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International audience; Spacecrafts such as Stardust (NASA, 2006) are protected by an ablative Thermal Protection System (TPS) for their hypersonic atmospheric entry. A new generation of TPS material, called Phenolic Impregnated Carbon Ablator (PICA), has been introduced with the Stardust mission. This new generation of low density carbon-phenolic composites is now widely used in the aerospace industry. Complex heat and mass transfer phenomena coupled to phenolic pyrolysis and pyrolysis gas chemistry occur in the material during atmospheric entry. Computer programs, as the Porous material Analysis Toolbox based on OpenFoam (PATO) released open source by NASA, allow to study the material response. In this study, a non-intrusive Anchored Analysis of Variance (Anchored-ANOVA) method has been interfaced with PATO to perform low-cost sensitivity analysis on this problem featuring a large number of uncertain parameters. Then, a Polynomial-Chaos method has been employed in order to compute the statistics of some quantities of interest for the atmospheric entry of the Stardust capsule, by taking into account uncertainties on effective material properties and pyrolysis gas composition. This first study including pyrolysis gas composition uncertainties shows their key contribution to the variability of the quantities of interest.

Slippery, liquid-infused porous surfaces offer a promising route for producing omniphobic and anti-icing surfaces. Typically, these surfaces are made as a coating with expensive and time consuming assembly methods or with fluorinated films and oils. We report on a route for producing liquid-infused surfaces, which utilizes a liquid precursor fed oxygen-hydrogen flame to produce titania nanoparticles deposited directly on a low-density polyethylene film. This porous nanocoating, with thickness of several hundreds of nanometers, is then filled with silicone oil. The produced surfaces are shown to exhibit excellent anti-icing properties, with an ice adhesion strength of ∼12 kPa, which is an order of magnitude improvement when compared to the plain polyethylene film. The surface was also capable of maintaining this property even after cyclic icing testing. Slippery, liquid-infused porous surfaces (SLIPSs) are nature inspired surfaces that are designed to repel liquid and solid materials. These surfaces have been shown to pose anti-icing properties, which broadens the available end-uses from the chemical industry to arctic transportation and energy production. The method behind repellency of SLIPSs relies on preventing outside liquids from penetrating the surface structure to the Wenzel state. Instead, the slippery liquid within the porous solid supports the Cassie-Baxter state (instead of air, here the porous structure is filled with lubricant), where the reduced area of the porous solid surface is available to interact with the liquid or ice to be repelled. The difference between Wenzel and Cassie-Baxter states is illustrated in Figure 1. This phenomenon is exploited in many superhydrophobic surfaces where an air cushion is entrapped within the porous solid surface. As a result, spherical water drops easily roll off the surface (and have static contact angles larger than 150°). publishedVersion