A ship is sent through a wormhole to an unknown planet to create a sustainable colony. The colonists know that they won't have further contact with their home planet - this is a last ditch effort to save the species.

An earlier question gave the number of colonists required as being anywhere from 80 to 300, but what about technical skill and knowledge? What professions and experts would you need to keep the colony alive? Medical personnel, engineers/mechanics, and botanists/biologists are the groups that immediately spring to mind. You'd also need a leader in place to keep everything running. What other important positions and skill sets would be required? Disregard the pilot and crew of the space ship for the moment - who would they need on the ground?

The technology level of the initial colonists does not have to be sustainable. They can lapse into a pre-industrial level society.

  • $\begingroup$ Does sustainable mean they continue breeding on a basal level? Does it mean they continue living? Does quality of life have anything to do with it? $\endgroup$ Commented Feb 22, 2015 at 4:31
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    $\begingroup$ I think you need about 4500 people to have a large enough gene pool for the group to survive long term if there is not going to be any fresh gene reinforcements from 'home' $\endgroup$
    – bowlturner
    Commented Feb 22, 2015 at 13:41
  • $\begingroup$ "Sustainable" means that they survive and continue breeding, growing the population. $\endgroup$
    – CoolCurry
    Commented Feb 22, 2015 at 16:43
  • $\begingroup$ Do the colonist know where are they going (and the local conditions)? If they do not, the most sensible approach is a high-tech "bubble" (hydroponics, nuclear power, etc.) and, slowly, research how to use the environment. If they know the environment beforehand and it is close similar to Earth, they could try with farmers/hunters. $\endgroup$
    – SJuan76
    Commented Feb 22, 2015 at 20:45
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    $\begingroup$ Just because I see both answers other than mine are trying to get at the genetic diversity question, you don't actually need a really huge group to avoid population bottlenecks. Biology.SE also takes this one on, with the implication that CoolCurry's original colony size of 80-300 people is probably okay. (But the Interstellar route with frozen fetuses means you'd be getting more people's genetic material out, so there is that.) $\endgroup$ Commented Feb 23, 2015 at 3:42

6 Answers 6


You'd absolutely, positively need farmers. Possibly a lot of them--at least a significant portion of your colonists would need to be farmers primarily, or have some kind of agricultural and/or animal husbandry skills in addition to their primary skill-set.

Food is paramount to survival, and if this is a last-ditch survival effort that requires the colony to become self-sustaining fast, you don't want to rest all your hopes for food on equipment that will eventually break down or wear out. This means your farmers need to be actual, dyed-in-the-wool farmers, not just "guys who can drive a tractor or run the autoharvester".

Survivalists (hunters, woodsmen) of some kind would also be useful in the "food" (and shelter) capacity. While your botanists and biologists will be able to tell you what on the ground is safe to eat, you need people accomplished in hunting and foraging to get it for you. Additionally, they'd want to pass as much as they could of their skills on to the other colonists, which improves everyone's survival chances.

And, in addition to engineers and mechanics, you'd want architects. Gotta be able to set up enough homes for your colonists once you've run out of prefab structures. (ETA: Burki wisely points out that civil engineers are probably better than architects; we don't want really snazzy homes, just working shelters.)

More than anything, you'd want people who can do much more than just one single specialized job--you want jacks-of-all-trades. If the people sending out your last-ditch survival effort have the leisure to pick, they'd want to choose colonists who have multiple useful skill-sets that span the range of what's needed. A botanist who also has experience farming or an engineer who's also an outdoorsman would be the perfect kind of person for this. (Unfortunately, they'd also be comparatively rare, if the current trend toward specialization in our own society is anything to go by.) (Thank you to PipperChip for pointing this one out!)

Interestingly, while most people remember her books for the dragons, Anne McCafferey actually does a pretty fair job in Dragonsdawn of showing just how much would go into setting up a self-sustaining colony that's meant to exist at a roughly pre-industrial level. Granted, some of her ideas about logistics (how much arable land it takes to feed GIANT FLYING MACROPREDATORS) are kind of silly, but she recognized that pretty much everyone would have to shift from highly specialized job roles like "botanist" and "engineer" to more generalized, mostly agrarian skill sets over the life of the colony.

