One thing many of these designs don't bring up is long-term growth. Is the plan to build it once and that's it? Boring, and too prone to failure if the project runs into trouble at any point in time.
What I'd prefer to see is a space construction that is continuous. Imagine a ring station, but one that is cellular in nature- lots of smaller modules that together form the huge station. This allows one to construct and add further modules over time, growing as needed.
The beauty of this design principle is that we could start today. Design the first iteration of these modules, with the intent to fit them into SpaceX's Starship (or whatever heavy rockets come next). Launch 10 or 20 of them, connect them, and spin them up to 1/5th gravity, something not too hard to do. Add modules in the centre of the ring that are zero-G, where zero-G things can be done- but allowing those who live on station to live in mild gravity at least.
All the while, you can dream big. You can plan for how this station goes from 10 or 20 small modules to thousands.
Connecting pressure vessels together is a challenge. Each vessel and each joint is a failure opportunity, and having to go through bulkhead doors all the time doesn't scale well beyond mission crews. Plus you have to get the location of those doors right during initial planning.
For modularity it might make more sense to use nesting. A building inside a building has no seams. Doors only need footpaths between them, not hard structures. The inner building can be used for shelter in case of an accident, and can be run at higher pressures than it could in hard vacuum.
In the tinker toy model you would tend to have to keep repurposing buildings because while the size may be appropriate, the older structures may get pushed farther and farther from the center of the action, rather than staying in the center of the action.
I'm not getting the nesting argument here. At least in the early days, a window to space will be a key selling feature. That means that the surfaces will have greater value, like with skyscrapers, but worse. Worse because pressurization demands that surfaces bulge out to contain the atmosphere. So while a large sphere might be the best engineering solution, funny shapes held together by weird superstructures might be the most profitable option.
When we get into the more utilitarian phase of space development, then I think you would want something like shipyards where there really is a big micrometeorite shield (yes, as a sphere) with the inside filled with scaffolding. Robots scoot around do work with old and new hardware.
If you think about nesting ROTATING structure inside of other pressure-envelope structures, then you're getting into some really crazy stuff. Are there designs that might make sense? Maybe, I don't know, I guess I wrote a blog about it
I think you're doing a lot of math there to determine pressure and the fact is that pressure in a space station is going to be dictated entirely by biology - partial pressure of oxygen, nitrogen, and carbon dioxide for mammal metabolism first, and comfort and plant metabolism later on. By the time logistics of managing or building out a real habitat, you're in a ±5psi range. Anything outside of that died on the design room floor.
Windows are at a huge premium on cruise ships. It'll be much worse on space ships. But it's possible that inside windows will eventually look out onto something more interesting than the black void of space, so an inside window may be preferable. One of the reasons we look out the window in a car or on a boat is to establish the horizon and fight motion sickness. If you look 'outside' of a rotating space station - especially a rotating space station orbiting a planet or moon - you'll head rapidly in the exact opposite direction.
Even cruise ships tend not to hand underwater window, despite how desirable they might be. For the same reason, I doubt a space-station will have privately owned windows.
They're not really desirable on cruise ships at the end of the day. They gunk up quick and don't really have a great view even clean since you're either in harbor with probably silty water, or at speed in which case it's just fairly dark turbulent bubbles that you can see.
You could build rings around rings. A couple of the designs on that page have multiple 'floors' in the same ring. I suppose those could be built incrementally in either direction (stacking new rings, or adding another floor to an existing one).
I think my train of thought makes a bit more sense for moon and asteroid bases rather than free-floating orbital structures. And asteroid bases - on the right asteroids - are probably going to house most of the people.
The ISS design definitely doesn't scale up. Everything off axis is a lever arm and the bigger you make it the more the whole thing tries to twist itself apart.
I find it interesting that so many people claim spinning stuff up to create artificial gravity in space is "not too hard to do" and yet it has never been attempted, for a series of pretty compelling reasons. Everything is hard in space!
The big obstacle for spinning artificial gravity is that it won't really work on a small spacestation. It has been not tried because we never had the option of a so large station where it would make sense to try - I'm not saying that it's not hard, however, the fact that we haven't attempted it is not evidence that it's hard, it's fully explained by the needs and restrictions of our size-limited spacestations like ISS for which each module is limited to a 4.5 meter tube because of launch vehicle limitations.
Another reason why it's not done is because one of the reasons why we have a space station is to do microgravity experiments, and having artificial gravity only hurts that.
There was a plan to have a 'spinning module' on the ISS, but NASA cancelled it. NASA has never really supported artificial gravity, likely because none of the NASA Centers is really focused on it.
> likely because none of the NASA Centers is really focused on it.
That's what I thought until I started looking into it. The module has actually been built (several versions in fact), but never completed and launched.
It turned out during tests and simulations that the station's structural integrity was at risk and so it was decided not to attach a centrifuge to it.
Whether these concerns were warranted I cannot say, but engineers at NASA deemed it too risky to try.
I'm wondering if aiming for less than 1G of artificial gravity would be sufficient to counter the ill effects of zero gravity environments? If you could opt for, say 0.3g, then the required speed would be greatly reduced.
You're not wrong. But I feel that like most things, it's only hard because it hasn't been tried. Once we've done it a few times, it's routine. That's human nature.
We've also done some experiments already. There was, I believe, a Mercury mission where they spun the ship up. If I recall, it didn't go super well. But hey, we've had 50+ years to think of how to do it bette!
It’s done all the time on Station inside machinery. We also can easily making spinning rooms on Earth. merrygorounds are playground equipment for children.
It’s don’t commonly on Earth. Most of the point of LEO space stations is to study microgravity so you wouldn’t even want it.
It is indeed pretty easy, but annoying to do for technical reasons (rotating joints, etc). Easier not to.
It would require the building of a large space structure, which has never been done (even the ISS is not that large). For that, we'd need to get materials into space cheaper, or even mine/refine/manufacture materials off-earth.
The first thing that comes to my mind is that you either have to commit to have the entire habitable portion of a station be rotating, or you have to have some kind of rotating joint that connects the rotating and non-rotating parts of the station. That joint has to not leak air and be very reliable (if it seized up, the station could tear itself apart from the sudden torque).
