True, but the ISS also does a LOT of recycling of things like water. It’s not a perfect closed system, nor intended to be one at this point, but due to the costs of getting there there is ample incentive to come up with ways of making it more like a closed, self-sufficient environment. It’s a test-base for such things, while being near enough that if something goes wrong we don’t kill everyone aboard.
There are been considerable progress in the aforementioned water recycling systems, and growing plants (including edible ones) in space on the ISS. It’s not terribly sexy or well-publicized but it’s a necessary step to getting, say, a Moon colony. If we can’t get a viable Moon colony (or equivalent) we certainly can’t build a generation ship.
Real talk though… forget near-earth orbit. Projects like these first need to be tested on the ground where it’s cheaper. So far we couldn’t even get Biosphere 2 to last for 2 years. Until anyone’s able to start a project where people agree to live for (say) 20 years in a completely sealed habitat in Antarctica, that means nobody’s serious enough to consider building a 100 year generation ship, let alone living in it.
This is how we know Elon Musk isn’t really serious about going to Mars. AFAIK he’s investing nothing whatsoever in figuring out how to support human life in a 2-year space trip. This part needs to be ready when the transportation is ready, and it’s not happening.
Yeah, Earth-based sealed habitats aren’t ready yet, and that’s where the R&D needs to be done, because when an Earth-based sealed habitat fails, you can easily unseal it to rescue the inhabitants (either re-supplying them with something that it turns out they didn’t have enough of, or worst-case, just getting them out). Biosphere 2 failed, but that’s hardly surprising, since it was our first attempt. We need to keep on trying, and fixing the problems as they come up, until we eventually run out of problems. Which, yes, will take a while.
And we’ll also have cheap, easy, and routine travel and trade within the Solar System for a long time before we leave it. Any starship will be built from raw materials mined from asteroids or (at worst) the Moon, not lifted from Earth.
I’m assuming that if we’re at the point of contemplating sealing up a near-Earth space station for a decade or a century, we’re already at the point of having multiple large near-Earth space stations, perhaps ones containing hundreds or thousands of residents, just not ones that are completely isolated.
Another thing I thought of - who says we have to launch the generation ship during the very first generation?
Build it, crew it, seal it up, then leave it in orbit somewhere for a couple of decades, or longer. If something unexpected goes wrong, they’re still right there to be rescued. Once they’ve established that both the ship and their culture can survive long-ish term, then send them on their way.
I mean, the trip is likely to take hundreds to thousands of years. By the end of it, will they even care about the first 50 years of going nowhere?
I don’t think generation ships will be a thing, unless they are an end unto themselves (i.e people plan on living in them as home, forever). The problem of keping a large number of people alive in an artificial environment for centuries is far, far more difficult than the problem of keeping a bunch of frozen embryos alive, then developing them with the help of AI once a suitable planet has been found and a base established robotically.
How about a system of robotic probes, each of which carries frozen embryos. If a planet is not found suitable for humans the robots just develop it for resources and discard the embryos. If one of the probes lands on a planet that humans could survive on, the robots create habitats, birthing and raising facilities, etc. Once all are complete, hatch the embryos.
Send these out to a hundred star systems, and hope that at least one of them can support a thriving colony. As you develop better and faster ships, just send them to new targets, letting the old lumbering ones continue on their way. There will be no shortage of target systems.
A more interesting way to travel between the stars would be to hitch a ride on a rogue planet. There are probably trillions of them in the spaces between the stars in our galaxy. An advanced civilization may have all of the closet ones mapped out, and know where they are going. Some of them may even be habitable underground, with large reserves of heat energy and materials.
Find a rogue planet coming your way that’s heading near a star you want to go to. Land on the planet, build out a base, and settle in. In 100,000 years or a million years, you wind up at a new destination. Or by then you like your new Rogue home so much that you can’t conceive of leaving it. This would work well with robotic probes. Just seed every rogue planet that coms near. The ones you can make habitable get their embryos unfrozen.
I’m not sure this is much easier than just taking your own ship there… Rogue planets are generally still a significant distance from stars, even at their closest approach, so you’ll need to go out to them, and then come back in from them at your destination star. And you’ll also need to match velocity with the planet, and if you can do that, you can put your ship on a trajectory for the same destination in the same amount of time. The only advantage I can see is that you’d have a lot of raw materials at hand for the whole process.
But that’s the point. You’re taking a whole planet on your journey - one that’s already on a vector close to where you want to go.
Travelling a third of a light year to a rogue planet, then traveling maybe a light year or two at your destination is a whole different proposition than travelling hundreds of light years in a generation ship.
Or, perhaps you can alter the direction of the planet given enough time. It’s not gravitationally bound to a star, so if you can nudge it early enough you might be able to make it transfer much closer to your destination.
A replicating probe might find a rogue planet ideal. Just land one on the rogue, then have it build out the manufacturing base needed to fire off more probes, and continue making/releasing them until you’ve used up the plasnet. That way you don’t have to ship all the resources with the probe, and each probe doesn’t have to start from scratch. Perhaps when we have the capability to image rogue planets we’ll find out that they are prime real estate for aliens.
That actually makes some sense. Presuming that we actually figure out how to design closed habitats that will work for a minimum of hundreds of years: then instead of giving them the primary intention of starting settlements, fill them with volunteers who want to set up societies in those closed habitats, whether because they think it’s a great way to do research, or because they want to try out a different sort of society than they can find at home, or because they’re afraid something will happen to this planet and they want to be elsewhere.
