Some people wonder why we should go to Mars. There's not much to profit by going there. In terms of mining, not much is useful there, plus asteroids are easier to mine.
The benefit is that a colony on Mars would be an engine of innovation. People keep pointing out that NASA has produced hundreds of useful innovations (like space blankets). Imagine how many innovations would a colony of 500 people come up with when stranded there for months and years. It's not that we send them there with only sticks and stone tools, they'll have the most advanced technology we can fit them with, but they'll still find themselves in thousands of situations where their tools will be puny compared to their problems.
Some in this thread mention boring machines. Well, just after a boring machine cuts a few meters of tunnel, someone lines that tunnel with some concrete elements. Where's the concrete coming from on Mars? Oh, I guess they can make it locally. Great, where are the components coming from? I guess you can mine them locally, but you'd need to bore some tunnels for that. A bit of a chicken and egg. What if the concrete does not set exactly like on Earth, because, you know, there's not enough humidity in their air (and there's not enough air either).
These guys will face millions of problems. And they'll have no choice but solve them.
Starting a colony on the ocean floor is also challenging and possibly leading to a lot of innovations [1]. However, compared to the efforts around Mars, there is no-one trying to settle the deep seas (that I know of). You don't need to go to another planet to find problems.
So for Mars, I don't think merely the opportunities for _any_ innovation, are a convincing enough argument, at least for those investing in Mars. For them the specific innovations around spaceflight and non-earth construction are indeed valuable, because of future expansions into space and first mover benefits, using Mars as a stepping stone.
As for the colony on Mars itself, I speculate that having somewhere outside of existing jurisdictions is also attractive for a lot of people; the new unclaimed West. Some may imagine this to become a scientist utopia, free from the restraining politics of Earth; others might be more cynical.
I don't think it's about space in general, but rather the vision of making humanity an inter-planetary species (at least that is what Elon Musk talks about a lot). I think the idea of expanding humanity beyond our single planet inspires a lot of people, myself included.
Fundamentally that is how it is different from colonizing the ocean floor.
Let’s send people to Mars where there’s a million reasons unknown and known they can’t survive so that they are forced to innovate to survive. Or you know, they die. This is a moronic argument for Mars colonization.
They’ll have the same or worse technology we already have on earth. They’ll have far fewer people and far less access to things to solve problems they didn’t plan for. But nah they’ll innovate and make great innovations, more than could ever be done here. I don’t wish to be rude but I honestly cannot understand for the life of me the rationale of this argument.
If we look at the reasons why people have historically colonised parts of the Earth, many of them would now seem pretty crazy. But craziness was apparently no barrier to entry. Perhaps colonists just are morons?
(Myself I think we'll go when it's easy. The best way to make it easy is to work on relevant technology like nuclear fusion, automated manufacturing, CRISPR, and so on.)
In support of your parent, I am thinking of the Polynesians. Arguably the most successful colonists ever. They drifted to previously uninhabited islands. Likely most attempts would have resulted in death in open ocean.
They didn't drift. They knew how to sail. How to transport live fruit trees over vast distances. The history of the pacific is really long and complicated.
There would have been indications in wave pattern. And they knew how to read these, as well as meteorological hints and knowledge of tides.
Nevertheless, in the context of this discussion, landing up on an inhabited island thousands of kilometres from here is a huge shot in the dark, and most hopeful colonists would have missed.
Landing up on an inhabited island thousands of kilometers from here is a huge shot in the dark, but you know you got air and fish, and you can survive even if your seeds don't grow, and you know you can leave if the island is not ideal for survival.
But on Mars, you don't have proper air and you don't have wild life for food. And you cannot easily leave for other better places.
>But on Mars, you don't have proper air and you don't have wild life for food.
Good point. It would make sense to send robots in advance to manufacture huge stockpiles of air and food. Which is of course beyond present technology.
Yes, there's no guarantee of finding a destination. That's one form of idiocy. Another, from today's point of view, is killing all the inhabitants (if any) upon arrival.
Citation needed that asteroids are easier to mine.
They win on arbitrarily long timelines, but they start to look a lot worse if you want ROI in under 10 years. It takes a ton of energy to reach and return from most asteroids in a sensible period of time. With unlimited time you can use various slow tricks to park them in accessible orbits, but this is a gold rush not a 100 year infrastructure project.
O'Neill had it right IMO, Lunar and Martian mass drivers firing up to Lagrange points are going to win. In the early days those bodies win because you can iterate on your mining tech way, way, way faster and keep up with the falling cost curve. In the later days economies of scale win the day.
Think about all the innovation coming out of military research. Like the internet - arguably more useful to humanity than the space blanket!
So should we spend trillions more on military? Well maybe it is just that spending trillions on research towards anything tend to lead to some useful inventions on the side. But what if we spent the same amount of resources on researching something actually useful for humanity? We might still get the side inventions.
Building a colony on Mars is a useless waste of money.
You are missing the part where the colonists go there on their own volition.
