Space colonies of the future as imagined by NASA in the 1970s

Re:Space colonies of the future as imagined by NASA in the 1... by hinkley on Tuesday November 23, 2021 @12:21PM (#29320433)

If you plan to add more rings you're going to run into the Dzhanibekov effect 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, 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.

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Re:Space colonies of the future as imagined by NASA in the 1... by MarkusQ on Wednesday November 24, 2021 @12:20AM (#29327138)

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.

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Re:Space colonies of the future as imagined by NASA in the 1... by cgriswald on Thursday November 25, 2021 @03:51PM (#29344870)

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.

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