Imagine a somewhat near-future time in which earth is colonizing other worlds. We have space elevators and manufacturing factories in space to produce colony ships & supplies, and are shipping people out to another world. We do not have FTL transport, though we do have FTL comms.

We have identified, via probes or some other system, the most hospitable worlds, though we will obviously need significant infrastructure to be able to survive on even the most hospitable worlds we could find.

We will send a colony ship. We send additional ships on a regular interval with supplies until the colony reaches a level of self sufficiency. Presume this process has been done a number of times and we've figured out a relatively efficient process for doing so.

Roughly how much money and time will it take before a colony is self sufficient? by self sufficient I mean not only that it can survive without additional supplies, but has sufficient infrastructure to be able to grow and expand, and produce supplies necessary to do so, without further help?

  • $\begingroup$ time 2+-1 years on arrival, cost 0. $\endgroup$ – MolbOrg Jun 21 '16 at 1:15
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    $\begingroup$ I honestly don't see how this can possibly be answered. Cost is a relatively arbitrary measure of difficulty. Time depends totally on when you start counting from (launch of first ship? arrival of first ship? arrival of first human settlers? how long does the trip take? ...) $\endgroup$ – a CVn Jun 21 '16 at 8:05
  • $\begingroup$ and it depends upon way too many factors (where it is being established - environmental factors, how many people are in the colony, how much resources are provided at colony launch, what are the purposes of the colony, is the colony being resupplied, etc.). In order to write a reasonable response, you'll need to very tightly constrain this problem. $\endgroup$ – Jim2B Jun 21 '16 at 12:52

There is no hard and fast answer to this question. It heavily depends on the size and geography of the planet, the technology level of the pioneers, the population of the pioneers and the resources available on the planet. Here is some explanation:

Size And Geography Of The Planet

Wrong levels of gravity are a bummer. We humans, are very fine tuned for life on Earth. And our solar system is exquisite (so far) in the sense that it contains very small planets. It is very likely that there are millions of rocky planets like ours, at the right distance from the parent star. However, since you have not established the size of your planet, I would treat it as an unknown variable.

For planets with lower or equal gravity to Earth (something between Mars and Earth), we can cope very well. For planets with higher gravity, we would face a host of problems. We would require larger muscles, thicker bones and larger lungs. This means the pioneers will be unable (or hardly able) to harvest any natural resources available on the planet and would have to subsist on supplies from home planet until evolution takes its course (or we genetically enhance our babies) and we have a sturdier generation which is able to easily survive and thrive on the planet.

So in case of gravitationally unfit planets, the investments will have to continue until suitable humans are produced. This might take as less as 25 years (if genetic enhancements are available) to as long as 50,000 years (for natural evolution).

As for the geography, a lot of investment will be required for a planet with no readily available water supply. For a planet where saltwater/seawater is readily available but there is no freshwater, major investments would be required for turning seawater into drinkable water (which would also be used for farming).

Technology Level Of The Pioneers

A higher technology level would require lesser shipments later on. By higher technology level I mean that the technological objects in usage are very dependable, durable, have high efficiency, can be run on solar energy and are miniature sized.

Obsolete and decommissioned pieces of technology require replacement, which translates to shipments (investment). Large sized technological objects (water filter plants etc) are easily damaged (in the long run) by sunlight, rain and other natural processes.

Population Of The Pioneers

This should be simple. A smaller number of people are not a good idea for populating a planet. The resultant population would be inbred and be very susceptible to epidemics. If initially a small number of pioneers are landed on a planet, later more missions would be required simply to provide more genetic diversity to the pioneer population.

Resources Available On The Planet

With an advanced metallurgy plant shipped with the pioneers and a high content of metals in the crust of the planet, it would be easy for the pioneers to create their desired metallic objects. Similarly, if a planet has life on it and earth-like trees, it would be very easy for the pioneers to harvest as much wood as required, to build extensive housing and other structures.

This again relates to the technological level of the pioneers. The higher technological level they have, the easier it would be for them to harvest the natural resources available to them.

Final Word

In answering your question, I have assumed that you want the pioneers' generations to continue from the technological level of their parents. This is going to be a very hard thing. Without a proper society and all types of technological education and experimentation available to the next generation, they would not be able to grasp the scientific understanding of their parents, let alone build on that foundation.

Maybe the best idea is to send a group of pioneers on a very earth-like planet and let them start (technological) evolution all over again? Then send in enhancements once in a while (once every 30 years) to speed up the process. Build libraries, set up schools, colleges and universities, laboratories ... and have another, cleaner, purer earth with all the beauty of art and technology, but no problems of pollution, wars, violence and bad governance.


This question is really not answerable without a lot of assumptions. A society with the ability to create Von Neumann machines can essentially do this for zero cost, with the only time limitations being the period needed for replication (by specifying the "doubling" period of the Von Neumann machine, you can essentially answer the question using the compound interest equations).

OTOH, if society has somehow managed to achieve starflight but relies on manual labour for religious or social reasons, the answer is essentially infinite time and costs.

The other limiting factor is how much energy is going to be available. The maximum is the energy output of the star, but since no process is 100% efficient, there will be conversion losses which limit the total amount of energy that can be utilized.

Combining the two facts suggests that a single Von Neumann machine is sent ahead of time with instructions to use the local resources to multiply and then convert matter into a free flying swarm of solar energy collectors to create a Dyson Sphere. The energy powers ever increasing swarms of Von Neumann machines which rapidly terraform one or more planets and moons preparatory to human settlement. As a bonus, once the project is complete, the Von Neumann machines can then be dispatched to nearby stars to repeat the process. It is estimated that even fairly slow moving Von Neumann machines would be able to transform the Milky Way Galaxy in something like 10 million years, a short period of time compared to the billions of years of stellar life or the formation of the Galaxy itself.

The fact that this has not happened (so far as we know) would seem to suggest that we live in an empty Galaxy, and gives rise to the Fermi Paradox (where is everyone?).

  • $\begingroup$ The fact that von Neumann machines have not transformed the galaxy could also be an indication of that von Neumann machines are actually not a practically implementable construct, but just a theoretical idea. If there is intelligent life elsewhere in the galaxy, and that life has a desire to reach for the stars, and have conceived of von Neumann machines, and we don't see such machines (or their results) everywhere, that could be a sign that such machines simply cannot be built because of some as yet unknown technological or physical limitation. $\endgroup$ – a CVn Jun 21 '16 at 8:00
  • $\begingroup$ @MichaelKjörling - or perhaps the rest of the galaxy just has very strict anti-spamming laws? I always considered Von Neumann machines more akin to spam than colonisation! :-) $\endgroup$ – DrBob Jun 21 '16 at 9:16
  • $\begingroup$ @DrBob Or littering laws. $\endgroup$ – a CVn Jun 21 '16 at 9:36
  • $\begingroup$ All these things might be true, but we know that von Neuman machines are possible in principle since living organisms are essentially von Neumann machines. And many of the incremental improvements in economic output, standard of living etc. that developing von Neumann machines provide make powerful incentives to keep going down the path and fully develop them. $\endgroup$ – Thucydides Jun 22 '16 at 2:45

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