Trivia question: did you know that most of the Mayflower colonists died? Ahem, I mean, all of them died. All of us will die sooner or later, some people find it meaningful to go where no one has gone before, even if that means danger of death.
You do realize you can innovate here on earth right? And that you'll have a lot more money with which to innovate, because you didn't waste it all trying to strand yourself on another planet?
can't we just be honest with ourselves and say we want to do it because we have an innate desire to explore and expand our horizons? I think that's a good enough reason - economics should exist to support human endeavours, not the other way around.
There are already devices designed to melt the rock as it is being bored and use that molten rock to line the tunnel as the machine progresses. Not sure how that would impact your statement about needing concrete, but thought I would share anyway.
While I like the moon for those reasons, it has the downside of 14-day-long night and wild surface temperature variation.
While solar + batteries will last an Earth night or a Mars night, for something with a big enough population to be called a “colony” rather than a “base”, you suddenly find you need either a nuclear reactor, or some very big orbital mirrors, or a circumlunar powergrid.
None of these options are impossible, but they might make people prefer Mars.
There are places on the moon where there is quasi permanent sublight. These places also have some ice and are perfect for a moon base project.
Although not “eternal” in the original sense, they are sunlit for extended periods, well beyond the typical lunar day-night cycle.
What is the significance of such features? Permanently lit areas of the Moon are important for future habitation and use of the Moon for two principal reasons. First, these sunlit areas are prime locations for the establishment of solar photovoltaic arrays. The constant sunlight here means continuous generation of electrical power using solar panels. This solves one of the most difficult problems of lunar habitation, survival during the 354-hour lunar night. Prior to the discovery of the quasi-permanently lit areas, we imagined that the only feasible power source to survive this long night was nuclear reactors. Such a power system does not exist and would require several tens of billions of dollars to develop. So sunlit zones allow us to go to the Moon and stay there without this expense and technology development.
The second advantage of a sunlit area is that it is thermally benign. The surface temperatures at the lunar equator and mid-latitudes depend almost entirely upon incident solar illumination and range from less than -150° to over 100° C, a 250° temperature-swing over the course of a day. In contrast, the surface temperature of these quasi-permanent lit areas is nearly constant – a nice, toasty -50° ± 10° C. This simplifies the thermal design of surface habitats and equipment and greatly relieves the energy required for thermal control at an outpost.
The sunlit areas of the poles occur in close proximity to high concentrations of water ice and other volatiles at the poles of the Moon. Their presence indicates the lunar poles are the best places we have found off-planet for human habitation. Constant sunlight, benign temperatures, near the water and a great view – that’s prime real estate.
I personally like the idea of a colony on the Moon. In my mind I even have the killer app for such a colony: an astronomical telescope. There are 5 things going for such an telescope: 1. no atmosphere (so no need to deal with atmospheric turbulences in post-processing) 2. no radio chatter 3. no seismic activity 4. 14 days out of 28 the darkest night one can have inside a solar system 5. a little bit of gravity. The last one is something that can't be said about space-based telescopes like Hubble and James Webb. Having a bit of gravity means you can have people working over there. It means you can perform maintenance and upgrades. With Hubble and especially James Webb, what you send in space is what you'll ever get. So you better send something good. Once in space, there are no iterations, except software upgrades. Nothing like "move fast and break things". This necessary perfection at iteration number 1 makes the price of a space-based telescope skyrocket. JWST is projected to cost a cool $10 BN [1]. At that price, I'm sure we can build a whole Moon base and a telescope much bigger than JWST.
I believe this post ignores the implications of increased surface level radiation (Mars does not have a protective magnetosphere). See the two articles I link below.
A structure like this might make sense for a shorter mission - but considering the thought experiment asks what structure would be suitable for a long term Musk-style settlement I don't think thin ETFE would be enough.
At least part of the radiation risk is temporary solar events, so perhaps you could use a slightly hardened version of ETFE as the author suggests but keep all human activity near regularly placed deep shelters to retreat to when radiation spikes are detected?
The article's author points out that normal radiation on Mars is about the same as background radiation in Ramsar, Iran. Residents there have normal lifespans and cancer rates. Solar storms are a problem but fortunately, they give you enough warning to take shelter.
Thanks for this interesting link - I take back my criticism of the article! Based on your comment and that of t3hz0r it sounds like the martian colonists would be fine with this setup, as long as they mainly worked and lived in shielded habitats within the ETFE covered areas and also had underground shelters for emergency radiation protection.
I'll just point out that a Boring Co machine will fit inside a Starship.
Underground may be the only way to live, given that radiation dosage is cumulative, 24/7, it may not be possible to live on the surface at all in inflated domes. Maybe they're better suited for equipment storage and agriculture.
I think the implication is that under this tented tensile structure you could build whatever radiation shielded (or not) structures you wanted, and this just contains the air.
Radioactive particles (dust) in air are problematic. The gas in air does not become radioactive (at least in a dangerous way) from exposure to radiation.