Having the whole habitable part of the station rotate may be fine most of the time, but it makes docking with ships more complicated. If the ship can't be spun, then you can either use some kind of rotating docking collar (which doesn't have to be perfectly airtight if it's only used once in awhile, but it still has to be pretty good) or you have put on a suit and do a spacewalk just to move things back and forth between the station and the ship which sounds kind of inconvenient.
(I guess there's actually another solution which is to stop the station spin whenever docking with a ship. That costs energy and/or reaction mass, though, and you'd have to deal with whatever disruption switching to zero-gravity brings.)
I can see why they might not have wanted to deal with this for ISS, but maybe for a bigger/more ambitious space habitat we'll want to do it.
Regarding your idea of stopping the station rotation: a simple way to do it would be to spin a flywheel contained inside the station. It wouldn't need to be very heavy if it spins very fast.
Another possibility is to have the docking station completely disconnected from the outer ring atmosphere, and to use small "elevators cabins" attached to robotic arms to go from the ships to the rings and vice-versa.
Speaking of "really huge" - Culture Orbitals are about the ideal: ~3,000,000 kilometres across, 1g at surface and rotation time of 24 hours so no need to stuff like the shadow squares of Ringworlds.
Sadly, they do rather require "magical" technology....
From a radius of ~300m onward you'll see green lights (= good for people) for all considered parameters. RPM drops from 1.7 to 0.5 for a radius of 3000m.
I've always been curious on this question because I don't have any physics background.
If you made something like a gravitron ride on the moon, would it take a slower rotation speed to reach perceived 1g than if you spun up a ring station in orbit? This calculator makes it seem like you could get pretty close to 1g with just a bullet train running on a 3.14 kilometer loop.
It seems like the main thing stopping earth trains from being faster is that most of our tracks were built a really long time ago and it's not worth the effort replacing them, but if metal is readily available and you're laying new track already, designing for ~300km/hr wouldn't be that much of a stretch no?
Yes, a little. In freefall, such as on orbit, you need 1 gravity of centripetal acceleration. a = v²/r; v = √(ar); if we assume a 3-meter radius (roughly Gravitron size) we need about 5.42 m/s tangential velocity to get one gee. The moon's gravitational acceleration is 1.62 m/s/s; to find the centripetal acceleration needed to get a Pythagorean sum of one gee, we take √((9.81 m/s/s)² - (1.62 m/s/s)²) = 9.67 m/s/s. That means that now our √(ar) tangential velocity is just 5.38 m/s, which is less than 5.42 m/s. Does that help?
The main thing stopping earth trains from being faster is politics, not engineering. Trains have been occasionally going over 300 km/h since 01955, decades before maglev. The Shanghai Maglev Train has been running at 430 km/hr since 02004. The Euroduplex regularly runs 320 km/hr on regular 1435mm standard-gauge rails and reached almost 575 km/hr in a test in 02007. 300 km/hr trains have been in regular service since 01989. There are several other train lines that run over 300 km/hr, in Taiwan, PRC, France, Belgium, Saudi Arabia, Japan, Germany, the UK, the Netherlands, Italy, Spain, Korea, and Switzerland. Soon India and the US will join them.
The big advantage of maglev is actually not smoothness or absolute speed but acceleration and deceleration.
4 rpm is about as fast as you can spin to avoid vertigo when turning your head. So for 1g that requires a diameter of 56 meters (about the size of the leaning tower of Pisa), which is big.
Other challenges include how to spin it up (and down) safely, how to dock with non-spinning things, how to deal with changes in mass distribution, and how to put thrusters on it for use when it's spinning. None of these is impossible, but together they create a serious engineering problem, and the size of the whole thing is ultimately the dealbreaker.
The ISS is 109m end to end so a 56 meter diameter isn't an impossible dream. I've toyed around with a design that uses basically a shell around Starship that would be bolted together in orbit to form the station. I was aiming for 2 RPM however.
Docking would be via a central hub. Ships would have to match rotation to dock, but it shouldn't be too hard. My conclusion is that if the money and/or political will were there we could start doing this today, but the project would be hugely expensive (even with SpaceX cutting launch costs to a fraction of what they were only a few short years ago) and once you have it built it will be looking for a purpose. It would be cool for people to basically commute up to the central part (via elevator) to do zero-g research stuff, then commute back to the ring to live and avoid the various health problems with long term zero-g living like bone density loss.
You can even build a simple starter station that has only two segments on opposite sides of the central hub. This is less cool since you don't get the jogging path around the station. If stability is an issue you could also include a computer controlled mobile counterweight on the ends. I also had the concept of building it as a double hull with a layer of water between the inner and outer to reduce radiation flux and absorb micrometeorite impacts.
But in the end you are still talking about a hugely expensive project that solves problems that aren't all that bad yet. About the only way I could see this being built is if Elon decides to go all in on space and liquidates his fortune to build it. The instant some annoying bean counters ask the question "is this the best way to spend this money" the project is dead.
Basically, we would need to make something hundreds of meters in diameter to have any hope of a comfortable living situation. This is a huge amount of mass to get into space, which is notoriously expensive, but getting cheaper every year. Maybe one day we'll hit an inflection point where this is reasonable.
Put in 3RPM and it spits out a 100m radius. This is big for sure, but in the same order of magnitude of the ISS. If you are willing to live with only 0.5g instead of 1g you can slow it down to 2RPM at that size and be safely within human comfort limits.
That would give you a circumference of around 628m. That sounds like a lot, but if you could build it in 80m segments by bolting each segment to the outside of SpaceX Starship (which is 120m tall) that would take 8 launches to get the ring in orbit. Plus some more launches for the hub and spokes and panels and everything else of course. Still, 15-20 launches is not outside of the realm of the feasible. If there were the political will (or personal fortune) to build this it could be done.
Not necessarily. Andy Weir's 'Hail Mary Project' describes a way you can get the best of both worlds: don't make a full ring, but spin two objects separated by cables.
