3 ms·

The rings should be modular to ease building and to aid in compartmentalization. However, adding to existing rings could be difficult in terms of planning or en

The rings should be modular to ease building and to aid in compartmentalization. However, adding to existing rings could be difficult in terms of planning or engineering, since you'll be changing the balance of the entire system and you'll probably want the module to be in a particular position. If you instead make the rings "super-modules", you can connect as many as you like along a central axis of rotation. As long as the individual rings are balanced you're good to go. If they spin freely relative to each other, you could even build a super-modular ring in place and only spin it up after it is complete.

hinkley 5y ago
If you plan to add more rings you're going to run into the Dzhanibekov effect https://en.wikipedia.org/wiki/Tennis_racket_theorem https://en.wikipedia.org/wiki/Tennis_racket_theorem, which was still a Soviet state secret at the time space habs were being imagined, and might have still been a secret when they filmed 2010. That station would have been wobbling like crazy. I'm pretty sure that phenomenon even kills the https://en.wikipedia.org/wiki/O%27Neill_cylinder https://en.wikipedia.org/wiki/O%27Neill_cylinder, especially once you introduce liquids and soil to the interior. It's likely that we have to spin the cigar along the long axis to keep from killing everyone, which would greatly reduce the usable surface area and screw up the artificial lighting situation.
- MarkusQ 5y ago
  I think you got that backwards; the long axis of an O'Neill cylinder is the principle axis, and the only one that would be stable. The second (unstable) and third (stable) would both be unsafe because the issue with contents shifting making them potentially switch rolls. But that was never the plan, so no great loss.
  - cgriswald 5y ago
    If I understand correctly, the first principal axis has the smallest moment of inertia and the greatest kinetic energy. Anything that can dissipate the kinetic energy (like soil or water generating heat) will cause the ship to not be able to maintain that rotation and in order to conserve angular momentum it will instead rotate around the other stable axis—the third principal axis or end-over-end—since that axis has the greatest moment of inertia and minimum kinetic energy.

hinkley 5y ago

If you plan to add more rings you're going to run into the Dzhanibekov effect https://en.wikipedia.org/wiki/Tennis_racket_theorem https://en.wikipedia.org/wiki/Tennis_racket_theorem, which was still a Soviet state secret at the time space habs were being imagined, and might have still been a secret when they filmed 2010. That station would have been wobbling like crazy. I'm pretty sure that phenomenon even kills the https://en.wikipedia.org/wiki/O%27Neill_cylinder https://en.wikipedia.org/wiki/O%27Neill_cylinder, especially once you introduce liquids and soil to the interior. It's likely that we have to spin the cigar along the long axis to keep from killing everyone, which would greatly reduce the usable surface area and screw up the artificial lighting situation.

MarkusQ 5y ago
I think you got that backwards; the long axis of an O'Neill cylinder is the principle axis, and the only one that would be stable. The second (unstable) and third (stable) would both be unsafe because the issue with contents shifting making them potentially switch rolls. But that was never the plan, so no great loss.
- cgriswald 5y ago
  If I understand correctly, the first principal axis has the smallest moment of inertia and the greatest kinetic energy. Anything that can dissipate the kinetic energy (like soil or water generating heat) will cause the ship to not be able to maintain that rotation and in order to conserve angular momentum it will instead rotate around the other stable axis—the third principal axis or end-over-end—since that axis has the greatest moment of inertia and minimum kinetic energy.