Tuesday, March 7, 2017

Ezekiel's Wheel: The Escher of Habitats

     I described the type of centrifuge habitat used by the River-class transports as being a species of Winchell Chung's Ezekiel's Wheel.  I also described it as a maintenance nightmare, as anything that must hold pressure and spin is already a nightmare, and anything that spins on two axes is a nightmare squared.  Be that as it may, I also posited that when shaping an orbit that takes two years to reach your destination, high maintenance is not necessarily a bad thing - it gives your intrepid Astros and Espos something to do during that long trip in the black besides stare at the wall and go mad.
    Besides, It looks cool.
Observe the coolness.,
    The twin hab rings float in a gigantic globe of water.  This is for a few reasons.  First, the water is the "Fleet Reserve" tank of propellant for the Patrol Rockets, tugs, service modules and any other spaceraft requiring chemfuels.  Second, the water is a cracker-jack protection against ionizing radiation, including the cosmic rays that vex long-term space travel.  Now, this diagram shows that the globular water tank provides excellent protection fore and aft, but is lacking in the lateral direction.  We'll have to supplement the water tanks with some magnetic shielding - which is fine, as the forward hanger, conning tower and command module need such shielding anyway.  Still, it is to our benefit to put the habs in the water tank, for even more reasons.  How about thermal insulation?  The water tank will act as an enormous heat sink that provides even temperatures to the habitat sections throughout the long voyage to Saturn.  Then there's vacuum insulation.  Let's face it, RocketFans, while John Campbell was wrong about using the Dean drive to turn subs into spaceships, he was right about one thing - we know a heck of a lot more about building subs for long-term habitation than space habitats. And the habs we have on the River are actually easier to design than subs - they don't have to be insulated against sound, since in space, no one can hear you scream.  But in all seriousness, it is easier to plug a leak in a water vessel with a wedge of soft wood than it is in a rocket with a specially designed polymer that won't boil off or become brittle when exposed to vacuum.
     There is one other thing I wanted to speculate upon with the design of the Zekes for a space habitat.  I am, for various reasons, in favor of hub-less torus centrifuges - or at the very least, a torus that does not derive its spin from the hub.  The sheer size of these habitats, for example, would put enormous torque on the hub and whatever spokes connect the hub with the torus.  My usual dodge is to put wheels on the torus and have it trundle along some sort of track - As I've mentioned here and here.  But the Ezekiel's Wheel design, alas, makes this impossible, as the pods rotate in two axes.  My solution, I am happy to say, involves the clever use of another piece of nautical tech:  Azmuth thrusters.
The simple inclusion of these thrusters solves the torque issue by giving each pod its own propulsion.  The advantages don't stop there, however.  The propellers will stir up the water in the tank so as to keep the temperature even.  The propellers can generate thrust using only electricity, and lack the mass penalty of a flywheel. The direction of the thrust can be easily changed, which means that the Azmuth units may be useful in changing the orientation of the hab pods during the transition from rocket thrust to freefall.  And again, there is a certain cool factor.
     Speaking of cool factors, just what kind of crew would such a habitat benefit from? Astronauts, or Submariners?  The question is moot, as you'd need a little of both, but some of the culture of Submariners is sure to become part of the Astros' traditions in service among the River -class spacecraft and their militarized equivalents.
    But back to spaceships and deckplans.
    To the right are a couple of views of the habitat pods that will be inside our globe of water in our spaceship going to Saturn.  These are not small pods, as you can see - each deck is over twenty-five meters long and the smallest is twelve meters wide.  That is a lot of habitable volume.  And there are twelve of these pods; six per wheel, arranged in two counter-rotating wheels.  There are flexible tubular walkways connecting the pods to their rotating hubs, which in turn connect to the central hub.
     Even postulating that half the volume (six pods) will be taken up by hydroponics and plant gardens, There is a lot of space for a lot of people.  But who are they?  What do they do?  That, my dear RocketFans, will be the topic of Friday's post.

1 comment:

  1. That's a novel idea. Color me curious for the next installment.


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