Analytical and Computational Particulate Load Models in Planetary Surface Spacecraft Cabins

The pressurized volume of spacecraft and vehicle cabins on future planetary surface missions may potentially be susceptible to planetary dust. Expectations are that these volumes will, to some degree, be exposed to dust intrusion via extravehicular activity, leading to elevated particle concentrations that may prove harmful to the crew. To properly design filtration systems for these vehicles, detailed knowledge or data on environmental factors, among them particulate generation loads, will be needed. To address a lack of data in this area, analytical and computation models of particulate generation, transport and removal by filtration in closed cabin environments are being developed. Data from the International Space Station as well as data derived from the Apollo missions were used as inputs to these models. For the computational effort, a Computational Fluid Dynamic solver coupled with a Lagrangian discrete phase (particle) model was used to simulate the planetary dust loads, transport and transients that may take place after an EVA event. The transient simulations showing the dynamics of particle dissipation were particularly interesting for comparing against an analytically derived decay model, and for providing additional insight into the relationship between dissipation rates and particle distribution throughout the volume. This paper reports on the initial results and recommendations derived from the modeling effort.