Split the initial station into two stations with a large number of cables connecting them securely. Now on your calculator, put in a 70m radius and a gravity of only 0.3g. All green dots.
But how do you get between the halves?" you ask? I think there's a simple answer to that: have cables complete the circle. A small car riding those cables can carry you around the radius. Then over time, you add more cells until the circle is complete!
If you give one half of the station twice the mass of the other, you can test out living in lunar gravity and Mars gravity at the same time. Maybe only one of those will turn out to be enough to stop bone loss. Maybe neither one. It would be better to know that before building a base.
The zipline would be trickier to make work, then. Probably you have a gadget that walks up the tether, and then you flip around and it walks down to the other end.
You don't even need to complete the ring so that you can start with a lot bigger radius. The larger the radius the less the weird gyroscopic effects when people turn their heads in certain directions and the closer it replicates earth's gravity. Then you can expand the ring by increasing the arc coverage.
Right, start with three cans, two of them swinging at ends of a cable, one at the hub with a docking port. Add onto that, two cans at a time, lowered from the hub; link them up to existing cans. When the ring is full, tada! Then, extend the center can out a ways, on the axis, and start over, nestling new cans honeycomb-wise. Or maybe give the next ring a bigger radius; each existing can gets a pair of basement cans.
Or, just extend everybody's cable a notch so there is room to shoehorn in the next pair of cans. As you add cans, the radius grows.
"Cans" is the only practical way to think of building a rotating station. Of course, the cans are really Starships, hanging by the nose. Passageways between cans are fabric tunnels. Each can has a mass on a column that is automatically raised and lowered as people and things move around, to maintain rotational stability, and keep the hub centered.
> Of course, the cans are really Starships, hanging by the nose.
Realistically, you'd want to keep re-using the expensive parts of the starship rather than park them in space, which makes me wonder what's the best way to re-use a starship while leaving cylindrical body sections in space?
You could have a Starship body with sections that are removable -- like maybe you have a 50 foot section that unbolts from the nose and the tail which you leave in space, while the nose and tail get re-connected and return to Earth as a shorter version of Starship. Or maybe you could just launch two Starships, and in space remove the engine from one and place it inside the other as cargo, so you land one complete starship and the extra engine, but leave one complete body in space.
I doubt it's possible to have a disembodied engine land itself using its own thrust without a lot of clever and novel engineering, but maybe it can land by parachute? Or use thrust to slow its re-entry so it doesn't overheat, then parachute the rest of the way?
I could imagine unbolting the Vacuum Raptors and stowing them before you hang the can. (Once you have enough Raptors, you can redeem them for a free can!) They get packed as cargo in one of the non-can Starships and landed for re-use.
Maybe you vent the tanks and open a hatch on top, and there is a stairway inside with floors, ductwork, and places to clip on lights and electric outlets. Probably you roll out insulation onto the walls so you don't burn yourself or get frozen-stuck if you touch them, depending on what is going on outside.
The rings should be modular to ease building and to aid in compartmentalization. However, adding to existing rings could be difficult in terms of planning or engineering, since you'll be changing the balance of the entire system and you'll probably want the module to be in a particular position.
If you instead make the rings "super-modules", you can connect as many as you like along a central axis of rotation. As long as the individual rings are balanced you're good to go. If they spin freely relative to each other, you could even build a super-modular ring in place and only spin it up after it is complete.
If you plan to add more rings you're going to run into the Dzhanibekov effect https://en.wikipedia.org/wiki/Tennis_racket_theorem, which was still a Soviet state secret at the time space habs were being imagined, and might have still been a secret when they filmed 2010. That station would have been wobbling like crazy.
I'm pretty sure that phenomenon even kills the https://en.wikipedia.org/wiki/O%27Neill_cylinder, especially once you introduce liquids and soil to the interior. It's likely that we have to spin the cigar along the long axis to keep from killing everyone, which would greatly reduce the usable surface area and screw up the artificial lighting situation.
I think you got that backwards; the long axis of an O'Neill cylinder is the principle axis, and the only one that would be stable. The second (unstable) and third (stable) would both be unsafe because the issue with contents shifting making them potentially switch rolls. But that was never the plan, so no great loss.
If I understand correctly, the first principal axis has the smallest moment of inertia and the greatest kinetic energy. Anything that can dissipate the kinetic energy (like soil or water generating heat) will cause the ship to not be able to maintain that rotation and in order to conserve angular momentum it will instead rotate around the other stable axis—the third principal axis or end-over-end—since that axis has the greatest moment of inertia and minimum kinetic energy.
Space travel is surprisingly cheap and easy if you don’t have to overcome a planetary gravity well to get anywhere. The plan for growth is to build space habitats for the people who are living in space and working in space to build, among other things, more space habitats.
Exactly, only op does not account, that some Russian[insert the one that at that point is at lowest development capability] module on joining would create space colony quakes and add other hazards... maybe even huge hole in the structure.
These pictures always make me smile for several reasons.
One, they had a significant impact on the science fiction that came after them. We see recapitulation of this imagery in a lot of '70s-'90s anime (less often in live action, which I attribute to cost to film it).
Two, I believe when we get anywhere near a technology level to try something like this, the result will look radically different. I'm reminded of the way that old depictions of the Earth from space rarely included the clouds, which are omnipresent and unavoidable when actually looking at the planet. Some things, a person just can't imagine until they're there.
Agreed on both points. I remember seeing some of these images back in the 70s when space colonies were first seriously proposed. The idea that I might live to see such things built was thrilling. But looking at these images now, they seem very naive. I suspect the reality of space colonies, should we ever build them, will be much less like an idyllic space suburb and more like a dense urban complex.
I think what space colonies end up looking like in reality depends entirely on the infrastructure we build.
If we’re stuck with rockets that either lift tiny payloads or are ludicrously expensive to launch (see SLS’ $2B-$4B estimated cost per launch), I think your predictions are right on the mark. In that situation building anything even remotely luxurious is not practical.
If we assume the existence of something like Starship+Superheavy as it’s currently planned, that starts to change. You’re still not going to see O’Neill cylinders, but simple ring stations with interiors nice enough to be resorts are within grasp.
