Well - it's not so much that - it is like how long is a piece of string - how many people count as a colony? But - an easier comparison is to look at -whether space colonization can make financial sense for individuals - how easy or difficult is it to build a house in space? In particular, how much more expensive than a house built on Earth?
It's a bit like solar photovoltaic panels. For as long as solar panels were a far more expensive way of generating electricity - even if you were green - unless you were very wealthy, you didn't have solar photovoltaic panels. Now the cost has gone down, many have them. Make them cheap enough - and you don't need to find a way to pay for huge numbers of solar panels for everyone in the planet - they will buy them for themselves. So then "the cost of making sure everyone has solar panels" - is kind of irrelevant. What matters is the cost for an individual and how that compares with their other options.
As it is now, any habitat in space has to contain ten tons or so per square meter outwards pressure. So - basically talking about a tank type construction, but your buildings far more expensive than tanks, and stronger than them.
It also has to have cosmic radiation shielding to protect you - so that's about 4.5 tons per square meter shielding on the outside. And few windows - those are hard to build in space conditions - and if you are living there long term - you want the whole thing shielded if possible - will probably have view-screens rather than windows.
And - as well as that - needs some way to generate your air from ice. And some way of making a circulation system to get rid of poisonous gases. We don't realize it - but houses have to be ventilated to stay healthy, okay. But now imagine your house is totally airtight, not even air can get in or out?
That is - unless we can sort out closed systems using natural methods such as plants, trees etc - that would make this part far easier.
So depends. If we can get that to work, this bit is far easier.
But using present day technology, in space stations, totally air tight, you'd get a build up of all sorts of poisonous gases such as methane, hydrogen sulfide etc. And you have to keep scrubbing the CO2 out of the air because that is poisonous for humans, even when there is enough oxygen to breathe. And harmful microbes also build up in space habitats - they keep the air of the ISS very dry to reduce the build up of microbes - and still have to filter them out as well.
And either way, you have to grow all your food - not in open fields as we do here on Earth - but always in greenhouses. And those greenhouses also have to contain tons of outward pressure. And probably need artificial lighting as well.
And have to deal with the build up of wastes - a human generates tons of waste every year - what do you do with it all? Can you recycle it? If so how? Can your plants and ecosystem cope with human wastes? Or do you use machines for those?
And add to that - that any time you go outside your habitat you need to wear a spacesuit. And that spacesuit - it's not just like fancy clothes you wear like a raincoat. It's an immensely complex bit of hardware. Basically it is a mini spaceship in its own right, able to contain an environment inside of it that a human can live in - and with a thin covering easily breached - and you die within seconds if you have an accident. And long term spent outside your habitat and you increase your lifetime risk of cancer from cosmic radiation. So people aren't gong to want to do that. Most will keep indoors if they possibly can - just as they are cautious about getting skin cancer here on the Earth.
In any case - it's very clumsy. So - you can't just go out with a shovel, chances are you do most of your work from inside the shielded habitat driving machines around via telepresence.
And - in the stressful environment of space - I mean mechanically stressful - your house, built like a tank but more so - it's still not going to last that long. Not like the centuries with minor repairs of a house on the Earth. The reason is because it goes through huge temperature fluctuations every time part of it goes into shadow, and long term, little cracks build up and destroy it.
So, chances are, more like a few decades, like the design life of the ISS - then probably you have to build a new house again.
Clearly - this is nowhere close to competing with the building costs of a house on the Earth. Or of starting up a new farm on the Earth - even if it is in a desert and you have to cover all of the acres of your farm with greenhouses - and supply them with sea water piped from the sea - and then back again - evaporating to create water and cool down your greenhouses at the same time - as in the sea water greenhouses project - still - you are talking about just a fraction of the cost of a space home.
So - how much is a house like that going to cost? Surely, even when the prices go right down, even if it was as easy to build in space as it is to build on the Earth, it would still cost, like a hundred or a thousand times more than the same house on the Earth don't you think?
Even the same house + fields to grow crops constructed on an Earth desert, or floating in the sea, or floating in the upper atmosphere in a "cloud nine" type colony would be far easier to build and cost far less than this.
Because you don't need the radiation shielding, or the tank like construction, don't need to be careful to keep the air clean and not poisonous to humans, have oxygen in the air to breath, and can go outside of your house without a spacesuit.
