Moho Artificial Gravity Surface Station: Rototron XVI

[Jamie Logan]

Hey everyone!

This one's so wild, it'll make your head spin!

 

Most of us have tried our hand at building an artificial gravity station, either by building a conventional orbital station with a working centrifuge, or even building an entire spinning 2001-style vessel. Both are wonderful, but what if your Kerbals are going to be spending months on end not in zero gee, but on the surface of a body with a surface gravity less than that of Kerbin, like Moho (g = 2.7 m/s^2)? We can still put a centrifuge to work, but this time it'll be there to provide the additional acceleration that we need in combination with Moho's surface graviy to obtain a 9.81 m/s^2 net acceleration on our Kerbals, ensuring the long term health of their little (presumably) green musculoskeletal systems.

 

To this end, I've developed the Rototron XVI. An artificial gravity surface base with the capability of reaching Moho with a crew of 32 Kerbals. When deployed on the surface, the centrifuge can be run indefinitely due to the combined ISRU refinery and fuel cell array. The station is constructed in LKO via two separate launches; one for the centrifuge and crew cabins, and another for the main engines and landing support structure. The crew of 32 is launched separately, along with an additional fuel tank that will be used to provide the rest of the delta-v we'll need to make the interplanetary transfer to Moho. A region near Moho's south pole was chosen as our landing site due to the abundance of low-altitude flat land, as the axis of rotation of the centrifuge must be as close to parallel to the local gravity field as possible to sustain constant acceleration. 

 

From left to right: R-XVI Centrifuge, R-XVI Crew Module, and R-XVI Landing Support Structure,

 

Here is a link to a gif of it under rotation, KSP forums wont let me post it here

https://i.imgur.com/jEbFkj3.gifv

 

The math on this is not terribly difficult. Typically, when constructing an artificial gravity station with the intention of simulating actual 1 gee acceleration, you work out the necessary rate of rotation via:

angular velocity = sqrt ( 9.81 / r )

 

Where "r" is the perpendicular distance between the crew cabin and the axis of rotation. In our case, if we model the two crew cabins as point masses on the ends of massless rods under rotation in a uniform gravitational field, the acceleration experienced by the crew cabins can be evaluated merely as a function of the angle of splay of the crew cabins while under rotation (such as with a centrifugal governor). Thus, we need only calculate the angle of splay that will result from our desired total acceleration:

Splay angle = arcsin( 2.7 / 9.81) = ~16 deg

 

Knowing this, we simply vary the rpm on the main rotor while monitoring the angle display on one of the hinges until the splay angle settles in around 16 deg.

 

 

 

 

Now, we see the launch, construction, landing, and operation:

 

Again, here's another gif: https://i.imgur.com/MPMPMY2.gifv

 

 

I hope you enjoyed this, I sure enjoyed building and flying it. I don't have plans to post the craft files yet, but I will if it seems like there's enough interest.

If you like crazy big spacecraft, you'll also like my last post:

 

[Zephram Kerman]

Ah, good, it only took me 3 years to find this. Great ideas! I've been working on a different augmented gravity surface base concept, but keep getting distracted. Seeing yours completed is both encouraging and inspiring. I like how you did the hinges:  triangles make anything more stable. The final assembly reminds me of a certain carnival ride I can't recall the name of.

In my research and designs so far, I learned the human body requires a certain amount of gravity to avoid many various debilitating medical issues. Thanks to recently increased interest in bases on the Moon and Mars, I'm surprised so few people are considering how to accomplish this.