To achieve things as fully as depicted in these images, extraction of resources and manufacturing in space will be necessary. Even with cheap superheavy launch, lifting all the required material to orbit isn’t a practical consideration. Achieving those prerequisites is helped quite a lot by Starship though, because it’s more than enough to bootstrap asteroid mining operations and the like.
The toroid colony image seems to make an appearance in the movie Interstellar as well.
Given the risk of random super high speed/energy collisions with space objects, I would wonder if a more resilliant craft shape might be based on something nested and self-simlar, literally, "bigger on the inside," or like a disconnected formation that isn't physically connected. An orbital craft in a relatively stable solar system that used a planet as a lower energy "mooring ball" might allow for simpler geometric craft forms, but there's probably a maximally optimal shape for deep space starfaring vehicles. (oumuamua was very oblong and cylindrical, which might be a hint).
The craft in Interstellar WAS a long cylinder, not toroidal. And I think it’s plenty resilient. The heaviest structure is on the outside, perhaps several meters thick. It’d take a pretty huge space rock, easily detectable with radar and almost on the order of something hazardous to the Earth, to puncture straight through 10 meters of rock shielding and steel structure.
I stand corrected, I had interpreted that Cooper Station was a toroid and not a cylinder. Indexing on not getting hit at all seems more plausible than being resiliant to impact, unless our eventual interstellar travel involves some kind of space distortion that avoids collisions with anything below a certain mass/energy. Mental reference for effects of impact was something like this: https://bigthink.com/hard-science/heres-the-damage-a-tiny-sp...
Oh sure for actual interstellar travel. I was thinking interplanetary speeds (~10km/s) not interstellar travel speeds (~30,000km/s). In the film, they’re cheating by using a wormhole so never travel at those near relativistic speeds.
If we do build 'space colonies' I'm not sure that they'll be that different. The main reason behind these designs is to use centrifuge force to create artificial gravity. So until and unless we do invent some real Sci-Fi artificial gravity this remains our best approach and so are these spinning designs.
I think we'll actually see more of similar designs, even if much smaller, e.g. in spacecrafts for human journeys beyond the Moon and, indeed, space stations.
Interestingly, many very recent Sci-Fi movies involving realistic-ish human space travel feature spacecrafts with spinning toroidal living quarters.
> One, they had a significant impact on the science fiction that came after them. We see recapitulation of this imagery in a lot of '70s-'90s anime (less often in live action, which I attribute to cost to film it).
Don't forget Gene Wolfe's marvelous The Book of the Long Sun!
I remember seeing some of these actual pictures in the late 70s, early 80s, they were very striking and mindblowing to me as a child, the idea of huge pieces of structure with lush green parks and farmland in space. They are really memorable and probably shaped a lot of peoples imaginations about what might be possible one day.
I had a kid's encyclopedia of science that had a section that featured these pictures, I must have spent hours staring at them, they were mesmerizing.
It's feels strange to look back and think how much the world has changed since I was a child in the 1980s, and yet how little it changed in the ways I thought it would.
I was thinking about these drawings yesterday when I saw the mockup of a ring made from 32 Starship fuselages. Welded end to end, 32 pieces would net a 1/4 mile diameter ring with a volume ~85x the ISS.
Elon estimates that the refueling procedure necessary for interplanetary starship missions would require 8 fuel tanker starship launches, but this could be cut in half if the tankers were stripped of the elements needed for reentry and landing.
I could see the economics working out to where it would make more sense to launch stripped down single use fuel tanker starships, and then sell the empty orbiting shells to someone interested in building in space.
The exterior structure is a fraction of what you need for a working station though. It is a limiting factor on size because traditionally the module needs to fit in a faring but doing that doesn't save much cost because you still have to haul up all the other equipment.
Exactly. Many reusable starships flights would be needed to ferry up all the trappings of a working station, while returning reusable elements like the engines from the now mothballed fuel tanker ships.
I just meant to point out that a stripped down starship would consist of 30+ tons of easily weldable steel pre-fabricated into a reinforced pressure vessel. Spacex's interplanetary goals would benefit from treating the tanker starships as expendable, and if someone was inclined to start building habitations similar to those depicted in the link, they could buy up the building-blocks for a song.
Nothing is easily weldable in space, and empty hulls aren't habitrail elements that you can connect into something useful (unless a lot of design goes into it up front). Even if the hulls were free, the cost of creating such a space station would be prohibitive.
Nothing is easy in space, but 304L SS is easier to weld than 2219 Al or Ti, the main structural metals on the ISS. Welding in space has been well studied by both NASA and Roscosmos. Most testing was done in the 60s and 70s in preparation for possible repairs due to high-velocity impacts. More reciently, testing has been focused on 3d printing via additive welding.
The main issue with welding in space is the lack of convection based cooling, which means the welds take longer to cool through conduction, which can result in a larger HAZ. Increasing the mass and heat capacity of the adjacent material greatly reduces this.
The lack of an atmosphere and contaminants makes space a near ideal welding environment.
The difficulty is on Earth you have a convenient stable mass to anchor your robot to while in space everything is unmoored and unstable if you start swinging around a robot arm.
exactly. there are no large masses in space let alone ones we can anchor things to. the country of canada tried to build a robot arm for space and they ran into this exact problem. seriously, if they would just consult smart people like us then maybe they could have saved themselves the trouble of launching silly robotic arms into literal orbit.
Oh no I totally didn't think of the most famous robot arm in space, one that moves slowly and carefully and was planned and designed to work with the single largest and heaviest thing we've ever assembled in orbit. My point was you can't just grab a generic industrial arm and sling it around it needs a lot of consideration on how to mount and move it, Canada arm moves quite slowly and carefully.
no, i think "welding is hard in space" is much more insightful. it is much better to make a broad and sweeping statement and then discard a bunch of important possibilities.
Yes, under certain circumstances. Two pieces of identical metal, with no surface coatings or oxides, will directly bond if placed in intimate contact. Done properly, the weld would be as strong as the metal. As Feynman put it, the atoms have no way of knowing they are in different pieces.