If the surface of mars is exposed to radiation capable of making particles become radioactive, does that mean the surface is already radioactive? Or would this only happen to airborne dust particles, not to sand particles on the ground?
If you're breathing silica dust you're going to get silicosis anyway, so there's not much point worrying about it.
Maybe the living area buildings inside the tent can have a vestible / "dustlock" for keeping the dust outside, and outside those it just becomes standard to wear a dust mask.
If you’re putting all of your eggs in the “shielded other structures” - why have the other structure in the first place? It’s not as if you can live outside those “other structures” if you’ll just die of radiation poisoning.
Or, to put it another way, any structure capable of shielding against cosmic radiation should be capable of also holding air (we’ve gotten really good at that).
The biggest problem of these artificial environments is the threat of sabotage from either disgruntled, suicidal or criminal minds.
You can vet people as much as you want but with the pop they are talking about someone’s bound to go crazy or be an agent of discontent. And then if they are settlers of course their children can be as varied as they are on Earth, which means the possibility of the same.
I don't see where criminal fits in aside from the fact that a sabotage of that sort would rightfully be hideously illegal. What is to gain personally from that destruction?
It might be a pedantic quibble but I can see power as the only "rational" sabotage motive. Which could include some disgruntlement. Either to oust management or rivals to gain control or possibly international politics where one thinks they can gain from the loss of the colony for the sake of their earth nation.
Suicidal can be taken as granted to be irrational and disgruntled relatedly as "so fed up they want to see everything collapse to make them suffer".
Imagine beeing sentenced to a desert prison, by your parents, a monastry of eternal work and little fun, where all the beauty of world, is that coming from another world, as videos, games and mail, which you can never reach.
Maybe a part of the mission is to design a society to minimize or eliminate violence, mental illness, crime, etc. What would a society look like that depends on near-perfect harmony and peace for its very survival?
I would argue that it would be a dead society. It just takes one person who feels that being hurt themselves is worth it just to hurt others for whatever reason.
I thought going underground was the way to go. I wasn't imagining a "pressurized tunnel" but rather a pressurized underground complex filled with tunnels and rooms (minecraft).
But maybe pressurizing an underground complex with walls made out of ...Mars is more difficult than building something on the surface?
Going underground seemed like it had limitless room for easy expansion.
I like the authors suggestion and it does sound better than a dome but living underground seems safer to me.
Yes, it is curious that natural land features are not exploited more. You can put that city wherever you want on Mars.
Cover a canyon (walls for free). Use lava tubes. Or search for any peculiar geological feature that is amendable. I don't get why the assumption is a completely flat, desert surface.
This is partially due to (current) landing site requirements. Up till now landers targeting mars could not really handle any bigger terrain obstacles (big rocks, steep slopes, etc.) so the landing sites have been meticulously selected to be as flat and rock free as possible.
That's why photos from different Mars landers look often very similar - the regions they have landed in have been effectively selected to be similar. :) And of course these pictures shape how Martian surface looks like the public consciousness.
Things may be changing though, with the technology being developed for active obstacle avoidance, that might enable martian landers to land in a more complex terrain safely by analyzing the actual landing site and landing on a safe spot.
Still, you might still want some flat area near an early martian base/city, even just to make trucking stuff from/to landers that strayed of course during landing easier. Eq. not having one in the middle of a rock field and another on crater bottom. :)
Maybe. But if you have a canyon, you can use three natural sides, cover the top and one side. The side you can expand as needed.
Cities on Earth don't need to be protected from toxic soil and hard UV radiation. Instead, most cities on earth have been built near rivers for cheap transportation. Castles and fortifications are built on hills for defensive value.
On the other hand, cities on Earth are very often bounded by other natural features like rivers and mountains that naturally constrain easily-usable space. On Mars it would seem to me the solution to needing more space would be the same as on Earth - build another city.
I'd think an inflatable habitat inside a lava tube would be ideal. For the Moon, it'd be perfect - lava tubes are supposed to have lots of ice in them.
There are photos of lava tubes that are hundreds of meters wide and kilometres long. That's a lot of space shielded from radiation.
I’d imagine building out some new support pillars and flexible ceiling would be much faster and cheaper than digging out the same space underground.
I know tunnel boring is supposed to be getting cheaper and easier, plus on Mars you’d be starting from a blank slate rather than working around/under existing infrastructure. But for big tunnels you still need a big boring machine, and that would either have to be shipped to Mars or built on Mars.
I personally suspect the main reason for going above ground is morale and psychological essentially to have some sunlight and a view of the world they are settling to validate the purpose on an emotional level.
I am uncertain of the ergonomics of living spaces in artifical environments - I suspect even the experts are uncertain and even if they invested heavily they would discover design mistakes to correct in future iterations.
