Extra-planetary colonization

[Eclipse Now]

Woah! 600k diameter! Now you're talking! But do you really think we have to settle for 1/4 g? Surely that's not going to be good for our health? The premise of terraforming Mars was relying on lots of future tech for the terraforming, dealing with medical issues of low G, etc. The premise of a torus was to try and make a colony that would be more suited to us.

 

But hey, 600k! If you're talking that big then forget my exponential ponderings above. It's going to take generations to build something like that. The benefit is that once a significant torus of this size can be parked in somewhere with access to the asteroid fields or a gas giant with a handy moon nearby, then maybe they could just allocate a small percent of their work to building solar power satellites for Earth and shooting them into our orbit, and even crashing the occasional ice asteroid into Mars, as a means of funding some trade.

[Moontanman]

Woah! 600k diameter! Now you're talking! But do you really think we have to settle for 1/4 g? Surely that's not going to be good for our health? The premise of terraforming Mars was relying on lots of future tech for the terraforming, dealing with medical issues of low G, etc. The premise of a torus was to try and make a colony that would be more suited to us.

 

But hey, 600k! If you're talking that big then forget my exponential ponderings above. It's going to take generations to build something like that. The benefit is that once a significant torus of this size can be parked in somewhere with access to the asteroid fields or a gas giant with a handy moon nearby, then maybe they could just allocate a small percent of their work to building solar power satellites for Earth and shooting them into our orbit, and even crashing the occasional ice asteroid into Mars, as a means of funding some trade.

 

600 kilometers is just a wild guess really, I'm sure someone here with real engineering skills can correct me but the gravity is a real deal breaker, the less the gravity the bigger it can be.

 

I am assuming that humans do not need full G to be healthy. If all colonies are built to 1/4 gee then there should be no problem going from one to another. I doubt very much if humans will need one gee to be healthy.

 

Building this sort of thing should be relatively easy with robot construction. Once the facilities are built programmable robots should be able to build it on an assembly line, in 0 gee such construction work should be a piece of cake.

 

Think of building a nuclear aircraft carrier, how long would it take one man to build it? millions of years? But thousands of men can cut the time table back quite a bit. Robots should allow it to go even faster.

 

In the book Titan, Gaea was a biological machine, the 1300 kilometer torus actually grew so who knows what might be possible once we get out there and try.

[CraigD]

But do we have a technology for this super-long super-strong superconductor thingy gizmo, or is this more in the same league as space elevators?

Electrodynamic tether power generation and propulsion, while far from a proven technology – only a few have yet actually been flown, and all were either only partial system tests, or failed fairly quickly for unexpected reasons – is much more near-term feasible than space elevators. It doesn’t need superconducting or super-strong material, and can be scaled from anything from a few hundred meters scale to maintain the orbit of a small satellite using only electricity from, say, its solar power panels, to the big generators I describe in post 1.

 

The main limitation of ED tethers is that they only work in magnetic fields on the order of as strong as Earth’s, so will work only around Earth, the giant planets, or close to the Sun. The few “teething problems” that have appeared to date in the technology from the few test flights of it appear to me to fall into 3 main categories: avoiding snapping the tether when deploying it due to reel problems or unexpected “shimmies”; avoiding insulation failures; and managing voltage fluctuations due to irregularities in the planetary magnetic field.

 

The second of these practical problems may prove the most troublesome, long-term. Fundimentally, ED tethers work – that is, produce net acceleration when an electric current is applied, or an electric current when accelerated – because the electric circuit they create is half in a conductor attached to some vehicle (satellite, giant power moon, etc), and half in barely noticeable plasma not attached to the vehicle. This is much like delivering a high-power electric current underwater with a waterproof insulated cable containing a single wire. A small failure in the insulation can result in the tether’s very high voltage forming a “short” circuit with very little resistance, quickly vaporizing the tether at the point of insulation failure. This is believed by many to have been what severed the planned 20.7 km tether deployed as the primary mission objective of the 19th Space Shuttle Columbia mission in 1996.

 

On to a different subject...

who thinks we have the technology to build a decent sized torus today?

I think that parts of the technology necessary to build the various big centrifuge spacecraft called such things as a Stanford Torus have long been available, while others still are not.

 

In particular, the “bridge building engineering” of building such big, spinning vehicle, is not in my estimation that great a challenge, using either modern of future non-metal materials, or 19th-centruy ones like steel, concrete, and glass. Suspending even a colossal weight with pretty low-tech materials over modest "vertical" distances of a kilometer or two, isn’t, in my estimation, that hard a challenge, or even as hard as 19th-21st century bridge building, which doesn’t enjoy Torus-building's luxury of always having a load-bearing attachment point directly “overhead”, so must have complicate trusses, arches, and suspension schemes.