  • $\begingroup$ While these are the important jobs, what about people who do both? A botanist who knows how to forage, for example, could be more useful than a single botanist and a single forager who only know their tasks. I feel addressing the value of multiple sets of skills in individuals would be paramount in this situation. $\endgroup$
    – PipperChip
    Commented Feb 22, 2015 at 4:30
  • $\begingroup$ @PipperChip Oh, absolutely. With the original set of colonists being so small, you'd need to have people who can do more than one thing along. I'll add that to my answer. $\endgroup$ Commented Feb 22, 2015 at 4:32
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    $\begingroup$ Right. So, ironically, the ideal makeup for a space colonization team is about 90% Amish... $\endgroup$ Commented Feb 23, 2015 at 22:57
  • $\begingroup$ @RBarryYoung If riding out there on a spaceship weren't too hochmutig in the first place, I'm sure they'd do great at it. Although they are an example of a highly inbred population you probably would not want to seed a long-term colony with... $\endgroup$ Commented Feb 23, 2015 at 23:11
  • $\begingroup$ Small comment only, but still: i would suggest civil engineers rather than architects. You don't need smart room setups, interesting ways of arranging light and room, you do not need anyone to coordinate the different specialists. all you need is a robust shelter. $\endgroup$
    – Burki
    Commented Feb 24, 2015 at 12:38

Short answer: a fair number of (mostly) youngish women


Without a real good Earth ecosphere match, you're going to have to be able to run an industrial civilization.

You can't go caveman if there's nothing to eat. And there's no reason for there to be plants or animals that've evolved to be edible/useful/productive for aliens (ie: Earth humans). Or for Earth imports to be able to out-compete species on their home turf, in the ecological niches they've spent billions of years optimizing for.

Unless you know that you're only going to be competing against blue-green algae/or whatever has made you a nice oxy-atmosphere - you better be planning on being able to sustain some level of technical civilization.

Because you are specifically not taking enough people to wipe out a planet, and terraform it to be Earth compatible.

As per habitable planet considerations, you're going to a world that has life, so there is free oxygen. You're not going to farm the dirt (or even have dirt if it's just oxygen-causing soupy seas), unless you have high tech tools.


MVP aside, I think you're going to want 400 people/women (and preferably a really huge set of frozen sperm and eggs - and the ability to keep them on ice and do IVF, if not artificial wombs (might be doable right now, if laws were less draconian)).

Btw, unless there is a reason, you should probably be taking mostly (90%? - ie: 40-80 backup sperm donors, preferably with different, surgically implanted second (and third!) testes) pregnant women as your colonists. Preferably varying durations of pregnancy so they're not all due at once. Preferably using sex-selection techniques to ensure 75-90% female fetuses for that first generation, also with both wide genetic diversity and narrow.

In the West at least, there are usually women trained in every field. Very few fields have only male practitioners. You'll preferentially pick those, and you'll train those (if there's time).

Civilization maintenance is another post, or more on this one later.

  • $\begingroup$ "Naturally, they would breed prodigiously, eh? There would be much time, and little to do. Ha, ha. But ah, with the proper breeding techniques and a ratio of say, ten females to each male, I would guess that they could then work their way back to the present Gross National Product within say, twenty years." $\endgroup$ Commented Feb 24, 2015 at 1:44
  • $\begingroup$ I took from "the technology does not have to be sustainable" = "it doesn't need serious terraforming to have human-edible crops there, and/or the biota are already safe and delicious". But this is a better general answer, definitely. $\endgroup$ Commented Feb 24, 2015 at 4:59
  • $\begingroup$ @plagueheart Oh yeah, totally fine if the biota are safe, delicious and non-threatening, and/or Earth crops and animals can out-compete the aliens. But, would you want to bet your species on that? We've not even done a good job of exploring our planet, with tons of time and trillions of eyes on it, over 100s of thousands of years. I remain unconvinced when people say '(some humans) surveyed a planet'. Not convinced that humans shouldn't stay in space and build up numbers, either. $\endgroup$
    – user3082
    Commented Feb 24, 2015 at 7:35
  • $\begingroup$ @serban At year 21, given some assumptions, I'd only be producing 357 girls, and with a total female population of 2,502 (overly optimistically having zero deaths in childbirth, accident, illness, etc, etc - and only 5% non-fertilization/spontaneous abortions). Male population is a little less than that, but since more males are born than females, and nobody's reached end-of-life, might be getting closer to parity. Assumed some menopause / medical problems started knocking on wombs after 5-6 births, and/or reaching age 35-40 for women. Things are looking up from there; 14 & pregnant. :P $\endgroup$
    – user3082
    Commented Feb 24, 2015 at 7:53

Teachers. So that knowledge is transferred to coming generations. Anything you would want future generations to know - language, mathematics, physics, history etc. no point in sending technical expertise if the knowledge isn't transferred, and without the basics it's hard to be become an expert.

