thinking about cylinders

the cylinder

radius R — axis to hull gravity at the rim livable rind depth

tile compartment

↕ probe — where the denizen stands

exaggerate the shell in the cross-section (not to scale)

tension hull & shielding

hull material

wall safety

atmosphere pressure regolith shield depth

regolith ρ ≈ 1500 kg/m³ · interior/floor load ≈ 800 kg/m². both spin, so they press outward on the hull.

structural web (offloads the hoop)

topology

count N reach α

load share to web φ cable section cable material

φ feeds the closed-form estimate; the solver below sizes the real weave from the cable section.

floors & foam (the shell structure)

structure

layers (floors) room footprint

wall thickness grading

bracing

annular sector — wrap into the ring + hoop BC (the annular solve)

show deflection (exaggerated) — watch it carry load

does it hold?

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solved web — closed-form only

radiation shielding

areal density is the honest number; the dose figure is order-of-magnitude (GCR, solar-min, secondaries hand-waved).

what the denizen feels — at the probe

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kinematics at a glance

cross-section — the scope of the possible

Sun-line at the axis; gravity points outward. The hull ring is tinted green if it holds / red if it tears. The web (radial spokes or secant chords) is the alternate load path; secants leave a clear core, spokes don't.

the play-slice — floors of the foam, solved

Stacked floors; gravity points down (toward the hull). Walls are coloured by the frame solver's stress (green→red) and the deflection is exaggerated so you can see it carry load. Gold dots = doors within a floor; purple = stairs/ladders between floors.