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Old 01-02-2021, 07:23 PM
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Damraska Damraska is offline
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Asteroid Driver

For my third card model design project I intend to build an asteroid driver spacecraft in 1:500 scale. Very simply, an asteroid driver pushes on asteroids to speed them up or slow them down, thus nudging them into desired orbits. In the not too distant future, asteroid drivers will harvest asteroids from the asteroid belt and move them to the Legrange points near Earth and Mars, providing construction material for massive space engineering projects. Eventually, such ships will travel to the gas giants and even to the Kuiper Belt.

Asteroid drivers will use fusion reactors to achieve very high thrust with very small amounts of hydrogen fuel. Our solar system teems with water ice, locked up in craters and rocks of the moon, found in the rocks and perhaps underground on Mars, in comets, and in the ring material of the gas giants. Large processing ships will convert this water ice into various chemicals including deuterium for fusion reactors. This fuel will spur the creation of a vast array of inter-solar ships, some of which I intend to model.



My conjectural asteroid driver measures about 540 feet long. It includes two, one hundred foot diameter tokamak fusion reactors, six combustion chambers, six thrusters, one spun crew section, one static crew section, a gas collection ram, numerous hydrogen and oxygen fuel cells, and capacity for about 240 standard shipping containers. The spun section provides 15,700 square feet of space under artificial gravity, equivalent to about 8 moderately sized homes. I have not done calculations for the rate of spin but estimate this cylinder should provide constant gravity equivalent to one fourth Earth normal, enough to stave off the debilitating effects of prolonged life in micro-gravity.

I chose to model this ship because the design utilizes very simple conic and spherical shapes, well within my Blender capabilities. At 1:500 scale the finished vessel will measure about 13 inches (26 centimeters) long. This length may change as I adjust the design and add features. For example, my initial drawing does not include asteroid grabs at the front of the ship nor deceleration towers at the rear.

If things go well, I hope to complete work in Blender tomorrow and finish the entire project by the end of the month. Please keep in mind I must invent everything and am prone to delays, especially when I change my mind and redesign, so that number is probably very optimistic. Montgomery Scot, I am not. My previous ship was successful so I have high hopes for this one.
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Old 01-03-2021, 01:52 AM
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THE DC THE DC is offline
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Interesting.


Will watch this thread!
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Old 01-03-2021, 07:11 AM
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Damraska Damraska is offline
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Welcome aboard, DC!

...

The asteroid driver now exists as a very simple Blender model.



Along the way I changed the cargo container configuration, mostly to make the ship look more pleasing. This also made room for 8 large solar panels that will deploy from behind the ram.

So far, it looks like a very advanced toilet plunger. :(

Last edited by Damraska; 01-03-2021 at 07:28 AM.
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Old 01-03-2021, 09:49 AM
cfuruti cfuruti is offline
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Quote:
Originally Posted by Damraska View Post
The spun section provides 15,700 square feet of space under artificial gravity, equivalent to about 8 moderately sized homes. I have not done calculations for the rate of spin but estimate this cylinder should provide constant gravity equivalent to one fourth Earth normal, enough to stave off the debilitating effects of prolonged life in micro-gravity.
(sorry, I'm used to international units) If
  • the inner radius of the spinning section is r meters
  • the desired pseudogravity is a m/s˛
  • the section spins at R rotations per minute,
The centripetal acceleration of constant circular motion is a = r omega˛, where omega is the angular velocity in rad/s.
rad/s = 2 pi RPM / 60,
therefore the acceleration at the "bottom" floor is a = r (2 pi RPM / 60)˛ = 4 pi˛ R˛ / 3600
And
  • r = 900 a / (pi˛ R˛)
  • R = (30/pi) sqrt(a/r)
For instance, if you want a = g/4, about 2.5 m/s˛,
  • if R = 5 RPM, r should be about 9.13 m
  • if r is 10 m, R should be about 4.78 RPM
Now you can estimate minimum RPM and radius for acceptable mechanical constraints and practical limits.
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Old 01-03-2021, 10:52 AM
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Wyvern Wyvern is offline
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Most interesting

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Old 01-10-2021, 08:21 PM
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Damraska Damraska is offline
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As usual, I keep rethinking my design. :/



While this may not look much different than the original, it actually contains many improvements and new details.

The ram was redesigned so that, internally, the scoop has enough space to turn the particle flow back upon itself while decelerating it. I also redrew the scoop based on things I learned about Blender, making it easier to convert the blueprints into a three dimensional model.

The cargo containers remain in the same place but the neck became thicker. This means each cargo container now nestles into a rectangular recess, better holding it in place. The neck also gains a great deal of structural strength from the added thickness.

Eight, one hundred foot solar panels will now fold up into the spaces between the cargo containers, giving the asteroid driver electrical generation capacity equivalent to that of the international space station, before adjusting for improvements in solar electric technology. These exist for emergencies and to recharge batteries that can themselves start a tokamak.

The plate at the front of the crew compartment is now armored. If a cargo container breaks free under thrust, it will strike that armor and roll off into space.

The tokamaks were moved forward so they sit directly behind the crew compartment. The tokamak service corridor was moved to sit between the tokamaks. This arrangement makes servicing the engines much easier and the ship looks better, too.

The fuel tanks were moved aft of everything else. In this way, if one breaks free under thrust, it will simply fall away from the ship, not crash into the tokamaks. A ramp at the very end of each fuel tank grab facilitates this and ensures that a break-away fuel tank does not damage the rocket motors.

Four gantries now run the length of the ship. These extend outward exactly as much as the docking collars. These serve two purposes. First, they allow a crew member to space walk outside the ship from the ram to the tokamaks in an enclosed and safe manner. Second, they allow a second asteroid driver to dock such that the entire frame of both vessels is connected. This means any number of asteroid drivers can dock, becoming a single, massive, super driver.

Anyway, I think I have all the major systems worked out now. Tomorrow, I will redraw the core vessel in Blender and unfold it. Then, the really tedious part can begin.

Last edited by Damraska; 01-10-2021 at 08:24 PM. Reason: I be stupids.
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Old 01-10-2021, 11:17 PM
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Quote:
Originally Posted by Damraska View Post
This fuel will spur the creation of a vast array of inter-solar ships, some of which I intend to model.
So, "Stay tuned for further developments" eh.
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