  • $\begingroup$ Contrarily, many skills have been passed on using apprenticeships, and on-the-job training. All of the Roman engineering was done this way (which is part of the reason we have problems with it, since there weren't a lot of textbooks running around). And we do have textbooks, so when people do want to have teachers, there are things to train teachers, as well as books to teach subjects. I think any grad student will make an adequate teacher, until there's enough economic surplus and time surplus to fund dedicated teachers. $\endgroup$
    – user3082
    Commented Feb 24, 2015 at 8:07
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    $\begingroup$ Pedagogy is rather important, especially for the early stages. While technical skills can be passed on with on-the-job training, it is not at all obvious what is the best way to teach them the basics of language and mathematics so they can best make use of the training. $\endgroup$
    – March Ho
    Commented Feb 24, 2015 at 11:02

It would be difficult to make a sustainable colony because specialization would be lacking. Our current earth is only possible because we have 6 billion people cooperating to produce things. Where you would have the greatest problem is advanced technology or technology involving large pieces of equipment and capital investment; that would mean computer technology, mining, farming and power generation would be the biggest problems. Making computer chips and power generators without large teams of specialists and resources would be difficult. Also, how would you mine metals and new materials? Mining is very capital and labor intensive. Without prospectors and mines you would have no way to get new metal. Mechanized farming is only possible with large factories making tractors and other complex farm equipment (harvesters, tillers, etc).

The immediate problem would be food production. Without tractors you will be in trouble. You can farm by hand, but it would mean virtually everybody would have to be a farmer or farm hand. This would be the situation of a small isolated community. They would essentially be reduced to subsistence farming.

Without a large infrastructure to support machine making (steel, oil/coal, chemicals), you are basically stuck living like a primitive caveman just to get enough food. You would need many thousands of people to support minimal mining and blacksmithing operations to get out of that.

Let's just back up a little and ask, what would we need to do have a 1000-person colony that would not be living like cavemen or eskimoes (hunter-gatherers)?

First of all you would need to bring materials and equipment: rubber, tool steel, glassware/optics, machine tools, generators and motors, computers. Lose any of this stuff and you are screwed. The biggest bulk would be the machine tools. You would need at a minimum: a lathe, milling machine, grinder, arbor press, hammer forge, anvils, dies of various kinds, files, gearing, abrasive wheels, etc. You would be talking several truckloads of machines at a bare minimum. You would need at least 50-100 people to operate and maintain all these machines. You would need another 50-100 people to focus on mining, primarily iron which you absolutely must have a source of.

You will start to run into trouble with tooling. Your cutters will wear out and you need tool steel to replace them. That means you need nickel, chromium, manganese, and moly, if not vanadium. Getting these materials without big mining operations would be problematic. For example, nickel tends to be a deep earth metal so requires a big operation.

You would probably need 200 of the 1000 to be doing nothing but farming. You need 50-100 doing irrigation, water supply and sewage. You would need about 50 people doing power management, which I guess would be water based. You would need another 50 or so doing pottery and container making. You would need another 50-100 doing fibers, meaning rope, cable, wire, gathering and making. Another 50 doing garments, gloves and protective gear. You would need at least 50 women giving birth and doing child rearing and another 50 teachers and trainers. Are we running out of people yet?

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    $\begingroup$ The last paragraph of the question said that I was fine with them living like cavemen. They don't need to be at all industrial or technological, just alive. $\endgroup$
    – CoolCurry
    Commented Feb 22, 2015 at 18:05
  • $\begingroup$ @CoolCurry In that case, you don't need any technology at all. They can live like eskimoes, living off of animals. Even a single family can live like an eskimoe. $\endgroup$ Commented Feb 22, 2015 at 18:06
  • $\begingroup$ FYI: Inuit - also disagree with your setup... $\endgroup$
    – user3082
    Commented Feb 23, 2015 at 1:08
  • $\begingroup$ @user3082 Inuit is just one language group. There are lots of Eskimoes that do not speak Inuit. None of the American Alaskan Eskimoes speak Inuit. $\endgroup$ Commented Feb 23, 2015 at 1:41
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    $\begingroup$ Only the Yupik of Alaska don't like being called Inuit. The rest of the Alaskans are fine with Inuit. Canada, Greenland, etc, are all Inuit, and view Eskimo as a pejorative. $\endgroup$
    – user3082
    Commented Feb 24, 2015 at 8:03

I added edits how to handle situation in fairly hostile planet (no immediately edible animals or plants), and with fairly limited crew size.

