Friday, July 13, 2012

The Ark At Launch

Consider a generation ship at launch. A ship in pristine condition - perhaps a little too clean, and with a nimbus of loose parts around it. Most likely in Earth orbit, to facilitate mass evacuations. Maybe tied to a beanstalk, or at least in close proximity.

The Ark is shaped like an inverted umbrella - one whose struts and canopy were reversed in a storm. Engine faces down, Habitat domes face away from the engines.A small Bridge section rises on a mast through the bowl-shaped canopy of domes.

Its crew is the best of the best. In fact, there are several crews. Some will be in hybernation, held in reserve for an emergency, or to ensure retention of key knowledge and skills a thousand years into the journey. Some will be just kids - the ship will be their Academy.

The supercargo is from many different nations and cultures. Habitat domes are perfect for this purpose.

  • 55 Habitats per parasol wedge x 6 wedges = 330 habitats
  • Each Habitat is 50 miles across
  • Bounce tubes connect domes to each other and allow for rapid transit between Habitats

The cultural diversity of the supercargo may be because in the lonely hour of the last instance, altruism prevails. Or it may be out of some Dawkinsite enlightened sense of self-interest: memetic diversity may help ensure the survival of at least some human genes across the generations.

There will also be debates about whether to encourage cultural seclusion (preserving what is unique and special about different nations and groups) or whether to encourage oikoumene - a world-culture for the world-ship. Will each dome be a hermetically sealed universe, or be one part of a world without end?

At the start of the journey, the Ark will be humankind's last best hope. Can it remain so on its long journey?

All images from The Starlost Compendium.


The Ark at Launch: It does not make sense to use ordinary spacecraft statistics for a space ark that is hundreds of times larger than ordinary spacecraft. Instead, let's imagine the Ark  by specifying it's level of Technology, Environment, Resources, and Aspects at launch time.

Imagine the Ark as a self-contained world.

  • Technology +1: Exploiting the system (the Ark can complete its construction in this system and exploit the resources of any system it visits)
  • Environment +4: Many garden worlds (all 50 miles across)
  • Resources 0: Sustainable (Each dome habitat is self-sufficient). An internal economy has not developed yet.
    • Humankind's last, best hope
    • Built to last
    • Worlds without end - at least 330 of them


  1. Interesting choice in design. this should work nicely for an RPG setting. The Starlost is one of those 'lost' TV series that have had a lingering influence, even after their demise. There is supposed to be a comic book adaptation of Ellison's original script. But it's unlikely we'll see this series revived.

    The inside-out umbrella configuration seems like it would make sense looking up from the planetary surface, but it starts to get problematical once you consider how it might respond to rotation, acceleration, etc. This Ark will require a lot of maintenance drones, and maybe a good bit more reinforcement...possibly they use some sort of force-field tech like the Trek ships are supposed to use (not to get too hand-wavium)? Or maybe they have access to some sort of Nivenian-material like scrith?

    Nice post! We're looking forward to where this leads...

  2. I readily admit that this choice of design is nostalgic (even if the design is a radical reworking of the original Starlost design). I know the show was supposedly horrible but I loved it as a kid.

    I ran the physics of this design past someone who is fairly knowledgeable about realistic ship designs; her primary concerns were with the exposure of the habitats. You want to use a hollowed out asteroid for maximum protection of humans.

    That being said, the plus of this design is that if the ship can maintain a constant 1 G acceleration, we don't have to worry about pseudo-gravity; we can have the real thing, at enormous energy expense.

    The notion is that the ship uses a Bussard ramjet with a very wide EM funnel cone that is nearly impervious to particles. Bova's design also has satellites stored in the engine area that can be deployed as needed to extend the funnel's area. Particles are funneled into the mainmast and thence to the engines, and thus particles at near C avoid hitting the Domes "behind" the EM funnel.

    Occasionally something will still get through... so we will have dead Domes. Fortunately spread out as they are, loosing one Dome is unlikely to kill the ship.

    Since generation ships go on long journeys, and since the design of this ship is fairly modular, my next steps will include:
    1) Writing up the T-E-R codes for the vessel at various points in its journey, keeping in mind the typical stages of life one tends to see with generation ships in SF;
    2)Creating a set of T-E-R codes to stat out individual habitat Domes, as well as other ship sections of interest.

  3. This is a really cool idea -- by modelling it with T-E-R, one could even have a system in a given cluster being modelled with a generation ship, that somehow is keeping its slipknots with it.

    Fun stuff.

  4. This is an awesome idea! So awesome that I'm going to set my next Diaspora game INSIDE an arc like this. Swap Tech for Order at generation and you can easily mod the Cluster Creation for Habitat Creation. Then set it some generations after launch and the story will write itself!

  5. @Jan: Do you have ideas for how you would quantify Order from +4 to -4? :)

  6. This is pretty cool. Gravity can be created by three dee printing a layer of protons on the 'bottom' of the domes using hydrogen given off by the sun. It means launching to orbit the star until proton layering sufficient to generate 90% earth gravity.

    I suggest centauri dreams forum for science on ram scoops. A proton at twenty percent light speed would ignite all matter on impact.