The optimum shape of a parachute pack where high pack density is required with no packing-induced damage incurred has long been held to be a right circular cylinder. The pack density possible for any other pack shape is typically lower due to the volume in corners that cannot be packed to the same density. The question frequently arises as to what the maximum pack density would be for a given shape, but to date there has not been a good way to predict it. Evaluations conducted in 1961 for the Apollo program were limited to the pack density attained for two nylon parachute types packed in a right circular cylinder at varying levels of pressure. This data is useful in determining the effect of additional pressure on pack density, but does not include other pack shapes or modern, high-tenacity materials. An investigation was conducted to determine the effect of other pack shapes on parachute packing density. The intent of this effort was to generate a predictive tool to determine a density reduction factor based on pack shape, which will be invaluable for future program planning purposes. Testing consisted of packing a common parachute into various shapes to determine the relationship between the geometric properties of the pack shape and the density of the packed parachute, as a function of packing pressure. This paper describes the tests performed and documents the results of this investigation.
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