 

I suspect we overestimate how pretty tori may actually be. Though most artist renderings show huge cable-free volumes of air and vacuum, elegantly angled suspension cables, and beautifully curved stressed skins, I suspect uglier schemes with more closely-spaced cables may be better. Rather than these dreamed-of Frank Lloyd Wright/Werner Von Braun masterpieces :hihi:, what’s actually built may be more aesthetically akin to strip-mall parking garages. :)

 

The other major technology needed to build a torus, space manufacturing and construction, is at present almost totally untried, and only vaguely conceived. The reasonably forseeable cost, resource requirements, and environmental impact of sending the huge masses of materials needed for a decent-sized torus up to it from the Earth’s surface almost certainly demands that the raw materials be collected and manufactured into construction-grade materials in space. So before you can begin the actual construction of a torus, you must have spacecraft that travel to, collect, refine, and return with huge amount of material from, say, asteroids.

 

We’ve barely – and only by the grace of large parts of heroic ingenuity, luck, and not-quite-home-yet – managed a single small sample-retrieval mission to an asteroid – JAXA’s Hayabusa – and until its planned crash-landing next month, it’s anyone’s guess if that 7-year-long mission actually managed to get any asteroid dust into its sample containers. The technology to actually mine asteroids or low-gravity moons, which I think is critical to building extra-planetary habitats, is barely in its infancy.

[Moontanman]

CraigD, I agree that construction is the key here but I don't understand what you mean by going and getting materials and bringing them back.

 

I think you would take your manufacturing equipment to the resources not bring your resources to the manufacturing equipment. The Trojan asteroids of Jupiter for instance probably contain all the materials you need including carbon oxygen and nitrogen. Building you tori there would make more sense that arbitrarily setting up construction someplace else.

 

The tori would be free to move all over the solar system in slow orbits once they were built.

[Moontanman]

I think I said it before but it's worth going into some detail. The Titans in the books by John Varley were examples of technology out of control. The Titans grew from seeds that traveled across the galaxy from star to star.

 

The Titans eject the steerable seeds at the escape velocity of the sun and direct them toward other stars, millions of years in transit they land on a small moon or kuiper belt type body and grow into Titans, they people the inside of themselves with various beings thought to be descendants of the now long forgotten designers.

 

In the book there were several Titans in our solar system, mostly around Neptune and Uranus (:naughty:) but Gaea, in orbit around Saturn, was the largest, "Fairest of the Fair" and 3,000,000 years old.

[Eclipse Now]

Hi Craig D

 

I'm glad you mentioned the technical challenges of mining asteroids as it reminded me to ask about more short term goals, even if that remains the long term goal. Rather than mining asteroids in the shorter term, experimental phase, what about a moon base with maglev rail gun as one option for kick starting construction of a much closer Lagrange torus?

 

Hi Moontanman

Building this sort of thing should be relatively easy with robot construction. Once the facilities are built programmable robots should be able to build it on an assembly line, in 0 gee such construction work should be a piece of cake.

 

Think of building a nuclear aircraft carrier, how long would it take one man to build it? millions of years? But thousands of men can cut the time table back quite a bit. Robots should allow it to go even faster.

 

In the book Titan, Gaea was a biological machine, the 1300 kilometer torus actually grew so who knows what might be possible once we get out there and try.

 

 

Yes! This is the stuff that I love... speculating on what might be possible just a few tech upgrades out from where we are today. Those Varley novels sound impressive! I'd love to read an author of similar scope who wrote with today's nano-tech, biotech, and information technology paradigms in mind.

 

So maybe after our hypothetical moon-base-constructed Lagrange torus proves a hit, something else has occured back on Earth that could have implications for space travel. I'm thinking of the end of concentrated ore bodies, or 'peak metals'. Most concentrated ore bodies are expected to be exhausted in the lifetime of babies born today (based on 2% annual growth over the next 70 years, according to Lester Brown).

 

So humanity would then be tempted to develop unimaginably large mining gear for gathering all the low grade ores on Earth as we learn to chew through the low concentrations of metals in the continental bedrock and ordinary dirt to get the materials we need.

 

This slow going, environmentally destructive process could provoke mankind to look closer at the asteroids and retrofit some of the larger mining equipment for space. It could also spawn a new era of materials sciences and nano-tech that might also have great potential for developing our new homes in space.