And then nobody else will be interested in buying a "second hand" house in space - because it is probably almost on its last legs by then, like the ISS modules no longer fit for purpose after a few decades. So you can't even sell your home if you decide to move somewhere else.
So, in summary, with present day technology (unless we can change any of these things - which of course hopefully we might):
So - okay you could make a start on colonization with a few billionaires who are able to spend a billion dollars to make a house in space. You can get more houses if you have multi-billionaires (or wealthy sponsors) willing to sponsor houses for other people in space at a rate of a billion dollars a piece.
But it's not going to take off and become a place where your neighbour Joe Bloggs wants to go and live until it is
And at any rate not practical for more than a tiny proportion of the population of the Earth.
So - the current ideas for space colonization seem to follow this model -smallish habitats - not fully designed of course as no-one has yet demonstrated a closed system working habitat in space - but basically these low volume, immensely expensive tank construction type habitats - that will also need to be replaced after a few decades (at least don't see how they could last for centuries) - and all the other points in my list above. And not pleasant places to live in for your average Joe Bloggs, not like houses with windows you can open, places you can go out and breath the fresh air etc.
As such - I can only see it working for a few billionaires or heavily sponsored settlers - who also have to be space enthusiasts in a major way (or - they don't really appreciate what they are letting themselves in for - if so will soon become clear to everyone after the first few attempts).
So, I see a few ways around this, if we did want to colonize space
And 3D printers - well they will make a difference to some things. But will they build computer chips? Will they build components that are good for more than just temporary repairs of complex things like spacesuits? Will you be able to trust your life, in space, to intricate circuits printed on a 3D printer?
Maybe - but if so - then the situation on the Earth will be hugely changed also.
So - am not counting too much on that either.
But - Stanford Toruses - I can see those bringing down the cost, and being reasonably practical. But you still have the huge cost of building the torus in the first place.
Eventually though - a Stanford Torus - it's just a million tons - not so huge, about same mass as the Empire State Building. Once construction costs come down - and if it can be made easier to maintain in some way - could see that being affordable - just as you get people who build huge skyscrapers and then rent them out.
All the same you need a reason to be there. Will people really want to live in space rather than on the Earth? Seems very exciting to space enthusiasts now perhaps. But - once it is mundane and anyone can fly into space - as easily as they can fly to another country? And - a time when just about everyone has taken at least one flight to the Moon and had a go at jumping around on the surface etc?
Our blue Earth may then seem to be the luxury place where everyone wants to live, and space - a place where you spend some time - but just because you have to live there, e.g. for space mining, and for one reason and another you can't live on the Earth.
Some will find it a cool place to live. Some like to live at the S. Pole through the arctic winter. But - for most - they will prefer the more comfortable and easier to live on Earth :).
If we do get to Stanford Torus type habitats though - they could be as pleasant and easy to live as the Earth - possibly. Not so sure as all that - I will believe it more easily when I see it (if I see it), but it might happen.
Just sharing a few thoughts here. You may see things differently and that's just fine :).
Personally also I'm concerned about whether we should colonize space at all.
Before we do this, I personally would need some answers to the questions
For these reasons -I think we are not yet at the point in our civilization where we should be even thinking about colonization.
We need to find out more, do lots of exploration, temporary settlements fine, sending humans to outer solar system if we can etc. Taking care to act in a reversible way. So don't start anything in the solar system that we can't undo, especially not introduce life to planets where it can reproduce and never be removed again.
Then - if we can stay stable, and civilized, and peaceful on the Earth - or find some way to be really sure that we will be a long term stable, civilized and peaceful civilization in space - then - we should just wait. Explore, find out lots, set up small settlements and outposts like those in Antarctica.
But just not feel any hurry. There is no natural disaster headed our way to make us extinct - not yet - not for a few hundred million years when the seas boil dry. Asteroids won't make us extinct, though they can give us a difficult time - but by learning to deal with them, we can come together and work more as a planet as a whole.
There are lots of things going wrong, but also lots of things going right. I can see the good things winning out eventually. But not by going into space and colonizing. To me - that seems likely to make things worse. But going into space and exploring - that seems likely to have huge benefits so long as it is done carefully and responsibly.
After we've been an advanced technological civilization for a few centuries, we can start to think about taking on thousand year and even eventually million year projects. Maybe our lifetimes by then will also be thousands of years long.
I must say - I'm no economist. So not trying to present a financial model here of what would happen. Just using the costs as a way to talk about how difficult / easy it might be to live in space.