It then does also make sense to supply the ships with some means of guidance and with planetary exploration tools, including some small ships capable of planetary landings; if only because humans are curious and, just as lifetime planetary residents are curious about the rest of the universe, ship residents presumably will be also. Supply them also with whatever information and tools are available at the time they leave for terraforming, just in case.
When they come across a planet fit to send a landing ship down to, they can stop and hang around for a while – if they haven’t lost too much information about the universe, they’ll probably be curious enough to do so; and they can pick up some fresh raw materials while at it, if they want more of something. If they also think they can make the place habitable by humans, whether in one generation or in twenty, then do that; once it’s done, drop off some volunteers (or, possibly, some unwillingly evicted convicts and/or malcontents), note the location in case anybody ever wants to come back and see what happens – and the generation ship goes on its way, most of its crew settled in as permanent inhabitants. They all just think this is a normal way to live by now, after all; and most at least of those who couldn’t stand it probably got weeded out in the first few generations. (Whether this process will also have weeded out those best suited to colonize a new planet is another question; but one that’s probably only answerable by trying it.)
That avoids the whole problem of figuring out how to raise human children with no human adults present, which is a complication brought up by sending AI’s out with embryos. Getting our medical and AI abilities up to a point at which AI’s could grow the embryos to birth, far as we are from either of those, would I suspect be a cinch compared to figuring out how to get those AI’s to raise the embryos to any reasonably sane and recognizably human adulthood.
One of the main impetuses, that I hear about in books, podcasts and videos is, “We might be alone in the universe and if so, we have a duty to protect life”, or something there abouts.
As Gray asks in the SETI thread:
I think part of the bias for saving life is it just seems like we should. But any future people haven’t come into being and once all the people alive today are dead, we can’t remember or morn for the end of life in the universe.
We try, with thought experiments, to figure out how to get around losing our precious spark. How? Populate the universe of course! It’s easy, haven’t you seen Star Trek? But it’s not of course. A far easier, and smarter, plan is to not fuck this planet (and life) up. Ultimately, any and all life has an expiration date, anyway, if the Heat Death theory of the universe is to be believed so ultimately what’s the point? We have another 5 billion years here (yes I know, meteors, solar flares, Yellowstone volcanoes, etc. But any of those things should be easy to stop as opposed to sending a generation ship to Proxima Centauri b.).
I realize I’m kind of fighting my own hypothetical here but it seems so hand-wavy to say ‘on generation ships we will have to regulate the population by regulating births’. So why not just do that on Earth? Because people. Why fly to Proxima Centauri b to terraform it, when Mars is right next door? Because even with Earth as a supply base, it’s too damn hard. If we can terraform Mars (or Proxima Centauri b) why not just fix the climate change issues here?
The answer: people. The same basic people we propose sending out.
If we have the ability to have…
We should have the ability to save this planet. Not, Sam Stone, that I don’t think that’s a fantastic idea. It is! I’m just spit-balling here.
An interesting variation on this is to just build habitats farther and farther out from Sol. Colonize the Oort Cloud, then the Kuiper Belt, and at some point, the habitats are far enough out that we can legitimately debate if it’s in orbit of Sol, or Alpha Centauri. At some point, it becomes obvious, and we’ve bridged the gap between systems.
This is a constant problem for humanity. Sure, our descendants are allowed to disagree with us. If they decide that populating the universe is a bad idea, they’re welcome to decide to do something different.
I’m not going to spend too much time worrying about that, though, since we have no way of knowing what they’ll think. If they all want to just throw themselves into the nearest star, well, they’re welcome to it.
I’m vehemently opposed to any attempt to populate other places in the universe, including by manufactured habitats, instead of taking care of this one.
I am, however, in favor of taking care of this planet; and, in addition, if we’re able to without screwing up this place, trying out going someplace else; out of sheer curiosity, if nothing else. I wonder what kind of societies we’d get, in selfsustaining habitats, if we ever figure out how to build one. And it’s possible that, in trying to build one, we might learn useful things about how to keep this one going.
I am highly dubious that anything remotely resembling humans is going to be around when the state of the sun becomes an issue (meteors are another matter; but learning about space travel might also lead to learning about meteor detection and diversion.) And you know what? I don’t think it matters. We’re not eternal; not as individuals, not as a species. Life itself may not be eternal. But we’re here now. Let’s do the best we can with it. If there’s nobody at all in existence in five billion years, or no humans in five million – so what? That doesn’t make our being here now, or a thousand years from now, or a hundred thousand, not real.
So you propose a system of robotic probes, each containing frozen embryos. I think you’re assuming the development of artificial wombs, and then who is going to raise the children to adulthood?
I think what you’re describing is a bit like what’s described in the HBO Max series Raised by Wolves.
Have the AI built a habitat and start raising humans. When it fails, clean up and try again. Learn from the experience. After several hundred attempts, chances are it’ll probably be able to create a viable human colony
Kind of hard on the kids of those several hundred attempts, isn’t it?
That is, I suppose some of the failures will be early enough in development that the embryos/fetuses won’t know anything about it. But some of them are going to be very nasty failures involving children at various ages all the way up into adulthood.