Life on a generation ship.

[Drunkrobot]

In this thread (http://forum.kerbalspaceprogram.com/threads/65341-Evacuate-Earth) there is a discussion on the plausibility of constructing an interstellar spaceship housing 250,000 people for about 1 human lifetime with a 70 year deadline, starting today.

This scenario raises an intriguing question: How would a society forced to live onboard a massive spacecraft for decades, even centuries, with no contact with Earth (the scenario discussed in the thread had the Earth destroyed just as the ship launched, leaving the passengers the only humans still alive.), be affected?

Here is the scenario for discussion: A significant number of humans, but only a tiny fraction of the current population (Let's stick with the 250,000 number, since it's large enough for full scale government to still make sense, and small enough to hammer it in that we are very much an endangered species.) are onboard an O'Neil cylinder-type spacecraft heading towards a "nearby" star system, to colonize a planet that is predicted to be Earth-like. The ETA is 300 years (the actual travel-time to the nearest potential "Earth Mk. II" is a discussion for another thread, I choose 300 simply because it means the last several generations onboard would've been born on the ship, and have accepted existence on it as a fact of life.) We can't put people in cryosleep for 3 centuries and bring them back out, so we have to go with a "generation ship", the people who depart from Earth have children, age, die and pass control of the mission to their children, who repeat the process, until they get to the destination. Contact with the rest of humanity is impossible (whether the world has ended, or someone forgot to install the receiving dish is up to your imagination), so the "spacers" are completely cut off from their home, only having a repository of all knowledge and culture the human race has collected up to the day the ship leaves.

The goal is to reach Earth Mk. II without everyone killing each other during the transit.

How would humans have to adapt from a social point of view in order to succeed? Ignoring any sort of physical alteration, how would we have to change the way we interact with each other, how we organize ourselves, our very behaivour?

[Skyler4856]

I see three possible scenarios, The first... everyone holds hands and sings kumbaiya, given what I know of human interaction this seems highly unlikely. The second involves a militaristic fascist 1984 type government. The third and most probable is that the population of the ship tears itself apart in a mutiny.

[Klingon Admiral]

The main question is probably if the generation ship can sustain it's crew with food, water and air. If these conditions are given, the crew wouldn't probably totally wipe itself out. Minor self-adjustments of the population are still probable. As long as about 5,000 not too closely related people survive the trip, humanity is in rather good shape.

[Themohawkninja]

Social adaption is a given if you ask me. Humans, some way or another will find a way to create a social structure.

That being said, the best way to pull it off, in my opinion, is to have the ship have very few automated procedures, so it forces as much of the crew as possible to work, thereby keeping them out of trouble and in shape. The whole thing would most likely have to be military, as it gives you a basic hierarchical structure to go off of, along with some order, and a basic judicial system.

From there, you need to make sure that each of the 250,000 people on board are people that will benefit society as a whole, and/or help keep the ship in order ("order" being both physical and social). This includes mechanics, doctors, members of the military, lawyers, farmers, and so forth.

Then you need to take into account food. A ship designed to sustain 250,000 people for 300 years can't just haul freeze dried food and/or K-rations. Space farming will need to be done, and this can only be achieved by hydroponics, and a very efficient water filtration system to allow liquid waste to be purified back into water, and the leftover products used as fertilizer for the plants, or possibly burned as fuel.

Since people are going to be born and die on this ship, appropriate actions are going to need to take place. Taking care of the dead allows for two possibilities. You could either burn them, and try and use the materials in the ash, or chuck them out of an airlock to reduce the mass of the ship to make the fuel usage that much less. Births will be a bit more complicated. Due to physical complications with micro-gravity fetal development (at least in rats, but this is probably also true with humans), a large centrifuge will have to be a part of the spacecraft. Such a centrifuge will contain temporary living quarters for pregnant women, maternity wards, and (if need be) where the child will grow up for the first few years of life.

I suppose that about does it as far as I can tell. Power the ship with a nuclear generator or two, make sure to have spare fuel rods stored in highly neutron reflective material, and you shuold be good.