So anyway - that's how I see things, putting a personal view here. Any thoughts in all this interested what you have to say!
It's a bit like solar photovoltaic panels. For as long as solar panels were a far more expensive way of generating electricity - even if you were green - unless you were very wealthy, you didn't have solar photovoltaic panels. Now the cost has gone down, many have them. Make them cheap enough - and you don't need to find a way to pay for huge numbers of solar panels for everyone in the planet - they will buy them for themselves. So then "the cost of making sure everyone has solar panels" - is kind of irrelevant. What matters is the cost for an individual and how that compares with their other options.
As it is now, any habitat in space has to contain ten tons or so per square meter outwards pressure. So - basically talking about a tank type construction, but your buildings far more expensive than tanks, and stronger than them.
It also has to have cosmic radiation shielding to protect you - so that's about 4.5 tons per square meter shielding on the outside. And few windows - those are hard to build in space conditions - and if you are living there long term - you want the whole thing shielded if possible - will probably have view-screens rather than windows.
And - as well as that - needs some way to generate your air from ice. And some way of making a circulation system to get rid of poisonous gases. We don't realize it - but houses have to be ventilated to stay healthy, okay. But now imagine your house is totally airtight, not even air can get in or out?
That is - unless we can sort out closed systems using natural methods such as plants, trees etc - that would make this part far easier.
So depends. If we can get that to work, this bit is far easier.
But using present day technology, in space stations, totally air tight, you'd get a build up of all sorts of poisonous gases such as methane, hydrogen sulfide etc. And you have to keep scrubbing the CO2 out of the air because that is poisonous for humans, even when there is enough oxygen to breathe. And harmful microbes also build up in space habitats - they keep the air of the ISS very dry to reduce the build up of microbes - and still have to filter them out as well.
And either way, you have to grow all your food - not in open fields as we do here on Earth - but always in greenhouses. And those greenhouses also have to contain tons of outward pressure. And probably need artificial lighting as well.
And have to deal with the build up of wastes - a human generates tons of waste every year - what do you do with it all? Can you recycle it? If so how? Can your plants and ecosystem cope with human wastes? Or do you use machines for those?
And add to that - that any time you go outside your habitat you need to wear a spacesuit. And that spacesuit - it's not just like fancy clothes you wear like a raincoat. It's an immensely complex bit of hardware. Basically it is a mini spaceship in its own right, able to contain an environment inside of it that a human can live in - and with a thin covering easily breached - and you die within seconds if you have an accident. And long term spent outside your habitat and you increase your lifetime risk of cancer from cosmic radiation. So people aren't gong to want to do that. Most will keep indoors if they possibly can - just as they are cautious about getting skin cancer here on the Earth.
In any case - it's very clumsy. So - you can't just go out with a shovel, chances are you do most of your work from inside the shielded habitat driving machines around via telepresence.
And - in the stressful environment of space - I mean mechanically stressful - your house, built like a tank but more so - it's still not going to last that long. Not like the centuries with minor repairs of a house on the Earth. The reason is because it goes through huge temperature fluctuations every time part of it goes into shadow, and long term, little cracks build up and destroy it.
So, chances are, more like a few decades, like the design life of the ISS - then probably you have to build a new house again.
Clearly - this is nowhere close to competing with the building costs of a house on the Earth. Or of starting up a new farm on the Earth - even if it is in a desert and you have to cover all of the acres of your farm with greenhouses - and supply them with sea water piped from the sea - and then back again - evaporating to create water and cool down your greenhouses at the same time - as in the sea water greenhouses project - still - you are talking about just a fraction of the cost of a space home.
So - how much is a house like that going to cost? Surely, even when the prices go right down, even if it was as easy to build in space as it is to build on the Earth, it would still cost, like a hundred or a thousand times more than the same house on the Earth don't you think?
Even the same house + fields to grow crops constructed on an Earth desert, or floating in the sea, or floating in the upper atmosphere in a "cloud nine" type colony would be far easier to build and cost far less than this.
Because you don't need the radiation shielding, or the tank like construction, don't need to be careful to keep the air clean and not poisonous to humans, have oxygen in the air to breath, and can go outside of your house without a spacesuit.
And then nobody else will be interested in buying a "second hand" house in space - because it is probably almost on its last legs by then, like the ISS modules no longer fit for purpose after a few decades. So you can't even sell your home if you decide to move somewhere else.