 

Truly huge asteroid munching robots are imaginable if they are manufactured on the moon and rail-gunned into a Lagrange point piece by piece. There they are assembled and eventually flown out to the asteroid fields. They could be either manned, run by remote, or even AI, if AI turns out to be doable.

 

Then these leviathans of space munch through the asteroid fields, 'excreting' all sorts of useful minerals and carbon nanotubes and any other super-materials we've developed by then.

 

(This image is not quite what I had in mind, but is pretty cool anyway. From a gothic-horror FPS game called "Dead Space").

 

They can then shoot various payloads back to Earth for orbit (such as raw materials for another Lagrange station, space based solar power, communications satellites, etc), or self-aiming blocks of raw materials (steel, titanium, whatever) wrapped in re-entry shields and parachutes and aimed at the appropriate desert.

 

An economy finally develops in space, and who knows where all this could head?

 

Ahhh, exponential growth, here we come! (This time in a good way that's strangely comforting to my many Malthusian concerns.)

[kvraghavaiah]

Earth is the only home to us.

 

After developing supercomputers, nuclear bombs, genetic engineering, high technologies; people started to have over confidence in their extreme fantasies.

 

Man, who is not able to manage the best home properly (infact damaging with pollution and environmental imbalancing activities) is dreaming about building a new home, which is absolutely out of his scope.

 

Can you imagine living on these extraterrestrial environments? it is not natural. Did you ever hear about or notice anything that lives long against naturality?

 

Or man should be able to build another earth like nature for him in the extra terristry. Man is in no way capable of it.

[Tormod]

Earth is the only home to us....

 

Why? Apart from strawman arguments about "not being able to take care of our planet". Seriously, why shouldn't we colonize space?

[kvraghavaiah]

Why? Apart from strawman arguments about "not being able to take care of our planet". Seriously, why shouldn't we colonize space?

 

We can if it is easy. When there is a good home that can be used happily, why to destroy it and then think about building a new one at a very huge cost. Ok, suppose earth ends naturally..so we have to inevitably build a new home..even then, it is not possible for us to build such a big environment for a sustained living.

[Boerseun]

1968: "We can't go to the moon. We could if it's easy, but it's not, you see. So we can't go."

 

Hell - it's 2010, and we still haven't been to the moon! I wish it was easy...

[Eclipse Now]

Interesting articles and conversation about food on a Moon or Mars colony, and some of the ancillary side-benefits. But it seems like a lot of electricity.

 

Efficient use of resources is just as important for hydroponic greenhouses anywhere on the globe, Giacomelli emphasized. "All that we learn from the life support system in the prototype lunar greenhouse can be applied right here on Earth," he added.

"On another planet, you need to minimize your labor, recycle all you can and operate as efficiently as possible," he said. "If I ask the manager of a hydroponic greenhouse in Willcox [Ariz.] what's most important, he or she will tell me those same things – recycle, minimize labor, minimize resource use."

 

Carbon dioxide is fed into the prototype greenhouse from pressurized tanks, but astronauts would provide CO2 at the lunar base just by breathing. Similarly, water for the plants would be extracted from astronaut urine, and the water-cooled electric lights might be replaced by fiber optic cable – essentially light pipes – which would channel sunlight from the surface to the plants underground.

 

The lunar greenhouse contains approximately 220 pounds of wet plant material that can provide 53 quarts of potable water and about three-quarters of a pound of oxygen during a 24-hour period, while consuming about 100 kilowatts of electricity and a pound of carbon dioxide

 

http://nextbigfuture.com/2010/09/robotic-hydroponic-greenhouse-for.html

[Moontanman]

1968: "We can't go to the moon. We could if it's easy, but it's not, you see. So we can't go."

 

Hell - it's 2010, and we still haven't been to the moon! I wish it was easy...

 

 

We didn't go to the moon?

[Boerseun]

We didn't go to the moon?

Unfortunately not. According to Kvraghavaiah is his series of depressingly negative posts above my last one, it's too difficult. So no, we couldn't have been to the moon. It's too, like, hard 'n stuff, like.

[Qfwfq]

Seriously, why shouldn't we colonize space?

What the heck will we do in our spare time? Play golf on mega courses?

[Moontanman]

I think it should be pointed out that these colonies do not need to be 600 kilometers across and 100 kilometers thick, I can see the possibility of tori being quite small and housing a few families or even just one. A torus 100 meters thick and 600 meters across could house many people and might be a bettor bet than huge tori...