Similar results can be reliably recreated on earth. Ultrasonic welding rubs two pieces of metal together until the oxide breaks apart leaving pure metal to fuse. Explosive welding creates a plasma that strips off the oxide layer, and then propels the metals into each other. This method has the benefit of bonding dissimilar metals, and usually produces bonds that are as strong as the weakest metal.
It's not perfect and you wouldn't want to trust it for a habitat. It requires the surfaces to be pretty meticulously clean and it's not as strong as traditional welds.
Looking at these images, I can't help but feel that any real space colony like this will be like Singapore on steroids.
For all its issues, Earth is actually pretty resilient. To ability to destroy civilization is pretty much limited to very large nation states.
Not so in a spinning space colony. A small group could easily destroy it. Thus, there will be ubiquitous surveillance and huge social and legal pressure towards "correct" behavior.
That's the plot of "Red Sky-Ceiling", where one person infiltrates a space-habitat with a lethal virus and everybody needs to go into self-isolation. Cool thing though, they could tint red their sky to signal bio-hazard.
By the way, I've done the math, and a habitat like the one in that book would need to fuse 18 metric tons of Deuterium per day to produce "solar light" for an area equals to Virginia state's. Pumping heat out of that thing must be a similarly hairy challenge.
Iconic and beautiful but there's no way there'd be that much green space. We can barely agree to prioritize green space on earth and it's outrageously easier here.
I would think a space colony would have to be far more authoritarian than the earth. In space much more can go wrong without a central authority with almost absolute power which makes it easier to dictate green space.
Oceanic photosynthesis is what you want to also look at to protect, more than half (est. 50-80%) of our oxygen comes from oceanic life like plankton, algae, bacteria. If the oceans go, we're screwed.
Yeah I'm shilling for getting our heads out of our asses and taking care of forests on earth before we go fantasizing about forests in space that no one will ever build.
It boils down to energy (there may be no free safe/good-enough sun in space). When you have to power a forest yourself, it is probably much easier to power a direct co2->co+o2 reactor.
Maybe- theres certainly a lot of frozen CO2 in comets available for harvesting. Where would the CO go, however? It's not the sort of thing you just want piling up next to your habitation zones.
Modern (experimental) reactors cannot do that, afaiu.
Btw, photosynthesis doesn’t produce CO not because it’s more efficient. It doesn’t split CO2 at all, it does CO2+water+light+catalyzers -> carbonhydrates+O2, and this O2 comes from water, CO2 goes to carbs as is.
I'd say it'd still be entertaining though some of it is definitely set in the past as it were. The discussions on how to do rocket boosters have been made a bit redundant by Musk doing it for real for example.
"Rick Guidice" seems to be a familiar name behind the artwork. I too read books with this kind of illustration as a kid growing up and it makes me very nostalgic.
The High Frontier: The Untold Story of Gerard K. O’Neill uncovers the legacy of Princeton physicist and space visionary, Dr. Gerard K. O’Neill, who wrote the 1977 book, The High Frontier: Human Colonies in Space. The book and O’Neill’s subsequent activism sparked a grassroots movement to build Earth-like habitats in space in order to solve Earth’s greatest crises; a vision that is still alive today. Through old stories of “Gerry” as many called him, and the social impact he made on the world, this documentary pays tribute to the unsung hero of today’s space race, while hoping to inspire all ages and walks of life to reignite our planet’s space venturing spirit.
I'm pretty sure I also originally saw these images in another 1977 book I checked out from the library as a kid, Colonies in Space: A Comprehensive and Factual Account of the Prospects for Human Colonization of Space, by T. A. Heppenheimer. Here's a link to a 2017 reprint edition: https://www.amazon.com/Colonies-Space-Comprehensive-Prospect...
Pricing on Amazon for new copies seems to be a little fucked, but there are several used copies available for reasonable prices.
In one of the pictures I believe I see a hang glider. I am breaking my brain trying to figure out the dynamics there. Maybe it's simpler than I'm imagining, but what happens as you fly "up-rotation" at speed?
I've got the same question. My guess is that, unless there's something to keep the air stationary relative to the station, you're going to get what looks like a tailwind which gives you plenty of extra lift, but an outside observer will see a headwind pushing you with the station's rotation keeping you from going into a true free fall.
I really want to hear from anyone that disagrees because there's got to be something I'm missing. Ultimately we probably just need to do some testing.
Yeah, I felt pretty ripped off by NASA :-) As a kid I fully expected to be spending vacations on the Moon by 2010. If Starship meets about 65% of the vision SpaceX has for it I have some hope that I might be able to go into orbit before I die.
All in all though, what NASA really needed to make this stuff real was what SpaceX is working to provide, sending tonnage into orbit at an economic price.
Images of O'Neil cylinders captivated me as a child, and they still do now. So familiar and yet so weird.
Something similar is depicted in the film 'Elysium'. But it is a open torus, rather than a closed cylinder and they never explain how they keep the atmosphere in.
There's no gravity on Elysium's habitats, but there's a centrifugal force caused by the rotation of the torus. However, that wouldn't be nearly enough to keep the atmosphere in, because the walls are only a couple 10s of meters high. For comparison, Earth's atmosphere stretches out for several 10s of kilometers.
And even if their atmosphere wasn't lost, the inhabitants would quickly suffocate and die due to low air pressure. On Earth, there's 10 tonnes of atmosphere pushing down on every square meter at sea level, compressing the air to 1 bar. Reduce that ~100 km column of air to ~100 m, and the pressure would be very much lower.
I haven’t done the math, but I suspect that for habitats where gravity comes from rotation, having a wall without a top to hold in the atmosphere wouldn’t work no matter how high the wall is. That’s because when you move in an antispinward direction your apparent gravity decreases and if you go antispinward at the speed of rotation your apparent gravity is zero. Fast moving particles that are bouncing every which way are going to randomly have zero gravity a significant fraction of the time and just drift away. Liquids don’t do this because they are bound together through surface tension and other mutual dipole attraction forces and solid objects of course have all the atoms bound together, but gasses I’m pretty sure would just float away.
This doesn't seem right to me, why don't astronauts suffocate on the International Space Station? You can pressurize air in a spacecraft, I believe the ISS is kept at ~1 atm.
