The air present in every spacecraft will vent during launch, so spacecraft hardware must be designed sufficiently to withstand the resulting pressure differences that develop as the external pressure decreases from that at sea level to negligible levels in about 2 minutes. Pressure differentials can be significant, especially for honeycomb panels within which air must travel through many small perforations in honeycomb cell walls to reach vent ports, and cases have been reported of honeycomb panels exploding during launch. Thus, work has been conducted at Ball Aerospace to not only model air venting from honeycomb panels, but also develop techniques to simplify the simulations. Predictions have compared well with pressure differences measured in a test panel during depressurization tests. The results provide confidence in the ability to predict pressure differences in honeycomb panels of any shape and cell size.
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