ALL colonists would be young women PhD biologists (with few mechanics/electronics engineers added) in their twenties and early thirties. Smartest ones, very healthy, genetically screened. Few genius teenagers, to stagger fertility (after age 40 fertility diminishes and chance of genetic diseases increases dramatically). And many (tens of thousands) samples of frozen sperm for later, to maintain genetic variability. Would not make sense to waste such limited space on men, if you can grow them up later - when you are sure you can feed them.

Not sure why and how is your limit on number of colonists: Is it total weight of the cargo in spaceship? Because if weight is the limit, it could make sense bring less crew but more cargo which would help to establish colony faster (because cargo does not need food and life support during the flight). And spaceship can provide life support after landing too, for exactly same number of crew.

If planet has breathable air, it has some life (which created oxygen), and likely some kind of plant and animals - at least algae and fungi. So you can assume you can harvest such resources for needs of your colony, and consume them after some transformation. From original post, it is hard to guess how different the biology of host planet is, and how much transformation will be necessary.

Depending on natural resources, you can support such small population by hunting/fishing (which require easy to gain skills) for first decade (kids don't eat much - spaceship can provide for same population), while working on developing basic industrial technologies. You need also a way to explore planet fast, to land in a place with lots of natural resources. Your aim would be resources for steam age technologies. Coal and iron, next to reasonably fertile plains.

You would need to observe weather and seasons, and be ready to relocate few times - which should not be too hard, because for first at least decade you would live in spaceship anyway.

Taming animals also can be established quickly: experimental domestication of silver fox done in 50 years (20 generations). You need easy source of food, like insects or fish.

You will include also huge library, so young crew-members can learn from experience of others on Earth, and not from own mistakes.

Depending on how much time you have, you may even try to run simulations of such settlement on Earth, with colonist trained in developing steam-age technology from scratch: outside world provides them raw materials, but they need to figure out how to build needed tools, and manage community and not to kill each other. And they have whole tool-building factory on spaceship (and lots of metal). So elder colonist would be best veterans of such training, who did such boot-up few times, and youngest at least once. So they could be preparing for such mission for a decade or more. If you have few decades, you can set up whole culture about that: mothers training their daughters to be experts in necessary technologies, preparing lab technologies which are automated and easy to repair, etc.

Think about Ender's Game Room, but for female double major PhD biologists and mechanical engineers. If you are selecting only one of hundred million, you can be very picky - and people will be motivated to learn necessary skills.

Farming and hunting is a basic skill which any person preparing for such mission can pick relatively quickly. Plant biologist will naturally cross-train as farmer, and animal biologist or geologist as hunter. You need also "tool people" like mechanical engineer, builder, miners, chemist. And medical personnel, especially gynecologists and psychologist, including children psychology. All women of course.

If you have really long time to prepare, many can be children who were born and raised in such simulation camps on Earth. Raised from sperm of men who have very gifted daughters, by teachers trained for such situation (no male examples).

There is a danger that women on such colony would like life without men, and would not raise any until there are many thousands of women - planet of Amazons indeed. :-)

In worst case scenario, none of local lifeforms are usable for humans, and you need to develop ecology. You will need more biologists (or more time). They will have to design bacteria which can digest local lifeforms and grow and be fed to higher life forms usable by humans, like: algae, fungi, then insects, chicken. It will be long slog, might take several generations of (all female) researchers to develop necessary technologies.

During this time, colony would be supported by original life support system from spaceship (powered by solar energy), and would not be able to grow numbers beyond what life support system can feed.