The habitat in Elysium is quite bizarre. The entire donut is built Cabriolet style flying LEO and protagonists just lowers commandeered space helicopters through inner perimeter. It could be said the Chekhov's gun principle applied beautifully but quite bizarre.
Also there's a scene at the beginning where the main character looks up and it's just hanging up there, seemingly stationary. At LEO it should be zapping across the sky (the ISS orbits the Earth every 90 minutes).
OP is referencing an open air habitat so a comparison with the ISS doesn't make sense. Open air designs do actually work once you scale up the size of the habitat enough. This is where we get the idea of Bishop rings which use a wall a hundred or so km in height to keep the air in. Mckendree cylinders (which are a supersized version of O'Neil cylinders) can also have end caps that are open provided you have a high enough wall.
The main advantage of open air designs is it allows you to use aerobreaking when approaching the habitat which could be a significant save in fuel.
The Elysium habitat in the film has (from memory) walls only hundreds of metres high. So there is no way that would contain an atmosphere for any length of time. I guess their could be some sort of high tech field that kept it in, but it would have to be something that doesn't stop a shuttle entering (as they do in the film).
Yeah, that wouldn't work at all but then again, inaccurate science was far from the only problem that movie had imo.
One possible solution is to ionise the air near the walls and then use a magnetic field to contain it. This would not really prevent all air leakage but you don't really have to as long as it's substantially reduced since even the relatively diminutive size of the Elysium habitat would contain a fairly formidable volume of air. There can also be outside magnets that can arrest the momentum of the escaped ionised air enough so it falls back down to Earth. Then all you need is a tether extending down to the atmosphere with an internal air pump and you have a self contained cycle.
The Elysium habitat in the movie is open topped with walls on a spinning torus not a sealed container like the ISS. On Earth this works because of the combination of gravity and the size of the atmosphere pressing on itself.
The atmosphere falls off exponentially (IIRC). No matter how high the wall is there will be some loss as energetic molecules reach the top of the wall and fall out of the side. But the loss would be very small for a wall that is 100km+ high as very few air molecules will be energetic enough to get that high.
According to the stackoverflow entry above, a 10km high wall on a ringworld would leak about half the atmosphere every century.
>Half of the atmosphere from a Ringworld is a stupendous amount of gas
Yes. So you would need to build it multiple of 10km. Assuming the pressure falls of 75% for each 10km (which seems about right from a quick glance at some tables), if it was 100km high the loss would be 0.25^10 of what it would be at 10km. So 100km wall would be ~million times less loss than a 10km wall.
Half of the atmosphere from a Ringworld is a stupendous amount of gas. 100 years is basically nothing on the timescales you need to think about when building a Ringworld.
You might be able to slow down the loss of gas by putting lips on the tops of the walls and maybe even air jets blowing downward though. Or leave it mostly closed except for a few openings for spacecraft to enter or leave. Also, working out the practical considerations for a Ringworld is an exercise in futility anyway. You are already well beyond practical when you start building one.
I was referring to gravity being constant at the surface over time.
I'm not convinced friction with the wall is going to result in any additional air loss. There is no 'upward' (towards the top of the wall) force component.
> There is no 'upward' (towards the top of the wall) force component.
Friction ensures that whatever air reaches a high altitude near a wall tends to stay at that altitude and spread again on the lower gravity. The difference in pressure between this higher place and a lower one bias the movement up, there is no upward force component on the dynamics of any few components you can choose, it's emergent.
100km isn't enough because no height is ever enough, because friction exists. Any wall will have a flow of air near it going away into space, as a result, the pressure will fall much slower than exponentially.
Off Topic but I finished my last exam today and I wanted to start watching Gundam. I wanted to know if you have any recommendations for which Gundam series I should start with first as someones who likes anime but has never watched Gundam.
I recommend the universal century, one year war movies to get you started: The mobile suit gundam movie trilogy followed by 0080: war in the pocket (a masterpiece of both storytelling and animation).
In fact, starting with 0080 war in the pocket isn't a bad idea given the self contained story.
From there, I'd check out 0083: Stardust memory and move on to the Zeta Gundam tv show.
Then, for a completely different experience, you can check out the alternate universe shows like Mobile Fighter G Gundam or After War Report Gundam X
If you want a super short intro to the series, _Gundam Thunderbolt_ is very good and self-contained. There's currently two hour-long OVAs that compile the first and second season. A third season and movie is planned, but it'll be a while before it's released.
It's definitely one of the more kiddie Gundam series, but it touches upon the themes of the original 1979 show, and is one of the few to depict the Stanford torus rather than O'Neill cylinders.
Once I read the headline I thought of the fantastic books by Usborne (or Plesa in the Spanish speaking world), Future Cities[^1] and the Book of the Future [^2]. These illustrations are super inspirational.
dude thank you so much for posting this -- this video is so incredible and done in such good taste and i am so excited to have discovered the song it uses as well...
You are welcome, I am glad you like it. I find everything great too: the video, the cylinder idea, the music... It helps keeping big dreams for humankind in difficult times.
Miserere, the music, is typical of the cathedral songs and is pretty old (centuries). Here is a good live version: https://www.youtube.com/watch?v=H3v9unphfi0
I have been doing a lot of flying over the deserts using flight simulators. There is so much space still on the planet! At the same time, we can't afford to use any more of it. Let's face it, we never were a benign species for the other ones[^1], not even when we were naked and mostly ate roots.
But without space to live, grow, and try new things, our humanity is maimed. The path of least losing is leaving the planet alone, and making our own habitats.
Plus if we figure out rotating habitats and how to grow nature within them it’ll be a lot more comfortable to live in one of those than to live in the desert
Disclaimer: I am a self taught programmer, not a structural engineer or physicists.
What you say is true but with a couple of caveats.
1. Yes it would likely be cheaper to build domed habitats in the desert. But how long will that be the case? In the desert you have to build on top of sand (or dig way down and build a crazy foundation that would likely cost close to a space habitat) and there may be local governments who aren’t keen on random immigrants coming and building giant domes in their territory.