[peadar1987]

Actually, you want the spare fuel rods stored in a material that's NOT neutron reflective, and especially not neutron moderating. I've worked with nuclear fuel, and the only protective gear you have to wear is paper overalls, a dust mask, hairnet, and gloves. This isn't to protect you from the fuel, it's to protect the fuel from you. It's going in a highly precisely-engineered machine for the next six years, and it better not be covered in your sneezes, dandruff and mucky fingerprints!

Spend fuel should either be ejected or preferably reprocessed. The ideal power source would be something along the lines of a molten salt Thorium reactor, which would "breed" its own fuel, and be capable of burning most of the longer-lived fission products of the primary cycle, meaning the only waste would be small volumes of short half-life stuff. Nasty for a few decades, but not much of a problem afterwards

[Scotius]

Spare parts/colonisation equipment/'day-to-day' stuff. Such ship would require either huge cargo bays containing literally everything such a society would need - from furniture to toys. Or make everything out of easily recycleable plastics or something, take couple of Megatons of raw materials and fabricate it when needed.

[Themohawkninja]

Actually, you want the spare fuel rods stored in a material that's NOT neutron reflective, and especially not neutron moderating.

Why not? Wouldn't you want the spares to last as long as possible? One set of fuel rods won't last you 300 years, so you will need spares to replace them, and since you can't turn off radioactivity, shouldn't you make some attempt to keep all the radioactivity contained inside the fuel rod as long as physically possible?

[Pyre]

Why not? Wouldn't you want the spares to last as long as possible? One set of fuel rods won't last you 300 years, so you will need spares to replace them, and since you can't turn off radioactivity, shouldn't you make some attempt to keep all the radioactivity contained inside the fuel rod as long as physically possible?

Doesn't work that way. Radioactivity isn't something you can keep in a box. Making the container out of neutron reflective material means you have more neutrons passing through the fuel, causing it to "burn" faster.

[peadar1987]

Why not? Wouldn't you want the spares to last as long as possible? One set of fuel rods won't last you 300 years, so you will need spares to replace them, and since you can't turn off radioactivity, shouldn't you make some attempt to keep all the radioactivity contained inside the fuel rod as long as physically possible?

It doesn't really work that way, it will naturally decay at the same rate, whether it's in the vacuum of space, or shielded in a massive lead box. There's no real way of "keeping it in", except maybe by containing decay products, in which case, you're not preserving your fuel, you're just keeping the by-products in one place. Some reactor designs can actually burn fission products, but it's not particularly efficient, and the quantities produced by natural decay are tiny.. In fact, if you're reflecting neutrons back at the stored fuel instead of letting them escape, they're probably going to cause a few fissions on the way back, actually making the fuel decay faster.

Most materials used as nuclear fuel are stable over the mission duration anyway. Plutonium-239 has a half life of 24,100 years, Uranium-235 703.8 million yeas, Uranium-238 4.4*10^9 years, and Thorium-232 1.4*10^10 years.

The major problem with nuclear fuel storage is to do with criticality. Basically you don't want a chain reaction occurring in the fuel when it's outside of the reactor. You don't want to store too much fuel together, and you don't want to let it get into contact with a moderator. We had very strict rules where I worked when doing anything near the fuel, Only 4 people were allowed in the room when there was fuel in it, in case the water in our bodies was enough of a moderator to cause criticality, and if you wanted a refreshing drink of water, the closest you were allowed to bring it was about 50 metres down the corridor!

Edit: Ninjad!

[Drunkrobot]

The ship in the scenario has already been designed and built for it's mission. There is enough resources to keep the 250,000 people onboard alive and healthy, with a small surplus capacity for up to 10,000 should one generation get "too busy". We're assuming that the ship either has facilities for recycling waste into more supplies (farms and recycling centres), or raw materials in storage to make up for less than 100% re-usability. Every failing part is broken down into it's constituent materials, reassembled as a working part, and put back into it's machine. Literally the only thing that can go wrong is the cargo: the 250,000-strong society that we're talking about.

[Champ]

The ship in the scenario has already been designed and built for it's mission. There is enough resources to keep the 250,000 people onboard alive and healthy, with a small surplus capacity for up to 10,000 should one generation get "too busy". We're assuming that the ship either has facilities for recycling waste into more supplies (farms and recycling centres), or raw materials in storage to make up for less than 100% re-usability. Every failing part is broken down into it's constituent materials, reassembled as a working part, and put back into it's machine. Literally the only thing that can go wrong is the cargo: the 250,000-strong society that we're talking about.