> It turns out that the main advantage of domes – no internal supports – becomes a major liability on Mars. While rigid geodesic domes on Earth are compressive structures, on Mars, a pressurized dome actually supports its own weight and then some. As a result, the structure is under tension and the dome is attempting to tear itself out of the ground. Since lifting force scales with area, while anchoring force scales with circumference, domes on Mars can’t be much wider than about 150 feet, and even then would require extensive foundation engineering.
The solution here seems fairly straightforward: don't make the design completely pressure-supported, but include enough weighty structural elements like ribs and beams to make it heavy enough to be a compressive structure again. If you have a rib-like structure on the top side of your dome material, you could even just pile Mars dust and rocks on top of it to keep it in place.
sand/dust blows around into dunes and its dense enough that "close enough" won't hack it. Figure as an engineering 1 sig fig estimate (dry) sand runs around a twentieth of a pound per cubic inch, so 14.7 PSI air would be in compression with around three hundred or so inches of sand evenly spread around the top.
Its a major labor sink to build and maintain and dunes could cause a catastrophic failure. Could make an interesting sci fi novel about "emergency EVA to run bulldozer drones to spread sand to prevent dome collapse".
In the end, rather than the nightmare of making a 3000 meter diameter dome deep enough under ground that dune forces will have no effect (using h-bombs to excavate?), just make thirty 10 meter diameter tunnel boring machines and run them 10 kilometers in different directions.
The linked article's tube tent is not a bad idea for surface greenhouses.
Does it need to be more extensive than "make the very bottom ridge of the dome wider than the dome itself (some kind of "lip") and place it into the groove carved in the rock?
Yes... Remember that there's 1 bar of atmosphere in there. 150 feet (45m) makes for a circle of 140m circumference but 1600m^2 area. Since 1 bar ~= 100_000Pa, each of that square meters has 100KN of upwards force on it, for a sum of 160MN distributed over 140m of circumference or ~1MN per meter. So assuming the mass of the dome is negligible, we're talking about the equivalent strength of holding on to a mass of about 100 metric tons (compared to Earth gravity) per meter of dome. Ie. the amount of support you need per meter is the amount that you would need on Earth to hold up 100 metric tons against gravity. That's about a Boeing 737. Per meter.
That's why the author suggests peridiodic anchors, like an air mattress. As other commenters have pointed out, you don't want the structure to deflate in the event of decomp, so a strut which is useful secondarily in compression is useful here.
Basal fiber is about 3GPa tensile, call it a MoS of 6 for a neat 500MPa working strength.
If you plug int wolfram alpha `1 atmosphere * 1 square meter / 500 MPa` you get 2 cm^2 of support (tethering) per sq m of roof. That's reasonable.
But here's the rub: compressive strength lags tensile strength. Even granite is a mere 130 MPa. So even a strut which has some compression resiliance is not gonna be enough to fully abate a collapse. So it's very likely a Martian structure would have some arc to it, as it both benefits tension under nominal operation and some compression in failure mode, at least long enough to keep pressure from dropping too low.
I imagine rip-stop at all sorts of scales will be implemented. It's not gonna be like an inflatable golf dome.
Steel cable with a diameter of 1inch has a breaking strength of 47 tonnes. Give it a safety margin and assume it can hold 10 tonnes. So you need 10 cables per meter. So I assume in case the "lip" being just a sheet of steel it can be way thinner than 25mm.
Sure but you need to be sure that the thing you're attaching it to can hold the weight. Ie. if the martian floor was the ceiling, you'd have to be able to hang a plane off that attachment point without it ripping out.
In other words, your lip needs to be distributing force onto a sufficient volume of ground to make up 100_000 metric tons of martian soil, per meter of circumference.
I would suggest a refinement. The author proposes that the vertical cables be anchored in the ground with driven piles. This ought to work, but it’s ignoring a detail: the Martian surface is presumably permeable enough to air that the bottom of the structure would need to be lined. If the bottom were strong enough (e.g. the same material as the top), then the cables could be anchored to the bottom material. No piles needed. The resulting structure would look very much like an air mattress sitting on the ground, and air mattresses don’t need to be staked down.
Just curious though -- I'd always assumed domes were just a fun sci-fi illustration/trope because they look cool -- not that they were necessarily taken seriously by engineers.
Is the author just responding to that sci-fi concept (same thing as, spaceships don't make a whoosh sound in space), or are there more serious Mars plans that have genuinely proposed domes? I feel like the author isn't quite clear who he's responding to.
OK. Let’s assume the technology works out, and that this is realistic:
> the Mars city will need teams of specialists
> On Mars, SpaceX hopes to get by with “only” a million people and a lot of manufacturing automation
> What is the per capita area requirement on Mars? In a future post I’ll estimate this more rigorously but I believe it’s on the order of 10,000 sqft
How do you bootstrap to get there?
> If a Mars base is doubling its population every launch window, then the 5000->10000 person increment
So, let’s say you are such a specialist. What would entice you to sign up for one of the first flights?