So, in summary, with present day technology (unless we can change any of these things - which of course hopefully we might):
- Need to cover with 4.5 tons per square meter of radiation shielding
- Need to withstand 10 tons (approx) outwards pressure, house built like a tank
- Your home is probably built to last at most a few decades, then you have to discard it, salvage what you can from it - and build a new one
- Need to provide and maintain spacesuits for everyone
- Need for expensive, vacuum rated machinery (probably controlled by telerobotics) for any heavy lifting
- Need to get replacements and repairs for anything complex damaged or that degrades from Earth at huge expense.
- Need for enclosed "greenhouses", probably spherical, able to withstand tons of outwards pressure, for any crops
- Need to remove poisonous gases continuously and scrub CO2 continuously etc
- Need to make your own oxygen
- Need to dispose of tons of waste per person per year in some way.
So - okay you could make a start on colonization with a few billionaires who are able to spend a billion dollars to make a house in space. You can get more houses if you have multi-billionaires (or wealthy sponsors) willing to sponsor houses for other people in space at a rate of a billion dollars a piece.
But it's not going to take off and become a place where your neighbour Joe Bloggs wants to go and live until it is
- Much less expensive, comparable in price to a house on the EArth
- Pleasanter place to live
Some space enthusiasts are so keen - they are willing to sacrifice all comforts and basics and spend rest of their life struggling to stay alive - if needs to - just to be able to live in space rather than on the Earth - but most people are not like that. And I think myself - that once it is no longer exciting and new - but thought of as a bit like deciding to live in Alaska or Siberia - but far more expensive and harder than either of those - then nobody is going to want to go there for more than a short time unless they have some other reason.
And at any rate not practical for more than a tiny proportion of the population of the Earth.
So - the current ideas for space colonization seem to follow this model -smallish habitats - not fully designed of course as no-one has yet demonstrated a closed system working habitat in space - but basically these low volume, immensely expensive tank construction type habitats - that will also need to be replaced after a few decades (at least don't see how they could last for centuries) - and all the other points in my list above. And not pleasant places to live in for your average Joe Bloggs, not like houses with windows you can open, places you can go out and breath the fresh air etc.
As such - I can only see it working for a few billionaires or heavily sponsored settlers - who also have to be space enthusiasts in a major way (or - they don't really appreciate what they are letting themselves in for - if so will soon become clear to everyone after the first few attempts).
So, I see a few ways around this, if we did want to colonize space
- The colonies actually benefit the Earth - that was the idea for the original Stanford Torus - that they would build solar satellites to benefit the Earth - and are other ways it can happen e.g. space mining. But this has to be a real benefit. If we can make the solar satellites as easily remotely, or autonomously, not going to work out long term.
- You build really huge colonies - and somehow arrange that they are low maintenance. E.g. - maybe - though I wouldn't like to say for sure - a huge million ton Stanford Torus - with all the 4.5 tons per square meter shielding - once built would be low enough maintenance so that - spread over its 10,000 residents - it lets them build houses at more or less reasonable prices inside of it. You have a tax of maybe say $10,000 a year or whatever towards upkeep of the habitat per person - for 10,000 residents, that's $100 million a year. Is that enough to keep it going? Or is it more like $billion a year so $100,000 a year per resident (I mean in todays prices) - or $10 billion a year, so a million dollars per resident? - the exact figures here could make a huge difference to how viable it is.
The problem here is - who will find all that upfront money to build a big colony. I'm not sure of an up to date costing, I think the Stanford Torus was of the order of $100 billions (can't remember the exact number) - that's in 1970s money - so would imagine of the order of $trillions per habitat in today's money. Might be less. Might be as low as a few hundred billion dollars.
The Stanford Torus costs less than you expect - because the idea is to send a small bulldozer to the Moon - and a mass driver - and most of the heavy work "hauling" the million tons of cosmic radiation shielding to cover the habitat is done by the bulldozer loading materials onto the mass driver and launching it to the place where it is built. So that part - which you might at first think insurmountable - basically costs the Earth very little.
If it is, say, $1 trillion, the US could find that with half their military budget for a little over three years - so if there was a really good reason to build one, the money could be found, somehow or other, by one country, or several countries sharing the cost. But is there a good reason? Something that would pay it back quickly or some other reason?
And 3D printers - well they will make a difference to some things. But will they build computer chips? Will they build components that are good for more than just temporary repairs of complex things like spacesuits? Will you be able to trust your life, in space, to intricate circuits printed on a 3D printer?