I understand you are talking about social organisation, nothing technical with the ship.

I think 250000 is small-enough to create a direct democracy, and i have no doubt it would be the only viable solution.

Anyway, this ship is a closed society, and it would allow for interesting social experiments, i think...

[Wahgineer]

Considering their predicament, the people on board would probably just except the fact that they're stuck in a giant spinning oil drum destined for a destination 300 years down the road. Once they except that fact, they'll settle into a day-by-day routine, undergoing the necessary processes to allow for the journeys continuation.

Slightly out of context: This is why we need warp drives. We could build more ships faster, that take less time to get to a nearby star (think 3 weeks instead of 3 centuries).

[Ralathon]

Why not? Wouldn't you want the spares to last as long as possible? One set of fuel rods won't last you 300 years, so you will need spares to replace them, and since you can't turn off radioactivity, shouldn't you make some attempt to keep all the radioactivity contained inside the fuel rod as long as physically possible?

If you encase nuclear fuel with neutron reflective material you just send the neutrons back into the fuel where they can cause new reactions. If it is a moderator as well your fuel can even go into meltdown. So you want the nuclear fuel in an isolated environment that keeps it cooled and preferably out of reach from the public (Don't want those things to get lost, you need that power). So you would probably encase it in thermally conductive plastic (Also helps deflect the cosmic radiation a bit) and bolt it to the outer hull.

Anyway, I suspect a rather interesting society will form. At first I expect major psychological trauma on a wide scale thanks to survivor guilt, not to mention that a spaceship isn't a very pleasant environment: They are built for function, not pleasure. So I think you'll see a lot of suicides and psychological breakdowns in the first few years. Since people with a fragile mental stability in a spaceship is a very deadly combination the government would have to be extremely strict. A real police state that monitors your every move and takes you to forced therapy under 24/7 surveillance at the slightest hint of depression or mental breakdown. It won't necessarily be a bad place to live, that would just work against their own goal of keeping people sane. But if you have a weak mind you're going to have a bad time. The world from the anime Psycho Pass is pretty close to how I would imagine this society (Minus the Sibyl system). Utopian from the outside, but with deep moral flaws to keep the system running.

True capitalism and a free market are out of the question. I doubt the engineers would build in enough overpass on resources so that 1 person can have significantly more living space, energy and food than another and still have both survive. It simply isn't efficient engineering and morally dubious: "Yea, we could totally safe 1000 more people! But we need that overpass to make sure the rich guys can stay rich..." So food, beds and water and other essentials would be freely supplied by the government. If there is a currency system it would focus purely on luxury goods such as leisure time, rooms with windows or access to entertainment systems. And even then it would be heavily regulated to avoid a small minority ending up with most of the goods. The space ship is a closed system, so you can't just import new goods to keep the rest happy. Jobs would likely remain much the same. Even in space you'll still need barbers, nurses and plumbers. Though I think they'll place a lot of focus on engineering and entertainment. Engineering to keep people alive and entertainment to keep them sane.

If humanity manages to stumble their way through the first few years people will likely relax a bit and start to form families. Birthrates would be heavily controlled so the ships recycling system doesn't get overly taxed. The kids themselves would be fine, according to the OP they're in a O'Neil cilinder, so they'll be subjected to a comfortable 1G. This also raises demand for teachers, so that field will likely see a major boom. Their science lessons are going to be awesome, just take the elevator to the central axis and you can float in 0G while your whole world spins around you. A trip of just a few minutes for the best demonstration of Action = Reaction, centripetal force and momentum conservation in the universe.

After about 25 years I think the government will start to cut some slack to humanity. Most of the population is now either born on the ship and thus accustomed to living in space, or has been around long enough to know that they wont crack. I also doubt that humanity would reach a high enough birthrate to keep the population constant. Even in first world countries today the birthrate is below replacement levels and we aren't floating around in a tin can with limited resources. So as the population drops the government can relax its hold on the economy a bit since there is more to go around per person. Since there are more resources available I think some extinct forms of art will resurrect. You aren't going to waste atoms on paint if those could also be used to feed someone, but now that there's a bit more to go around people can afford things like painting, sculpting and generally making the ship feel more like a home than a nuclear submarine.