So if you are very unlucky, and very limited, you have crew of say 100 female biologists (few cross-trained in medicine) supported for several generations ONLY by life support from spaceship, trying to figure out how to use local life-forms to sustain humans. No men needed, focus 100% on research and training next generation. Women get artificially inseminated to born new generation of girls (one replacement girl each) to train them and continue development of ecology until they figure out what grows and can sustain the colony. Likely girls will have to prove themselves to be smart and team players very fast (IQ test by age 6), or be disposed of (used for human experiments) to be replaced with more promising sibling. It will be very brutal, but such planet will not be a place for weak - or even for average. Until we can feed everyone, we can afford to feed only the extraordinary - or die out.

Only after basic farming is established they can consider increasing size of the colony beyond what spaceship life support can provide for, and spend resources on developing additional technologies (after learning them from ship's library), mining resources, building outside structures, growing the colony.

Even then, you would want to try local food only on few volunteers (human experiments again) to see longer-term consequences before you commit whole colony to new food. You have no margin or error to i.e. local food in some way causing birth defects after 20 years of consuming it. So likely young population (before and during fertility) will stay on original Earth food for even longer, after older (past 40) will try to "go native" - and possibly suffer the consequences.

Genetic diversity is not a problem at all, you may have several thousand samples of sperm, to start using in different generations. If you have time, you can even select fathers by ability and skill: science skills, engineering/manufacturing skills, fierce fighter skills, as expressed in their daughters. With frozen sperm, problem is not genetic diversity but sustaining life in the colony.

If you can have some experts in hibernation, that could help: you will thaw them when you need expertize, and refreeze then in between. Will be extremely harsh world, with very strict morale about living only to contribute to survival of the colony. No slackers.

You need defense to protect your colony. Best weapons would be something where you need to add just energy (from solar) and not chemicals (which you need to bring with you [expensive cargo] or mine and manufacture locally [distracting you from survival]. Mechanical catapults using local rocks fits the bill.

You know it already, but with such stacked deck, you have VERY small margin of error, and any small mistake might wipe out your colony. Sending multiple spaceships will make much sense. it will also limit consequences of choosing wrong landing place - because even if relocation will be possible, will not be simple nor easy nor cheap.

Absolute minimal limit might be as little as maybe dozen female biologists/engineers, with spaceship capable to support them for many decades until they will develop ecological way to support bigger population from local resources. Really tough. Could be good story.

  • $\begingroup$ You are assuming a biologically bountiful planet fully stocked with fish and fox (which are identical to those found on Earth). If there is life on the other planet, it will not be identical to that found on Earth, and most likely will not be biologically compatible (toxic to eat). $\endgroup$ Commented Feb 27, 2015 at 16:52
  • $\begingroup$ That's why I have plant and animal biologists: to find out how to use local resources. OP did not specify how much is known about target planet. If nothing is known, they will have to build life support for ALL population, including food and oxygen. TAHT would be substantially more difficult task. $\endgroup$ Commented Feb 27, 2015 at 18:43
  • $\begingroup$ @pluckedkiwi - OK I added very restricting limits on host planet biosphere. Even harsher limits that in your own answer. :-) $\endgroup$ Commented Feb 28, 2015 at 3:17

Since an Earthly biosphere wasn't specified, I would say a closed ecosystem and the skills and materials needed to run such a thing would be the absolute minimum.

Explorers can exit the "bubble" to discover what resources are there (so you would need geologists, prospectors, biologists and so on to catalogue the resources on your new world). Finally, trained technicians who understand mining, smelting forestry, agriculture and all the other trades needed to utilize these resources, so you would need a fairly large colony (to contain all the skill sets), some form of advanced database and learning system to teach the people new skills if you have a small population, or some form of advanced AI to teach people and run machines remotely would also be needed. If this seems pessimistic, consider the essay I, Pencil by Leonard Read. The accumulated knowledge to make a typical pencil in the modern world is spread among so many different people and different places (gathering raw materials, the logistics chain to get them to the factory, the various skills needed to convert the raw materials to a pencil and the logistical infrastructure to get the finished pencils to market) that no single human being knows all the steps needed to create a typical pencil and get it to the end user.

Of course, you could also go the other way and send an enclosed ecosystem as a space colony and enough technical equipment to mine asteroids and moons to replicate the bubble as many times as you like, although once again a vast pool of either people or knowledge would be needed. Go straight to a space based civilization and ignore the planets (or leave them for later). If you can do that, the reasons for leaving the initial solar system might well be moot, unless you have to leave because your Sun is going nova or the solar system is being bathed in a gamma ray burst.


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