Building a Better Star Map II: The Leapfrog Effect

In my last post I began to improve the consistency of my star map. I will continue with that effort – and today I will attempt to figure out just how much “project leapfrog” might affect the expansion of human space.

Project Leapfrog was a project the Federated Nations ran in the late 23rd Century – building vast colony ships that were then sent off to “leap ahead” of the regular exploration and colonization.

Just as a basis, this is what I worked out so far.

Guesstimating a future frontline

Guesstimating a future frontline

Leapfrog 2, “Francis Drake”, founded Eureka in 2308 and was “discovered” in 2390.

We do not have fixed locations for the other two Leapfrogs, nor dates they were contacted by the explorers and colonists that followed them. I did place them on the original map, of course, but for the purpose of improving the map I can easily shift them around.

Only Leapfrog 1, 2 and 5 ever made it – the other three are “lost”. Let’s look at each, starting with Leapfrog 2 because we know most about it.

Leapfrog 2

The “Francis Drake” established a colony in 2308, after a travel time of 30 years. I have not designed the system yet, but for the sake of the map design let’s assume they landed on as near-perfect a world as they could find. You don’t travel 30 years to land on a Hell world if you have the choice.

We also do not know how many people these ships carried, but they were massive – 10 years construction time – and you don’t send such a ship out with a few dozen people. Let’s assume they carried 1000-5000 people plus all the equipment they could possibly need.

Population growth – It seems the highest growth rate Earth experienced was 2.2% – and currently it’s down to 1.1%. If we assume that a colony actively encourages people to have kids, we can probably assume something along the lines of the former value. Let’s round it up to 3% as an upper ceiling. So Eureka would grow like so:

Years Population Population
0 1000 5000
1 1030 5150
2 1060 5304
5 1159 5796
10 1343 6719
20 1806 9030
25 2093 10468
50 4383 21919
82 11288 56444

Looking at these figures, we probably want a base population closer to 5000 people than 1000 people. Is this feasible? Sure, if you can build hyperspace ships that carry four-digits numbers of passengers in cryonic sleep, then whether you send of 1000 people or 5000 people probably doesn’t make a big difference.

Infrastructure – How long does it take to build a society and an infrastructure that supports space travel? Even assuming you do not have to figure it out from the ground up, this is a major undertaking. I think that 50000 people aren’t enough – after all, some of them have to work in agriculture or administration, as teachers, cops, and so on. If getting back into space is the single focus of the colony, and given the advanced technology and know how it starts out with, they could probably get to the point where they explore nearby systems fairly quickly. Colonizing any on their own is probably out of the question unless we count small outposts.

For comparison, the Apollo program employed 400,000 people at its peak. NASA currently has about 18,800 employees. SpaceX employs 1800 people. Both are obviously dependent on suppliers, but both are “low tech” space companies compared to Eureka. Building commercial airplanes – a much more mature “industry” – isn’t any less effort, though – Airbus employs 63000 people.

So, I think it’s safe to say that Eureka’s effect on human space by direct colonization was minimal. But having a supply base this far out was probably still a major boon; food, shelter, spare parts, rest & recreation facilities, and so on, probably helped a lot when the main wave of immigration hit the local area.

Direct colonization – How large would a society have to be to be able to support space industry and even send out colony ships of their own? I do not have hard data for this – and can’t really imagine where to obtain it. A planet would probably have to have millions of inhabitants. At what point does the population of Eureka hit, say, 10 million without immigration? If the growth rate is a constant 3%, it takes 312 years if the starting population was 1000; 258 years if the starting population was 5000 – compound interest really starts to add up.

Leapfrog 1

The “Zheng He” was launched in 2277, and founded Chasm in 2317. On my original map, Chasm is about 1500 light years from Earth, more or less directly Rimward.