2. Humans have lived on Earth for a hundred thousand years and have barely colonized the most extreme deserts (both frozen and unfrozen.) The reason thus far is because there isn’t a good economic reason to do so. We’re talking about colonizing the solar system, for resources or whatever, so the idea is that colonizing the desert isn’t sufficient.
3. Space is empty right now so we have to bring everything up from the surface. In a future where people have an economic need to colonize Mars it would make sense to have infrastructure in space that allows for mining/etc so that you don’t need to lift 100% of the resources off the planet. In which case, and with decent automation, it may become cheaper to build habitats in space than it is to build buildings on Earth. If it’s early and there is no infrastructure in space there likely isn’t an economic need and thus those who lived there would be doing so for their own pleasure and would pay a premium.
To clarify: My argument isn’t that we should build these habitats or we should colonize anywhere at all. But if people are wanting to colonize Mars it would be cheaper and nicer just to build rotating habitats with Earth like gravity and whatever weather you choose. I know if worked on Mars I’d prefer to live in a sunny paradise orbiting it than live below the surface while only having 1/3 gravity.
This sort of talk always kills the dreams of orbital living. There's no point building a colony on mars if we can't even build a self-sufficient lunar habitat. But there is no point in a lunar habitat if we can't build an orbital habitat. But there is not point building an orbital habitat if we can't even build a self sufficient desert or ocean or underground habitat.
If we were really serious about this we would have a followup to the Biosphere projects that finally solved the issues they identified. We should have several fully self contained habitats on Earth before we consider building them in orbit or on another planet. People are trying to skip all the way to the end without doing all of the hard work in the middle. It's doomed to failure.
Exactly the point. Every detail of the most hostile spot on Earth is overwhelmingly more viable as a place to homestead than the best imaginable site on Mars. The middle of the Sahara Desert, bang at the South Pole, under the ice at the northernmost bit of Greenland, on a tepui in Venezuela without permission, on a desert island where typhoon waves wash all the way across, all are more pleasant and less likely to kill everyone who goes there in the first year.
So, pick such a place, and try it there first. If you aren't even talking about that, you are far from ready to make a go at someplace massively more hostile to your very existence.
you might be a fan of paulo soleri’s architecture, as illustrated in the book “city in the image of man” - he designs utopian megastructures (arcologies) that exist in spite of desolate conditions while still respecting our connection to nature: residences are at the edge of the city, so that the wilderness is always in view.
You can stay in the guest rooms at Arcosanti, the city he started building in the 70s, it’s wonderful having a glass wall looking out to the barren desert, knowing i can walk 5 minutes up the path to a whole “city” of a cafe, theater, and workshops.
One of my favourite books as a kid wa ‘The Usbourne Book of the Future’, which outlined the next 5000 years of human development and featured a lot of these illustrations.
I’m still bitterly disappointed that the timeline it proposed was not accurate.
Check out the amazing cassette futurism illustrations:
Usbourne really did make some terrific books. Some of them really defined my childhood, from their book about Ghosts that was in our primary school library and gave me nightmares, to the BASIC programming book that was foundational in me becoming a programmer.
They still seem to be making some of the best non-fiction kids books, my kids have some great ones.
Giant ball of water / human aquarium. It will be ice on the outside like Europa, and a nuclear core heating the whole thing (also possibly like Europa). There’s no other practical way. This will be obvious once the majority of humans are permanently living beneath the surface of the ocean.
Signed, former NASA guy, unpopular with the spacecraft engineering crowd
Just looking at the designs - almost all have a rounded base - pretty sure that would cause a weird 'gravity' direction anywhere except the centre-line of the ring.
(Sorry I've been readying The Expanse series too much and it's making me very pedantic about spin gravity)
The edges of the habitable area should be treated as if they were hills getting gradually steeper.
The direction of gravity won't be perpendicular to the curvature of the hull, but who says you need to stick to the hull? Even on Earth, people don't stand diagonally on hillsides. We build stairs, towers, and terraced gardens, with man-made floors perpendicular to the direction of gravity.
Some of the illustrations are more realistic than others in this respect.
If the floor is curved, then the direction of gravity would not be perpendicular to the floor (except at the exact apex of the curve), so you'd have a weird sensation of standing on a slope all the time.
Instead, you'd probably want either a non-curved structure, or a flat false floor inside of it that is perpendicular to the direction of gravity. That would probably work ok though, since it would give you an easy place to run e.g. cabling, air handling, fluids, etc.
>so you'd have a weird sensation of standing on a slope all the time.
I mean, lots of people live on slopes here on Earth. It's actually a pretty desirable terrain, as long as you're not farming it. You can see in many of the toroidal stations that the hillsides are terraced and treated like slopes.
Sure, but as you mentioned, they're usually terraced, and you wouldn't e.g. build a house on a slope without leveling the site first, so your floors are perpendicular to gravity.
You need the edges to be curved for structural reasons. It’s also a giant pressure vessel and pressure vessels don’t take right angles very efficiently. Also, gentle hills are fine.
I recognise these illustrations, they were used for cover for an edition of a Swedish translation of Rendezvous with Rama by Arthur C Clarke. Probably borrowed by the publisher but I assumed they were made for the book.
To me the definitive SF treatment of these things is Alexis Gilliland's Rosinante series.
The idea of mirror flaps swinging around as the cylinder rotated was ridiculed, and brilliantly replaced with the Mitsubishi Dragonscale Mirror Array, a cone of millions of individually-steered mirrors. Clever re-uses of that drove major plot points both as a weapon, a la Archimedean defense against ships, then as the light pump for a beam weapon, which then became remote power for vapor-phase asteroid ore refinement, and then for a capital ship, all background for solar-system-scale political intrigue.
Big nostalgia. I was born in the mid 70ies, and remember having books my parents got me with these sorts of techno-utopian illustrations. It all seemed so cool, and maybe we were headed that way.
Instead of perpetual manned space missions I’d like to see an experimental off world self sustaining biosphere. Put it in orbit, on the moon, or Mars and try to keep it alive while maintaining or increasing biodiversity. Make it modular so that it can be expanded and over time gradually introduce more complex forms of life.
