vehicles.
The Mars Polar lander, according to NASA, cost "$110 million for spacecraft development, $10 million mission operations; total $120 million (not includding launch vehicle or Deep Space 2 microprobes)".
Even if you quadruple that for 2 tonne supply loads, you are still talking about only $0.5 billion per landing mission. For 8 missions over an 8 year period building up to a human landing that would be a total of $4 billion (10% of a $40billion price tag), or $500 million per annum (last time I looked NASA's overall budget was something like $25billion pa).
So - eminently affordable.
I think you could do the whole of a 6 man mission for under $20 billion.
Launch costs are small change in this context.
louis wrote:I agree aerogel would be used to insulate indoor farm habs on Mars. But in terms of growing a self-sufficient economy on Mars, the colonists could make rockwool from basalt as insulation and simple reflectors could help maintain temperatures during the day or through heated water pools beneath the habs.
Actually, no. The equipment to make aerogel is quite involved. A science mission to Mars will bring an inflatable greenhouse, not anything solid like aerogel. And it will be a while before anyone on Mars will be able to make it. Expect the first greenhouse made with in-situ resources will be simple glass.
I said aerogel for a greenhouse on Earth. The website linked talks about growing food year-round. That means winter. I'm live in Winnipeg, Canada. We actually have winter. Your profile says you live in UK. Not sure which part, but weather statistics for London show average daily low for December, January, and February as 1°C, 0°C and 1°C. The same statistic for my city is -17.8, -19.6, and -11.6°C. In fact the average daily high for my city for January is -11°C. That's average, we can get a cold snap when it doesn't get above -20°C for a week. This year there were 90 days below -20°C, the most in 121 years. And that's the daytime high. This March one night it got down to -37°C. The coldest was -45°C one night in February 1966. And these are real temperatures, not wind chill.
Most older houses have double pane windows. Newer houses have sealed casement windows with plastic film stretched between the two glass panes, effectively creating a third pane. Some have 3 sheets of plastic, creating a total of 5 panes. It's to reduce heating cost. A greenhouse will have entire roof and walls of window. They'll need good thermal insulation. That's why I recommend aerogel for roof-top greenhouses on Earth.
I was talking about basalt fibres (rockwool) rather than aerogel.
https://www.youtube.com/watch?v=ENdjDzERKB8
Basalt has many uses and could be a key material on Mars for the early colonists.
A candidate for a Mars staple food perhaps?
Breadfruit:
Be careful with vertical farming. It stops being "free" when you have to add artificial light. Capturing tons of CO2 is more than negated by a coal burning power plant that generates power for this greenhouse. So this type of farming is only economical with ambient light.
You could use light pipes, or the more high-tech version: fibre optic cables. Those cables are just a flexible form of light pipe. It still requires as much light collection area as plant trays. If you can, just use glass greenhouse on building roof.
Aerogel will diffuse light, but light does get through. Plants just want lots of light on their leaves, it doesn't matter if it's diffuse. Aerogel provides much more insulation that glass panes because there are more transitions between solid and air. So aerogel would provide more thermal insulation in winter. Aerogel for greenhouse roof and walls?
http://upload.wikimedia.org/wikipedia/commons/thumb/2/2c/Aerogel_hand.jpg/220px-Aerogel_hand.jpg
It clearly has an energy cost, but it is much less costly in terms of fertiliser, pesticides, and losses to erratic weather.
I agree aerogel would be used to insulate indoor farm habs on Mars. But in terms of growing a self-sufficient economy on Mars, the colonists could make rockwool from basalt as insulation and simple reflectors could help maintain temperatures during the day or through heated water pools beneath the habs.
Been away for a while but it seems that the topic is about the most recent "Test of Mars reentry technology a qualified success" From Spacetoday.net
NASA declared Saturday's test flight of a Mars reentry technology demonstrator a success although the vehicle's parachute failed to fully open. The Low Density Supersonic Decelerator (LDSD) lifted off on a balloon from the Hawaiian island of Kauai at 2:41 pm EDT (1841 GMT) Saturday, raising to an altitude of more than 35 kilometers. At 5:05 pm EDT (2105 GMT), the LDSD separated from the balloon and ignited its rocket engine, accelerating to Mach 4 and an altitude of 55 kilometers. While one of the key technologies being tested by LDSD, an inflatable ballute designed to slow the vehicle down, did appear to work, another key system, a large parachute, failed to open fully. Project officials still declared the mission a success since the primary objective for this flight was to test the technologies for getting LDSD to the desired velocities and altitudes. Two additional LDSD test flights are planned, with the next in mid-2015. NASA hopes LDSD will successfully test technologies that can eventually be
used to land large spacecraft on the surface of Mars.The saucer was to expand from 15 ½ to 20 feet in width which is still less than a 10 meter which is what most designs target. The expansion was to increase the aerodynamic drag enough to slow the saucer to Mach 2.5, at which point a 100 foot wide supersonic parachute was to deploy and lower the test hardware to the Pacific Ocean.
From what I understand the parachute did not fully inflate which should have been easy here on earth but goes to show how hard using them on mars will be.
Quite - more risky on Mars = more risk to the life of the crew.
I think we already have the technology to land an Apollo style craft on Mars. Get the crew to the surface and then they can decamp to the hab unit ready and waiting for them. They will have emergency rations with them in the lander and also in the hab. But over the first few days they can then bring in supplies from other pre-landed craft. I envisage maybe 8 separate landings with 2-4 tonnes of supplies.
We've already landed close to a tonne. I don't think it's beyond our ability to do this.
The ADEPT chart shows 78 metric tonne mass for 40 metric tonnes landed on the surface. That's for aeroshell with heat shield, parachute, retro-rockets and propellant. That's just a hair over 50% landed payload. However, I think legs are included in "landed payload". Mars Direct habitat had a mass budget of 25.2 metric tonnes, so 40 metric tonnes is bigger.
But why does anyone think you need to land 40 tonnes on the surface in one go?
We have the technology to land multiple small loads over a number of years, climaxing with the landing of a self-erecting hab unit.
I doubt the human lander has to be much more than 2 tonnes, and of course we can have two for a total six person mission, with 3 in each.
NASA are over-complicating the problem and thereby making it much more challenging that it needs to be.
http://www.economist.com/news/science-a … -fantastic
This is v. much my vision of how indoor farming on Mars would work: v. space and energy efficient. But on Mars of course we would be interested in growing crops like dwarf buckwheat as well as the salad crops.