Science, especially big physics would grind to a crawl. The ship isn't equipped with sensors accurate enough to allow physicists to get the data they need. So we won't see hoverboards powered by Higgs fields by the time we reach the destination. But other fields suffer as well. Biology, for example, has essentially turned into bookkeeping. You can't observe the behavior of chimps if you only carry a few frozen embryos. So most biology would focus on gene sequencing, observing the population of crops and humans to detect problems and study their behavior in a closed system. We would still keep everything we know today around (Data storage is light and cheap), but we won't expand on it much.

[Kinglet]

What if you replace the people with space cores. It would be VERY loud.

[Dispatcher]

Well, we're on a generation ship. We just need to figure out how best to move Kerbal.

[Zaeo]

Looking at this from a different angle...

If say we start with 250,000 people, What would their ages be?

You don't want your entire population to get old all at one time. Thus, you would have to stepladder the population selection's ages.

As hard as it is emotionally to accept, older people would be suited mainly as teachers, to teach the younger generation, and then pass on. any sort of physical labor is not very well suited for them, so things like farming would be very hard to do for them. Certainly, any sort of software programming is also an option, but that's automation, Which you want to avoid. Too much automation breeds on reliance and ignorance, "Why do I have to know how to do this? The Robot does it for us." and when that robot breaks, maybe 10 years after its creation, we could potentially loose knowledge on how to do the task, based on the amount of time passes of reliance. in 10 years time, the blueprints could be lost in the sea of storage drives that will no doubt hold most of the information that the generation ship will have.

Too young and you are a liability, potentially getting into something you aren't supposed to, not being able to adapt as easily. I'm talking about the original young ones, the ones who knew earth. Ones born after never knew earth first hand, and are more likely to be complacent. That raises a question of "How young, and how old of a child can you bring with you?" ages 5-13 will have gained enough of an understanding of themselves to become "selfish", Whereas 14-17 might be ideal, as they are growing into the primary work force. Too young to remember earth is good too, as they will be able to adapt to a life if its all they know.

The next line of considerations: Crime, murder, etc. How will that be handled?

Do we place them in confinement, wasting resources while protecting those who stride to succeed? Do we kill them?

At any rate, anyone who murders another inhabitant of the generation ship should most certainly, When found, be dealt with harshly. That, however, is a double edge sword. If they knew the sentence is death, most people will not commit any crimes. However, those who are mentally unstable might not care. If they know that they will die, and still murder someone. Then if your police force is "lazy" and give up the investigation, and pick someone at random to take the blame, then who is to stop them? This has to do with human flaws, no matter what they are like initially, the psychological strain put on the residents would be greater than ANYTHING anybody has ever felt, knowing they can never return home. Prisoners of war were still on earth, they were still "home" in a sense.

The point here is, no mater how strict your selection process is, you simply cannot predict what humans will do in the future. The stress the first generation will experience is beyond measure. If...IF it makes it past the first generation, It will be somewhat smooth sailing from there.

Next we have the midpoint to consider: 150 years though the trip, interstellar flight.

By 150 years, we are literally in the void of space, far past the solar Heliosphere. What does this mean?

It means we are blind.

We have no relative positioning of what we should be going towards. 150 years is more than enough time for electronics to fail. If we so much as push our course off by .000001 degrees, we could miss our target completely at the distance we are at.

We could also get caught up in a number of nasty issues: Rogue planets, black holes, black dwarfs. just being near one of these objects, could affect our trajectory, if we aren't destroyed in the process, bringing us to my previous point. If the right electronics fail at the wrong time, and we cant correct our coarse at this point, we are doomed to wander the void of space, with only luck to rely on.

Metals that are not corrosion resistant also will degrade quickly in our enviroment. Iron will rust, copper tarnish, they would need to be replaced, or treated and reused. in the vaccum parts, that is less prevalent, as no oxygen means no rust, so the hull will remain largely intact. That leads us to a few material possibilities: Plastic being the most obvious. It doesn't degrade, and can retain its shape for a long time.