There are many experiments of various types of organisms in space but I’m not aware of any that test and try to sustain entire ecosystems, something that’s essential for prolonged human life off of this planet.
Biosphere 2 was too ambitious and they had humans so they needed to cheat. Also the gravity and background radiation levels are no different. We really need to do it outside of earth.
That's not true. You can easily make aself-contained biosphere yourself using just a glass bottle, some water, dirt, and a few select species of plants, algae, or insects/orthopods [0]
This actually feels more plausible to me than colonies on Mars, to be honest. The delta v to get materials from one place to another in zero g is much smaller, so travel between cylinders would be pretty cheap, and solar panels would be easy to make thin and cheap too. Mars on the other hand has all the disadvantages of being in a gravity well but without the breathable atmosphere of earth or mineral wealth of the asteroid belt. Worst of both worlds.
I get the sinking feeling that large earth orbit space stations will never happen because they are too fragile to space debris. It's like imagine any single person could destroy the entire freeway system of a 10 million person metropolis in a way that would take decades to recover from anytime they wanted. Maybe that's not how fragile it is but it's how it seems. I suppose if we ever perfect force fields we can "raise the shields"?
I recently listened to the audiobook of Arthur C Clarke's Rendezvous with Rama. It's full of great descriptions of a habitat akin to one of these, especially with the experience of getting from the entry-point at the axis to the outer wall.
It might be the only book that's ever given me the feeling of agoraphobia with some of the descriptions. I'd love to see some kind of adaptation, but it's not sure if a TV screen could ever do justice to the scale.
I was OBSESSED with the first image of the toroidal station as a kid. Haven’t seen it in so long and this instantly made me feel like I was 8 years old again.
Looking at what the past thought space exploration would become is really fun. Disney and Wernher Von Braun collaborated to make a happily imaginative view into space exploration back in 1955.
So boring. So, like the earth except a lot more expensive and trapped in a tube. Meanwhile, with a little bit of genetic engineering we could turn ourselves to self-propelled, solar-powered, AI-augmented interstellar rockets.
If you enjoy fantasizing about these feats of engineering, mega-structures and space travel, I'd recommend checking out the Bobiverse Series by Dennis Taylor!
Super funny, and very relatable, if you're a creator or engineer.
I really loved these when I was a kid and it was a major reason I was so enamoured with human space travel. Nowadays I look at this and think "who'd have the cash to build and operate that?"
And the idea is to lower the cost of all the various technologies required and then operate and build them cheaply using extraterrestrial materials without any more continued reliance on Earth’s resources. NASA was supporting this idea of asteroid mining (for in-space use) at one point with the Asteroid Redirect Mission (ARRM) which was canceled and replaced with Artemis.
I've done various estimates on what it would take to generate a truly self-sustaining (no earth dependence) non-terrestrial (space-based or planet based) society and I don't think it's practical unless you're willing to spend the equivalent of $10 trillion dollars or more over 100+ years.
What a lot of concepts ignore is material requirements, which is super-important.
A good example is Larry Niven's Ringworld. It's a cool idea in the early days when people were thinking about mass-to-living-area ratio but to produce Earth-like gravity at an Earth-like distance would require the thing to spin at (IIRC) ~1.5m km/h. The centrifugal force would tear that apart.
Likewise, people mistakenly view a Dyson Sphere as a rigid shell around a star. That was never the concept. This misconception is so common it's led to the term Dyson Swarm, which was always the original intent: a "cloud" of orbitals around a star all moving independently.
The likely future of space habitation is (IMHO) going to use the humble O'Neil Cylinder [1]. This is nothing more than a cylinder a few miles wide and maybe a couple of dozen long. Such a cylinder could potentially house millions. They're large enough such that spin gravity wouldn't be disorienting and small enough such that they don't require exotic materials (eg space elevators for Earth require exotic materials we haven't even theorized yet other than possibly graphene).
So an O'Neil cylinder can be built of nothing more sophisticated than stainless steel.
You have options of joining them to other cylinders. You can build a "ladder", which is a series of orbitals all in the same orbit but slightly displaced. You could even run cables for transportation between them. You could construct networks of these things.
You put solar cells on the outside and a window at one end, possibly using refractive materials down the center to create more pleasing diffuse light and the whole thing is reasonably low tech and low maintenance.
You could even build them by hollowing out asteroids and other space bodies.
The mac daddy to the O'Neil Cylinder is the McKendree Cylinder [2]. Instead of being a few miles wide, it might be hundreds of miles wide and much longer. This is beyond the tensile strength of stainless steel but within the theorized limits of graphene.
Such a cylinder could comfortably house billions of people.
As much as it's cool to have things like the micro-gee environment of the ISS, I honestly wish we'd start building prototypes for spin gravity. This would greatly simplify living in such an environment for extended period of time.
To give you an idea of how efficient thing is for living area, IIRC the estimate is about 1% of the mass of Mercury could consume essentially be a complete Dyson Swarm around the Sun and comfortably house a quintillion (10^15) people.
Planets are nice and all but are horribly inefficient uses of mass to create living area and come with some serious negatives, not the least of which is the energy cost of entering and leaving such a gravity well.
This is also why looking for the signature of such a Dyson Swarm as evidence of extraterrestrial spacefaring life makes way more sense than pretty much any other approach. Saying that we're less than 1000 years away from having this kind of space-industry is beyond conservative. 1000 years ago we were throwing spears at each other.
What I'd prefer to see is a space construction that is continuous. Imagine a ring station, but one that is cellular in nature- lots of smaller modules that together form the huge station. This allows one to construct and add further modules over time, growing as needed.
The beauty of this design principle is that we could start today. Design the first iteration of these modules, with the intent to fit them into SpaceX's Starship (or whatever heavy rockets come next). Launch 10 or 20 of them, connect them, and spin them up to 1/5th gravity, something not too hard to do. Add modules in the centre of the ring that are zero-G, where zero-G things can be done- but allowing those who live on station to live in mild gravity at least.
All the while, you can dream big. You can plan for how this station goes from 10 or 20 small modules to thousands.