Given the disadvantages (a return flight will be years out, if ever in your lifetime, and those in the first 10 or so flights will have to trust that 200-ish further flights will follow) I doubt ‘fame’ and ‘adventure’ will cut it (possibly for some people, but try finding 25,000 or so for those first flights, with the restriction on getting a good mix of expertises and a good psychological mix)
I can think of:
- coercion by your government
- Earth being wasted enough to make Mars look enticing.
- lots of unmanned flights, to ensure that the first flights going there have an escape vehicle, if needed.
Assuming my family is grown (and thus my direct life responsibilities fully attended), I'd sign up.
Recall the older generation that cleaned up at Fukushima.[0] These are folks that knew their activities would be uncomfortable, may cause their death, but ultimately was absolutely vital to the benefit of all mankind.
This view on life is not constrained to a single culture or background. Self-sacrifice in such a way is often considered the highest pinnacle of morality -- even under the auspices of selfish genes since the act does not directly benefit descendants. Planting trees in your later years that the fruit may be enjoyed generations after.
You may ask if I have any special skills. I do, but suppose I don't. In such a place you will need grunts. And I'd be happy to join in to build humanity's insurance policy to be a bit broader.
All depends on the cost-benefit evaluation at the margin. To fill the resource, the prime candidates may be too few to recruit, and the people with grown children still relatively young and healthy available to make the trip and contribute sufficiently.
What happens when the tent loses pressure? Wouldn't you then need fallback supports with compressive strength? Although assuming the force exerted by pressure is at least twice that of gravity (so that pressure minus gravity is still greater than gravity by itself) the requirements for the fallback supports probably don't have to hold as much load.
The whole thing would collapse. However, given a big enough scale, it would take a long time even if there was what we would think is a big hole in it. But even then, they'd have to have a number of contingency plans; a supply of compressed air that can be manually released in case of a power outage for example.
I don’t understand the dedication of resources to solving problems on Mars when we have plenty of unsolved problems that affect people that are alive today and suffering. Maybe they don’t have the allure of private profit but I think it would be much more valuable to figure out how to grow and distribute food in food insecure places than to figure out how to grow and distribute food on Mars in addition to figuring out how to get there in the first place.
India's space program is a huge point of pride for their country (and rightfully so).
They have problems to solve. It doesn't mean that it's wrong to spend a (relatively) tiny amount of money to give people something to aspire to, and to take pride in accomplishing together. We can do two things at once.
You're only focus on the space program because it's technically similar to food insecurity. But you're ignoring the 50% of the economy which is focused on -- let's be honest -- irrelevant shit. Incredible sums of money (and time and effort) go towards entertainment (hollywood), fashion, jewelry, vacations, and other luxuries.
If you want to divert more resources towards solving world hunger, take it from Hollywood. You don't need to strip bare a source of inspiration that unites people and moves humanity forward.
It’s valid to spend money on entertainment as an individual and all economies in the world have significant portions of the productivity of their population going towards “irrelevant shit”. India spending money on a space program seems like an insignificant amount of money to me compared to their total population and is likely not enough money to solve their food problems. We agree on this part. I spend money on vapid shit every day and so do millions of other people. They’re not bad.
But, total resources for a Mars colonization effort seems like an order of magnitude more expensive than a simple space program for the benefit of an order of magnitude fewer people. In addition, the capital that is contributing to these efforts (ie Bezos and Musk money) is much more concentrated and can be mobilized in a much more precise manner. I don’t see Mars colonization as a source of inspiration outside of these SV types, and that’s not a significant enough population for me to find this justifiable.
One problem is political, and therefore not solvable. We wouldn't like most of the ways it could be made solvable, and I'm sure there are no ways that everybody would approve of.
The other is technical (for now) -- hard, but trivial.
I think this is it. Difficult problems seem way more difficult to actually solve than technical problems at the end of the day. I just wish that helping other humans was seen as a good enough reason to supersede these political difficulties.
You’re gonna have to provide a bit more context for that challenge, considering all the information already available about it. Which figure do you think is wrong?
It takes billions of dollars and many years just to construct things like subway systems in developed countries.
The only way I see a mars mission happening is launching remote controlled equipment over the course of decades to the red planet and building and preparing everything as much as possible before so much as the first human arrives. I don't see any other way it happens with how expensive and risk averse we are as a society these days.
And even then, the likely scenario is sending and constructing return vehicles for a very short human mission.
And that's all assuming we figure out how to get people from here to there in a space ship for so many weeks in the first place!
Maybe I'm just more pessimistic than the average HN user when it comes to sci fi stuff like this, I don't know. I just can't see humans investing the money to get over all these hurdles for a colony that we don't even know could work out currently-- we can't even make self sustaining habitats here on earth!
> It takes billions of dollars and many years just to construct things like subway systems in developed countries.
Much, if not most, of that being spent on lawsuits, as people block construction projects, hoping to extract maximum value for themselves now that they know the society needs their permission.
Having this in mind, I wouldn't be surprised if building infrastructure on Moon or Mars ended up being cheaper than in the US - there are no land owners up there just yet.