Here is what i think is going to be the most dangerous times:

0-50 years, our first generation undergoing extreme psychological stress, far beyond what any human to date has experienced

75-170 Any sort of hardware failure that isn't detected that can result in the trajectory being altered could prove to be fatal.

250-300 Upon final approach, the final generation has to experience a similar psychological stress experienced by the first generation. Leaving behind life as they knew it to create a new one on Earth-2. it wouldn't be right to call them Humans any longer. We would be adapted for space, and re-entering a gravity based enviroment could prove to be fatal. Not including any foreign bacteria that the new planet might have already. Sickness and disease is literally the most dangerous aspect of a generation ship.

0-300 Bacteria, sickness, and infections in general are an issue throughout the ENTIRE trip. out of control fires*uses up precious oxygen* and micro meteorites*perforating the shop hull in weak areas*

No matter which way you go about it, it certainly isn't going to be an easy, safe trip.

[Scotius]

Entertainment? You know what will be built by crew first? Stills Moonshine will provide both entertainment, and alternative currency. I wouldn't be too worried, though - globalisation and worldwide communication is still a fresh development for humanity. Up until XIX century people living even in civilised countries could spend their entire lives without leaving their town or village. We are social animals after all, we need some sort of community to survive. If there is no such thing, we will create it.

[theend3r]

If you encase nuclear fuel with neutron reflective material you just send the neutrons back into the fuel where they can cause new reactions. If it is a moderator... blah blah blah

Use 232Th, problem solved.

[Themohawkninja]

Use 232Th, problem solved.

I'm no nuclear scientist, but I fail to see how a different nuclear material will change anything if both substances work off of the decay of their radioactive isotopes.

[SuperBigD60]

The ship in the scenario has already been designed and built for it's mission. There is enough resources to keep the 250,000 people onboard alive and healthy, with a small surplus capacity for up to 10,000 should one generation get "too busy". We're assuming that the ship either has facilities for recycling waste into more supplies (farms and recycling centres), or raw materials in storage to make up for less than 100% re-usability. Every failing part is broken down into it's constituent materials, reassembled as a working part, and put back into it's machine. Literally the only thing that can go wrong is the cargo: the 250,000-strong society that we're talking about.

I bet the first generation or so (depending on how diverse the ages are, but in any case, I mean the first adults) would likely be very shell-shocked from whatever catastrophe destroyed the earth, be it a supervolcano (less likely, as its not easy to predicted 70 years in advance), some man-made catastrophe (also unlikely, as this probably wouldn't give 70 years warning), an asteroid (easily predictable, yet with 70 years notice it seems implausible to me that no one would come up with a feasible plan to redirect the asteroid), or even an alien attack (no precedent to draw conclusions on, yet if they attacked just to destroy earth and let us get away, they're kinda douchey, aren't they?).

Whatever the case, the first, shell-shocked generation of adults might try and create some form of government that was familiar to them, if only to add some semblance of normalcy to their now destroyed lives. I imagine they'd form some sort of democracy in this case, as the only plausible way we could have completed this sort of engineering feat would be for the UN or some other entity to unite the world (or at least the build effort) under one government, and the only government that strikes me as least disagreeable to everyone is some democracy or republic.

It should be noted, however, that the most likely time for a despot to rise to power and create some fascist state would be in the beginning, I imagine. I also think that the first generation would be the ones to enact stringent population control laws.

If all the necessities for life are provided, though, and no one has any sort of poverty, its possible there won't be any armed conflict. Most wars nowadays are at least partially a reflection of human nature to try and collect/hoard limited resources. The only other thing that makes me think peace is possible is the fact that all these people will feel connected in their exile, and that may make them empathetic towards eachother-- similar to how you feel closer to your friends after some traumatic experience.

That connected feeling could go away after a few generations once the people are sufficiently removed from the apocalypse, but it might also linger subconsciously (similar to how countries that were Allies in WWII are still friendly-ish today despite being 2.5 to 3 generations removed).

