Stability landscape of cylindrical shell buckling

What is the critical load required to crush a soda can or a space rocket shell? Surprisingly, there is no good way to estimate it, because of the presence of critical defects virtually impossible to characterize. Here we measure the response of soda cans to lateral poking and identify a generic stability landscape, which fully characterizes the stability of real imperfect shells in the case where one single defect dominates. We show that the landscape of stability is independent of the loading protocol and the poker geometry. Our results suggest that the complex stability of shells reduces to a low dimensional description and that tracking the ridge and the valley of this landscape defines natural coordinates for describing the stability of shells.