I'm pretty sure it's not true as most subway systems outside of the US (where we are not as lawsuit-happy) still cost billions of dollars and takes many years to construct.
> assuming we figure out how to get people from here to there in a space ship for so many weeks in the first place!
Why do you think that's an unsolved problem? Genuine question. I thought that part is a straightforward engineering problem. (A very challenging one of course. I'm not saying it's not, just one where we have a lot of previous experience. I never thought that the fundamental possibility of it is in question.)
Well there are no solid designs on the table for doing it. Mostly because it's a chicken and egg problem of making plans to send people somewhere they can't come back from right now. But it's far from just an engineering problem; there is a huge human element to it:
For instance, we don't have a lot of experience with large groups of people in space for that long. We're talking at least 7 months each direction if they're coming back, plus waiting for the return window and executing it. That's an insane experiment in low gravity isolation that by itself hasn't been tackled-- most astronauts are only in space for 7 months at a time on average for a trip, and they need varying amounts of recovery afterward. We're talking about twice that, for an entire crew, plus time spent on the ground on mars in a lower gravity field than here on earth.
Then there's the fact that the crew will need to be large to be sufficiently redundant... and that runs into the problem of having many people in a small isolated space for such a long period of time. I think the largest crews we've had up there were around 10 people. A mars mission would need enough people to prevent everyone from dying if something went wrong on the way there, the wait for the window, and the launch for the return trip, and the return trip itself. I don't think we know how many people that would take currently.
I don't think we can confidently say that it's even possible until we have more experiments studying those things alone.
I'm not at all an expert these are just layman opinions and observations, so if I'm off base I'd like to know. But that's how I understand just the problem of going there.
> and that runs into the problem of having many people in a small isolated space for such a long period of time. I think the largest crews we've had up there were around 10 people.
Challenges of low gravity aside, this doesn't seem that different to a modern submarine. We have nuclear submarines with crews of ~150 that stay submerged for months at a time - the navy has to have some idea how to address the cultural problems inherent in packing 150 people into a tin can...
Regarding the time it could take to travel between Earth and Mars, I recently saw a very interesting video on a concept called a "skyhook" that suggests it might be able to economically reduce the transit time to "just" two months or so, though I assume you'd still want to wait for an appropriate launch window, and in addition it probably wouldn't be operational in time to benefit the first few generations of travelers. :P https://m.youtube.com/watch?v=dqwpQarrDwk
I don’t know why people can’t face the facts. Maybe someday there will be the technology but right now it’s like cave men trying to build an aircraft carrier.
> It’s a pitiless frozen vacuum. The Earth’s south pole in the middle of winter is closer to a beach in Hawaii than the nicest place on Mars on the nicest day of the year.
Wow, on the surface pictures made by the rover, it looks like a hot desert. I understand that the lack of water causes this drastic difference in appearance, but never would have imagined the difference to be so big.
It’s the near-vacuum, plus the radiation environment, mostly. Temperatures on Mars can rise above freezing in the tropics, on a particularly warm summer day, but the average temperature on the planet is several tens of degrees C on the negative side. The author’s point is, I believe, that even in the southern polar night a human being can survive, for a while, with stone age technology. Whereas if the atmosphere around you isn’t breathable there’s not much you can do without (literally) space age gear.
The common conceit I see in these designs is trying to use a single pressure vessel instead of nested ones. Humans only need a couple PSI to avoid physical damage to skin and eyes, and if you just leave most of the nitrogen out if the air you can drop the pressure significantly, still breathe, and not set things on fire (flammability is tied to oxygen partial pressure). But even then, a single fault in the system leaks all your air out and everyone dies.
Space habitats so far look more like submarines. It’s a bunch of tubes with bulkheads. But they don’t scale, and some of the biggest ones so far are in fact inflatables.
If you nested inflatable structures, the forces on them are due to the pressures between the layers. You could run an outer chamber that requires a respirator, an inner one for living space, and a third for medical. An alarm system in each layer could begin capturing atmosphere in the event of a breach, with emergency venting for over pressure. You would only risk half of your air to a single failure.
The Eden project uses hexagons panels that resemble a blister on bubble wrap. No accuse angles there. And why can’t you cable a dome down the same as this design?
The idea of a dome is volume. If you aren’t going to build upward in the dome, why bother? Building upward avoids interfacing with the envelope.
If you could work out how to construct a dome over the top of an existing dome, you wouldn’t even have to move. Just deconstruct the inner dome and begin expanding outward.
This is all covered in the last third of the essay, including nested structures, depressurization and the proposed structure has much, much higher volume than a dome.
Does he though? Felt like a throwaway sentence to me.
Also, his idea about hanging buildings from the wires is bunk. If you hang your buildings from the tensile structure that is buoyed by air and you have a rupture, now your buildings are going to collapse. Likely onto other buildings. Since his design has no compressive strength at all there is no way to address that issue.