I do think that 300 years is sufficient time to forget the significance of earth getting blown up. (I use the precedent of most people whom it may concern not caring about the American Revolution, despite only being 225 some odd years removed. For instance, 300 years is like the difference between the latest crusades and Columbus "discovering" the new world, or roughly the amount of time it took the Israelite nation to grow from 70 people to 2.5 million while in Egypt).

Anyways, it would make for several very interesting novels, if people haven't written about this already.

My bet is for a near utopia at the beginning which turns into something of a dystopia towards the end once people start wanting to buck population control laws.

[Nuke]

some things:

its a ship. the government is going to be the captain and officers. though you might use the pirate ship model, where the captain is voted in by the crew and can be deposed by the crew at any time. you also dont want a bunch of passengers making these decisions, as they do not have the training neccisary to understand who would make a good captain. you might have a democratic civilian leadership that is independent of the crew structure, this would have the job of keeping the population happy while the crew have the job of keeping the ship safe. the economic model will probibly be communist or possibly socialist to eliminate inter-class conflicts. rationing will be how goods are ultimately distributed. it will be an engineered society.

population control is going to be critical. if you somehow create more humans than you can feed, you are going to have to resort to cannibalism. too few and you will have an insufficient workforce to maintain food production and keeping systems functional. so population control measures will need to be taken. so not only will you be limited to how many offspring you have, in some situations you may have a quota (to fill yourself or transfer to someone else).

workforce is going to need to be maintained at an optimal level. priority will go to filling essential jobs first, and personal choice second. so you might not get to choose your occupation aboard the ship. you will of course be placed in the available job you are best suited for, and would be required to stay there. because of the resource cost to retrain someone. traditional education will probibly be replaced with an accelerated education, you might do in 8 years what normally takes 12 (by setting people into their job early and eliminating unnecessary classes), then go through an aptitude selection process followed by vocational skills training or an apprenticeship for your job, depending on skill level and training required. unskilled labor could enter the workforce by age 16 and skilled workers could be ready by 18 or 20.

[kiwiak]

Anyways, it would make for several very interesting novels, if people haven't written about this already.

Can someone provide us with titles of interesting books in this topic? Life on board of generation ships, evacuating earth etc

Few years ago, i readed interesting novel by Arthur C Clark, about moon colony that accidentally become last stand of humanity after Nuclear War, barely managing to survive after being cut from any earth support.. I think its somewhat related to topic.

[Nebur Wolf]

Let's suppose we're taking sane humans into the ship, then crime wouldn't be a problem. People tend to turn to a crime-dependant life when they lack something. In this ship they'd have food, shelter, fun and people to socialize with. So I guess all the basic needs are satisfied. To prevent boredom, they'd need something to distract themselves, to challenge them in a physical and psychological way. I suppose current technology could already be used to challenge these people continuously.

So next "issue", would be quarrels/fights, which I think could be fairly common by people misunderstanding each other or saying something a bit more mean and not controlling themselves (in words and actions). If people nearby would help to end the fight, then it wouldn't be a problem. This really depends on the mentality of people in the ship.

Probably one of the biggest issues would be people abusing their available resources. So unless everyone in the ship(in 250k people I think it could be hard) would know when to stop drinking, eating, or doing any other thing that someone can get addicted to, that could become a problem. Unfortunately I don't think people would make it to Earth mk2 without control and rules.

So actually a militarized "way of life", just like Themohawkninja said, would be best. The chain of command would help maintain people in their places not do anything against the rules (they'd be sent to a court otherwise). Also they'd be kept busy with useless work(when there's no war, keep them busy). Of course that wouldn't prevent everyone from making "mistakes", but I guess it would be the lesser evil (if I could say so).

Still, I'm just supposing this ship would have a society like the ones we have on earth.

[Javster]

For entertainment, just give them a copy of KSP each

Seriously though, maybe cryostasis would be a better idea than everyone awake and doing stuff.

[Drunkrobot]

Seriously though, maybe cryostasis would be a better idea than everyone awake and doing stuff.

This scenario is assuming that cryostasis couldn't be mastered to the point where an entire colonization force could be frozen and sent on an automated ship to a nearby star, without anything going wrong. (Dying in their sleep, the ship breaking down after 300 years without maintenance etc), so a sleeper ship is out of the question.