Debris cloud redirection in origami-inspired foldcore structures under hypervelocity impact: a review

The increasing population of micrometeoroids and orbital debris (MMOD) has intensified the need for lightweight and efficient shielding systems capable of withstanding hypervelocity impacts (HVI). Conventional shielding concepts, such as Whipple shields and honeycomb or foam-core sandwich panels, primarily rely on projectile fragmentation and energy absorption but provide limited control over the resulting debris cloud. Origami inspired foldcore structures have recently attracted attention because their open-channel geometry offers the potential to influence fragment trajectories through geometric design. This review summarizes the current state of research on foldcore sandwich structures subjected to HVI, covering both experimental investigations and numerical simulations. The influence of fold geometry, material system, impact location, and loading conditions on debris cloud formation, redirection, and dispersion is discussed and compared with conventional shielding concepts. Based on the available literature, the governing mechanisms of debris-cloud control are identified, and a conceptual Redirection Efficiency Index (REI) together with quantitative descriptors for debris trajectory characterization are proposed to support future performance assessment. The review also discusses current limitations in experimental validation and numerical modelling, and highlights research needs including standardized testing procedures, cumulative damage under repeated impacts, and integrated experimental-computational approaches for the development of future spacecraft shielding systems.