[edit] what makes it more bunk is that in order to have tall structures, the entire habitat has to be the same height as the structure, instead of placing them near apex of a hemispherical structure. So he's just doubled the volume versus a sphere. Also if you make a bubble structure that tall you have to handle the pressure on the walls. I don't see where he mentions walls at all except when talking about how dome walls suck. Not as much as trying to pressurize a rectangular pressure vessel! The only place his solution shines is in 'doming' a valley or a canyon, where a dome has a host of other problems he hasn't even covered.
I can't remember if the bubbles on the Eden domes contribute strength to the structure, but I expect you could design them to do so. Then the structure begins to more resemble a bouncy castle (like the ISS inflatable hab unit).
This is very similar to an idea I've had about terrestrial weather protection. I wanted to use square ETFE pillows filled with hydrogen and tethered down to make a flat roof over an area. Flamability is a concern, so testing is required. I think it will be fine if I fully surround each hydrogen filled pillow with nitrogen filled ones.
You could use nuclear weapons to dig a bunch of upside-down domes into the ground and seal the tops. It would only take a couple of years for radioactivity to reduce to the point they could be inhabited without protective clothing.
you get the advantage of just having to ship an inflatable skin and then you just dig out a hole some fraction of sphere, put the bubble in and then fill the dirt back inside the bubble, now it's pressure supported and anchored.
As an aside - in the Kim Stanley Robinson Red/Green/Blue Mars series, the tents are supported, rather than solely relying on pressure. This includes the use of aerogels (or "airgels") for the struts.
Question: if we build such a structure and make really high, like 200m or more, would the denser atmosphere provide significant protection against the more nasty solar radiation?
I would guess by coating the floors/ground with sealing coating (and walls and ceilings if you're underground).
It might need to be nice and thick to withstand wear, but maybe not that thick depending on how tough the sealant is, how regular the surfaces and how well maintained.
ya, you'd need multiples of these anyway, just for the redundancy. That said, it's fairly straightforward to put up separate walls that seal different compartments. The rectangular shape makes expansion and inter-zone connections a lot easier. Many air mattresses use similar techniques, and most inflatable watercraft have that redundancy.
I find the popular colonialist view of space travel problematic, because if it comes to fruition, then that means that earthlings couldn't figure out how to take care of themselves. I don't see our salvation in the destructive exploitation of other worlds.
Orbital manufacturing will pay enormous technological dividends and help take care of Earth.
If you step out of the parochial world where we happen to live on this planet, the fact that every one of our manufacturing processes is built around an ambient acceleration of 10 m/s^2 is weird and limiting. Beyond the freedom from gravity, orbital manufacturing provides for absolutely perfect vibration isolation (see LISA mission for an example).
Made in Space Fiber / FOMS is just the tip of the iceberg. Semiconductor fabs are going up there sooner or later.
It's not about energy, it's about processes that literally don't work on Earth.
See Made in Space fiber[0] for an early example - they're producing best-in-class optical fibers which can't be made on Earth because convection introduces crystalline impurities. Their value per kg is attractive enough to make this a profitable business with today's launch costs.
As launch costs drop and people explore this space we're going to discover a _lot_ of such problems.
Solutions / mixtures essentially don't separate in micro-g so you can grow much better crystals, smelt very high entropy alloys, do all sorts of awesome tissue engineering, etc.
The vibration isolation thing is also a huge force multiplier for all this. Ultra-precision manufacturing is a game of complete and total process control. Right now we spend absurd sums on isolation systems to block vibrations from the truck driving by half a mile away. In orbit you just make sure anything with moving parts is on a separate free body from your isolated component and they fly in formation. The LISA mission is doing this to position ultra-perfect reference objects and detect gravitational waves with baselines measured in thousands of kilometers.
Release a bunch of balloons into the air. They'd float to the leak.
If you want to get fancy, coat them with a glue that bonds to the ceiling material, and they'd fix the leak too! At least temporarily. My first thought was that they'd clog the hole automatically even without glue, but I think the pressure differential would just squeeze them through.
Assume it was feasible to create a breathable atmosphere on Mars - that you could just melt the polar ice like in Total Recall, and boom, instant blue skies. Ignore the radiation Mars has been bathed in over the aeons, the toxicity of the soil, the low light levels which might make photosynthesis (and, thus, an ecosystem) impossible, and the lack of a magnetic field to shield the planet from solar winds[0]. How would you keep the necessary amount of atmosphere on the planet given its small size and gravity relative to Earth?
Why did the author go to all the trouble to write this when within their own argument it’s obvious that it’s impossible for humans to survive and flourish without Earth?
The way I would do it is send a lot of self replicating terraforming robots. That requires relatively little cargo - the only components that cannot be manifactured on mars directly are smd and processors.
I have a Nobel prize and a billion dollars of VC money right here in my back pocket. All you've got to do is demonstrate your design for a self replicating general purpose constructor robot. Actually anybody's demonstrable design will do, and I'll give you a sweet cut of the VC money.
