Life-Support Pressure Vessel Material Selector — 2D Cross-Section

Spacecraft life-support systems store oxygen, nitrogen and water in pressurized tanks whose structural material is picked from a small shortlist — titanium alloy, aluminum alloy, stainless steel, nickel superalloy or carbon-fibre composite — each with a different strength, density and fatigue behaviour. This 2D companion draws a live cutaway of the tank's cylindrical cross-section: the same thin-wall hoop-stress design equation sizes the wall thickness for a chosen material, pressure, radius and safety factor, then computes the resulting mass and an estimated fatigue-cycle life from the material's Basquin fatigue constants, with the wall (exaggerated for visibility) and drifting pressurized-gas dots redrawing on every slider change.