If we assume the same distance, it would get contacted by the FN roughly by the time the FN collapses, in circa 2640. That’s 323 years – at 3% population growth, Chasm has 70 million citizens at this point – and has probably been colonizing nearby systems for up to 70 years! It might even be an exploration ship from Chasm that stumbles across a Federated Nations colony or ship, just so that Chasm can be dragged into the civil war. This works really well, since it creates a dramatic situation that is good for all kinds of stories.

Leapfrog 5

The “Leif Ericson” was launched in 2283 and founded “Secundus” in 2325. Secundus is, on my original map, about 1460 light years from Earth in the trailing direction – actually much closer to Home than to Terra. This is what I meant in my previous post when I talked about the Leapfrog project as a possible explanation for the elongated shape of human space.

Home might actually be a secondary colony of the Leif Ericson settlers.

At a constant 3% growth rate, Secundus would be at roughly 55 mio people if it is “discovered” at the exact same time as Chasm (with only 8 years less – compound interest doing its thing).

In 2580, when Home was settled, the population of Secundus was just under 10 million – or about the threshold I’ve set for “self-sustaining space industry and able to establish secondary colonies”. Perhaps Home – with such a “patriotic” name – was even the first colony set up by people from Secundus. I certainly do not see any reason why this should not be the case, and, speaking from a pure design point of view, interconnections are a Good Thing when you set up a timeline.

This would put Secundus within 100-200 light years of Home.

Finally – how much space would Secundus explore and/or colonize by 2643? Again, probably not a vast area – perhaps 300 light years, with colonies mostly closer to Secundus.

Putting it all on the Map

That was a lot of text – but now let’s put it all on our little map, shall we?

Updated map sketch with Leapfrog Missions

Updated map sketch with Leapfrog Missions

So far, so good. Because Empire will expand in the lower-right part of the map, the end result would probably again look “off center” – but this time with much, much less “blank” map space than before.

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6 thoughts on “Building a Better Star Map II: The Leapfrog Effect


  1. 5,000 might be a better figure genetically speaking considering the difficulties presented by repopulating endangered species and not getting inbreeding.

    I’m trying to think of what a spacefaring society would have to do culturally to have an expansion rate of 3%. Sure it doesn’t sound like much but even with advanced technology, you’re not living out a cushy life taming a planet. One of the first things that comes to mind is economic incentives but the US already has those in the form of tax breaks and the expansion is not that high.

    Some things that encourage having children historically are unsavory.

    Child labor is one, it does turn having a child into an economic incentive rather than a hinderance though.

    Illiterate women, it would take a bizarre or backward culture to re-introduce this but it could be interesting story wise.

    High mortality rate oddly enough. When you’re not sure your children will survive, you tend to have a few extra to make sure.

    Bans on contraception.

    A spacefaring society, hopefully an enlightened one, is unlikely to easily accept these conditions but what if some of them were white washed in a way to obscure them from being associated with their historic evils?

    For example, child labor is used by having the children control AI drones?

    Just some ideas.


  2. Thanks for the ideas Emmett. I agree that 3% seems high. The society (the Federated Nations) is an advanced version of ours, and while not perfect in its morale, is definitely not a step back either. So any “less savory” methods are out. There are still a whole lot of countries that have growth rates over 3%, but they’re developing countries, so low education of women, bad social insurance and so on are big factors: http://en.wikipedia.org/wiki/List_of_countries_by_population_growth_rate

    That list does seem to include immigration, but even so, I think that, for example, the ~4% percent figures are probably mostly natural growth.

    Actually, on a colony world – especially one “cut off” from Earth – children ARE an investment in the future, in a very basic sense of the word: Not enough children and the colony will fail completely! Doesn’t mean the kids will be used for child labor.

    I also think that you would not volunteer for such a mission if you are a person who does not want to have at least your 2 children per family.

    Medicine is another factor. We still have a – even if low – percentage of children who simply die. That might get reduced, but on an alien world accidents and diseases as well as hostile life forms might be a bigger problem too to balance that out. Fertility treatments or even artificial fertilization might be other things they would do, to help nature speed things up a bit. Nothing unsavory about that as long as it is entirely voluntary.