As reductive as "just send self-replicating robots" is, it's still potentially easier than a self-sustaining human civilization like the article is talking about. Both require building the entire set of infrastructure to build industrial infrastructure and computers. The robot approach requires that every single factory and excavator is automated* - a huge feat. The human approach requires every piece of infrastructure the robot one does, plus the infrastructure to make pressurized domes, oxygen, food, heating, etc, etc, and also requires shipping large numbers of humans through the vacuum of space - also a huge feat. I don't think it's a given that either approach is easier.
* At least, automated enough that it's not bottlenecked by humans operating robot arms at a 30 minute feedback delay.
Aside from we don't know even in theory how to do it, which is a bit of an obstacle to overcome, I don't see how this could work without developing AGI first to operate it. That's probably at least a couple of trillion worth of R&D right there, and then again we don't actually know how to start on that even in theory.
In total the US already spends half a trillion on R&D per year. The US military spends a trillion on R&D every 15 years and the IT industry does about the same, and bear in mind most of the research these organisations are already doing would be directly relevant to a project like this. So in a way we're already doing it, and I don't see any from-scratch full-civilization self replicating technology architectures coming along on the horizon even as a theoretical exercise. Even for something like interstellar probes at least we have outline designs.
Not that I believe we are anywhere close, but processors could be made on the moon. Maybe not modern ones, but working ones. Also if space is not a problem, quite large ones too.
Have the man studied engineering? I don't feel so. Too much drama for a trivial issue.
Point one, if a dome is in tension, you have not put enough weight.
Point two, tents are more manufacturable and robust for as long as cost is concerned.
Point three, massive human space colonisation will only happen long, long after we will get manufacturing automation, automated resource extraction, automated farming, and power production to "sci-fi" levels and above.
We are not even 1% done on that, and that's the biggest point. Without getting to at least 1% on that scale, the talk about even ~100 people research outposts in space are pointless.
Adding to that, once humanity will reach that level, the entire idea of going to space for something we don't get on earth will look silly.
Once we get robots to the point where one can get a skyscraper constructed with a single mouse click, it will likely wouldn't matter much more if that skyscraper will also have to be airtight and have life support installed.
> In an open system, an effectively infinite supply of natural raw materials can be used, and wasted, as needed. The Mars city solves this problem by building on the surface of a planet that is made of all the raw materials it could need.
It makes me sad to think that exploration and settlement of the solar system would take with it this kind of thinking, which is dangerously close to rendering the Earth uninhabitable.
The Earth (and Mars...) are, in some sense, closed systems, in that exploitation of resources has a hard limit beyond which we're looking at biosphere collapse, or just plain resource exhaustion.
Maybe we could use space exploration to come up with a different way, and then roll that back into how we live here on Earth.
I think a lot of those concerns disappear once you leave Earth. What makes our planet precious is how uncommon it is. The universe is incredibly vast, yet we have not observed life on any planet but our own. So to me whatever the cost is to a planet like Mars of putting life on its surface, that cost is well worth it (the planet certainly doesn’t mind). The only ones who might be offended by this idea are us Terrans.
Idk... To me, terms like "exploitation of resources" tend to be overloaded with connotations to "think past" concretely.
People have a big impact on our environment, and the definition of "environment" keeps ratcheting up with the scale of humanity... As the number of people, the scale of our impact, and our knowledge of this impact our definition of "our environment" expands.
That's not likely to change. We're not going back to our environmental niches and we're not going to be a impact-neutral observer of "the natural environment" either. We're going to maintain our place between gods and beasts, so to speak.
That doesn't mean we don't/won't evolve. There is definitely no sense and future in bluntly walking in to environmental hard-limits like climate change, biodiversity crisis or any other pressing catastrophe.
But.. perfecting ourselves to the point where we've "moved beyond" resource use shaped by our wants and needs, exploitation...
In any case, I think the environmental ethos of the future can be left to future people. It will inevitably be shaped our ours' mistakes, and their consequences.
The benefit is that a colony on Mars would be an engine of innovation. People keep pointing out that NASA has produced hundreds of useful innovations (like space blankets). Imagine how many innovations would a colony of 500 people come up with when stranded there for months and years. It's not that we send them there with only sticks and stone tools, they'll have the most advanced technology we can fit them with, but they'll still find themselves in thousands of situations where their tools will be puny compared to their problems.
Some in this thread mention boring machines. Well, just after a boring machine cuts a few meters of tunnel, someone lines that tunnel with some concrete elements. Where's the concrete coming from on Mars? Oh, I guess they can make it locally. Great, where are the components coming from? I guess you can mine them locally, but you'd need to bore some tunnels for that. A bit of a chicken and egg. What if the concrete does not set exactly like on Earth, because, you know, there's not enough humidity in their air (and there's not enough air either).
These guys will face millions of problems. And they'll have no choice but solve them.
It's going to be awesome.