Maybe - but if so - then the situation on the Earth will be hugely changed also.
So - am not counting too much on that either.
But - Stanford Toruses - I can see those bringing down the cost, and being reasonably practical. But you still have the huge cost of building the torus in the first place.
Eventually though - a Stanford Torus - it's just a million tons - not so huge, about same mass as the Empire State Building. Once construction costs come down - and if it can be made easier to maintain in some way - could see that being affordable - just as you get people who build huge skyscrapers and then rent them out.
All the same you need a reason to be there. Will people really want to live in space rather than on the Earth? Seems very exciting to space enthusiasts now perhaps. But - once it is mundane and anyone can fly into space - as easily as they can fly to another country? And - a time when just about everyone has taken at least one flight to the Moon and had a go at jumping around on the surface etc?
Our blue Earth may then seem to be the luxury place where everyone wants to live, and space - a place where you spend some time - but just because you have to live there, e.g. for space mining, and for one reason and another you can't live on the Earth.
Some will find it a cool place to live. Some like to live at the S. Pole through the arctic winter. But - for most - they will prefer the more comfortable and easier to live on Earth :).
If we do get to Stanford Torus type habitats though - they could be as pleasant and easy to live as the Earth - possibly. Not so sure as all that - I will believe it more easily when I see it (if I see it), but it might happen.
Just sharing a few thoughts here. You may see things differently and that's just fine :).
Personally also I'm concerned about whether we should colonize space at all.
Before we do this, I personally would need some answers to the questions
- Can humans be peaceful in space - and leave our wars and terrorism and financial disasters and such like behind when we colonize space?
- Or will all our problems and issues be written larger - with huger financial swings, entire countries on the Earth running up massive unexpected debts overnight, warfare, terrorism, and dictators and people with aims we find strange, even crazy - with all the technology of a space colony? Would we just export our problems and issues on an even larger scale into space and make things far worse (long term I mean not the current somewhat idealistic colonists, at least not right away - but as you get to thousands, then tens of thousands, hundreds of thousands and millions living in space)?
- Can humans be content to stay in our solar system? If not - what happens to a galaxy filled with humans - and not just us - but our descendants, and the things they make including cyborgs, self replicating machines, ability probably to even remake entire planets with a simple command to your personal computer assistant machine to start reproducing an appropriate self replicating machine to do the job.
Can that be a safe galaxy - safe for other ETS and also safe for us? Or would our descendants and constructions a few tens of generations in the future become the ET monsters and Earth invaders of Sci. Fi.
For these reasons -I think we are not yet at the point in our civilization where we should be even thinking about colonization.
We need to find out more, do lots of exploration, temporary settlements fine, sending humans to outer solar system if we can etc. Taking care to act in a reversible way. So don't start anything in the solar system that we can't undo, especially not introduce life to planets where it can reproduce and never be removed again.
Then - if we can stay stable, and civilized, and peaceful on the Earth - or find some way to be really sure that we will be a long term stable, civilized and peaceful civilization in space - then - we should just wait. Explore, find out lots, set up small settlements and outposts like those in Antarctica.
But just not feel any hurry. There is no natural disaster headed our way to make us extinct - not yet - not for a few hundred million years when the seas boil dry. Asteroids won't make us extinct, though they can give us a difficult time - but by learning to deal with them, we can come together and work more as a planet as a whole.
There are lots of things going wrong, but also lots of things going right. I can see the good things winning out eventually. But not by going into space and colonizing. To me - that seems likely to make things worse. But going into space and exploring - that seems likely to have huge benefits so long as it is done carefully and responsibly.
After we've been an advanced technological civilization for a few centuries, we can start to think about taking on thousand year and even eventually million year projects. Maybe our lifetimes by then will also be thousands of years long.
I must say - I'm no economist. So not trying to present a financial model here of what would happen. Just using the costs as a way to talk about how difficult / easy it might be to live in space.
So anyway - that's how I see things, putting a personal view here. Any thoughts in all this interested what you have to say!
About the Author
Robert Walker
Writer of articles on Mars and Space issues - Software Developer of Tune Smithy, Bounce Metronome etc.Studied at Wolfson College, Oxford
Lives in Isle of Mull
4.8m answer views110.4k this month
Top Writer2017, 2016, and 2015
Published WriterHuffPost, Slate, and 4 moreHuffPost, Slate, Forbes, Newsweek, Business Insider, and Science 2.0