[CraigD]

I think it should be pointed out that these colonies do not need to be 600 kilometers across and 100 kilometers thick, I can see the possibility of tori being quite small and housing a few families or even just one. A torus 100 meters thick and 600 meters across could house many people and might be a bettor bet than huge tori...

I agree, and will go further to suggest that even smaller space habitats – on the order of a 100 m² living surface, lifted and assembled using existing technology – are a even better bet that 180000 m² you suggest.

 

Rather than the torus or cylinder arrangement typically proposed for space colonies, a tethered module arrangement can reduce the difficulty of building the habitat from needs-not-yet-developed-generation-of-technology to similar to building the ISS.

 

As we’ve discussed intermittently in this and similar threads, the challenges of building a space colony are not limited to technical ones. Even the very small kind I suggest would, estimating based on the ISS experience, cost on the order of US$ 100,000,000,000. To gain such money, a credible business plan showing at least a near break-even return on investment must be made. In short, the space habitat/colony must make money for its investors. How to do this is, as the saying goes, the 165 billion dollar question.

 

Having mulled it over a lot, I’ve an idea (disclosure: I’m barely if at all qualified to plan a boat rental business, let alone a venture larger than the economies of most countries, but my lack of business education and experience doesn’t limit my idea-dreaming ability :)) – special needs geriatric living, AKA

A Space Retirement Home!

Space habitats, a superclass of space colonies, can be divided into 2 kinds: those with appreciable real or pseudo gravity, and those without. Every space habitat made to date – SkyLab, Mir, the ISS – have been of the 2nd, gravity-less kind. Although bungie cords and exercise machines allow some of the effects of weightlessness – primarily the loss of muscle and bone mass – to be countered, there are many detrimental effects that only a gravity-like force can counter. Even for young, well-trained people – astronauts – living on a space habitat of the 2nd kind literally makes you sick. Staying on one for more than a few years would likely kill you.

 

So a true space colony – a space habitat you live on, other than the occasional vacation, for decades or your whole life – must be of the 1st, gravity-endowed king. The only practical way to do this is by making some or most of the habitat a centrifuge, hence the rotating, torus, cylinder, or tethered module designs mentioned before.

 

How centrifugally-generated pseudo-gravity relates to old people is that, past a certain age and with various age-related medical conditions, full Earth gravity becomes increasingly unhealthy. Muscles and bones are injured by it, blood and other fluids puddle in the body’s low spots, the heart and blood vessels are strained and damaged by it. Falls become potentially deadly. Though various exercises, medicines, treatments and protective devices can aid in the body’s battle with gravity, the most straightforward adjustment – simply reducing its force – isn’t possible on the Earth’s surface.

 

If your gravity-like force is generated centrifugally, however, reducing it to less than the standard Earth surface constant is easy, even advantageous, as a lower centrifugal force reduces strain and hence required mass of the space habitat’s structure. Living in a space habitat could literally make an old person light on her or his feet again.

 

So my idea comes down pitching a super-expensive retirement home to super-rich (and, assuming wealthy and benevolent national healthcare systems, the very needy), a retirement home with a feature unmatchable by any on earth – reduced gravity – and the intangible attraction of being among the first true space dwellers.

 

Start with 2 modules offering about 10 rooms of about 10 m², common areas, support equipment and staff costing about $100 billion. Add modules as demand and investment increases.

 

This biz plan (keep in mind I’m about as unqualified to talk about business plans as they come :shrug: ) is a savings-fueled one – rich old people will invest in or pay rent that pays back investors using their savings. Hopefully, once established, the colony could host and provide services to money-making ventures, such as Moon and asteroid mining. :thumbs_up

 

Many numbers must be crunched to estimate if such a scheme is even remotely feasible, and if so, what the initial size and expected growth rate is. Fortunately, there appears to be not shortage of aging super-rich people on Earth, nor imminent hope of preventing the effects of aging that make low-gravity living attractive, so the main demand for a space retirement home seems to me likely to remain for decades to come.

[Moontanman]

The main reason I thought of the bigger torus idea has to do with being able to generate power to enclose the habitat in a protective magnetic filed to protect the people from particle radiation. The idea of a retirement home makes sense but the open area of the torus would be a good selling point. I can see an open are inside the torus looking like a natural forest with small lakes and streams and low gravity. 1/4 earth gravity seems like a good level, of course the moon might turn out to be easier for this purpose and it has 1/6 earth gravity. Retirement home, i like it, where can i sign up?