  3. I don’t think it’s a requirement to have these factors but they could crop up if societies are desperate.

    The reason I bring it up is that societies that make bad choices are often interesting from a story perspective. They introduce hard choices for the reader of a book or the player of a game.

    Not all societies should be making overtly bad choices in this kind of a world building experience but if a society really wants something to happen these choices sometimes get made by default rather than by some well reasoned process and it leads to a variety of settings. Otherwise if everyone makes “good” choices (or ones we would accept), then everyone makes the same choices and they’re all the same.

    Choices that are morally gray or black can still have mechanically useful outcomes for governments. With more and more frequency I hear of governments taking the “least bad option available.”

    Not that there’s any requirement to use this kind of world building.


  4. I agree with both of you. Check out damnspacebar next Monday for a post about this very thing. If you’re the pioneers of a new planet I would think that sending a bunch of breeders is just asking for trouble. I’m thinking heavily armed, well trained marines would be the way to go. If you cramp a few thousand civvies onto a boat and say “best of luck” it could quickly turn into a New World situation where the entire colony disappears, resorts to cannibalism, or just plain dies off (assuming no help from natives, of course). But then again I’m thinking of disease ridden European galleons, often illiterate colonists, and 15th Century tech to work with. In a future scenario people may know better what they’re in for and take the necessary means to prepare.
    Considering childbirth, if there were maternity droids (think Star Wars) to make the process easier, then the unpleasantries of child bearing could be greatly reduced, hence population growth. If inoculations are readily available you would lose far fewer children to diseases. The same applies to food stuffs, so the colonists would have much more free time to explore and establish bases that would otherwise be spent trying to cultivate crops in an alien environment.
    Another thought is, where do these pilgrims live? On the original ship? Are they send with the construction materials for building, or do they have to figure that out when they get there with whatever is (or isn’t) available on the planet? I think a generation ship that becomes its own fort/base on arrival makes a lot of sense. Think of C&C Tiberian Sun where the construction yard “unfolds” into everything the troops need to get going.
    A question: how much is known of these planets before the arrival? Is it like BSG where they can buzz and scan the planet in a Raptor? These generation ships could have such craft aboard to zip around on short recon missions both in space or on the ground.


  5. Emmett, you are totally right that morally ambiguous choices make for better stories. There’s gotta be conflict, or a world/setting is dull.

    Still, I think in this sort of scenario, you’d be totally able to find lots of volunteers – and they’d be very willing to reproduce as much as they can. There might still be restrictions or “weird setups”, for example to maximize genetic diversity, and so on. Increase in population means increase in productivity, and means increase in area covered – it all adds up increased survival rate for the society. Of course if the planet is not optimal, or somehow actively dangerous, things will be different; but for the purpose of this post the idea was to figure out “what’s the maximum?”

    If a colony encounters a catastrophe – even something simple like a massive flood that decimates the colonists – then yes, harsher methods may be enforced.

    Realmwright, these are vast sleeper ships travelling 20-30 years to get far outside of explored space. They don’t know much about their destination area – once at a pre-set distance, the on-board computer would try to find a suitable system and awake a sort of core crew from cold sleep. They’d do the final call on whether or not to colonize the world. Assuming planets that humans can live on occur with some frequency they would probably rather spend 1-2 extra years looking for one than settle on, say, a Mars-like planet.

    It’s not really a generation ship – it’s kind of like a sleeper ship, just with a much shorter mission; originally, sleeper ships were supposed to be STL. I think they would awake enough people to set up an outpost, then start waking up people and slowly ferrying them down. They’d leave the ship in a safe orbit and re-use it for exploration and/or further colonization – again, unless they run into trouble; in which case they might start cannibalizing the ship.

    The ship probably doesn’t have the capabilities for more than a few dozen people to live on it, although once the cargo holds are empty, it could probably be retrofitted with large hydroponics and so on. I also think that it’s probably a better idea to send out small fleets instead of single, massive colony ships.

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