![](\"http:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2014\/06\/atv_shielding_after_impact_test\/14591456-1-eng-GB\/ATV_shielding_after_impact_test_small.jpg\")
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\nAn exit hole through Kevlar\u2013Nextel fabric after hypervelocity testing of the multilayer shielding for ESA\u2019s ATV space freighter, simulating an impact by space debris. The good news is that testing confirms the spacecraft’s pressure shell would survive such a collision intact.\n<\/p>\n
\nTesting was carried out for ESA\u2019s Space Environment and Effects section at the Fraunhofer<\/a> Institute for High-Speed Dynamics, Ernst-Mach-Institut, EMI,<\/a> <\/u>in Freiburg, Germany, using a high-performance light-gas gun.\n<\/p>\n \nA 7.5 mm-diameter aluminium bullet was shot at 7 km\/s towards the same \u2018stuffed Whipple shield\u2019 design used to protect the ATV and the other International Space Station manned modules.\n<\/p>\n \nThis represents the upper end of the size of debris the shield is designed to cope with. Multiple layers give greater protection than a single thick aluminium layer.\n<\/p>\n \nThe debris begins by piercing a blanket of multilayer insulation, followed by a 1 mm-thick aluminium \u2018bumper shield\u2019<\/a>.\n<\/p>\n \nThis impact makes the solid object break apart into a cloud of fragments and vapour, which becomes easier for the following layers to capture or deflect. Next comes the layer of stuffing seen in this main photo, a weave of lightweight Kevlar and Nextel fabric, which further slows the incoming debris.\n<\/p>\n \nThe stuffing fabric and a surrounding sheet has been thoroughly shredded by the impact, but the overall mass and energy of the debris has been sufficiently dissipated that it has merely harmlessly scorched the innermost 3-mm-thick aluminium wall<\/a>.\n<\/p>\n \nIn orbit, this entire shield measures just 128 mm across.\n<\/p>\n \nThe stronger-than-steel Kevlar fabric was invented by Stephanie Kwolek of the DuPont company, who died this month.\n<\/p>\n \nOn Earth, her invention\u2019s \u2018killer app\u2019 proved to be bulletproof vests; its use on the Space Station helps to ensure that module hulls could be designed several centimetres thinner than would otherwise be the case.\n<\/p>\n \nESA\u2019s next and final ATV, Georges Lema\u00eetre<\/i><\/a>, will be launched to the orbital outpost this summer.<\/p>\n","protected":false},"excerpt":{"rendered":" \t\t\t\t\t \nAn exit hole through Kevlar\u2013Nextel fabric after hypervelocity testing of the multilayer shielding for ESA\u2019s ATV space freighter, simulating an impact by space debris. The good news is that testing confirms the spacecraft’s pressure shell would survive such a collision intact.\n<\/p>\n \nTesting was carried out for ESA\u2019s Space Environment and Effects section at the Fraunhofer<\/a> Institute for High-Speed Dynamics, Ernst-Mach-Institut, EMI,<\/a> <\/u>in Freiburg, Germany, using a high-performance light-gas gun.\n<\/p>\n \nA 7.5 mm-diameter aluminium bullet was shot at 7 km\/s towards the same \u2018stuffed Whipple shield\u2019 design used to protect the ATV and the other International Space Station manned modules.\n<\/p>\n \nThis represents the upper end of the size of debris the shield is designed to cope with. Multiple layers give greater protection than a single thick aluminium layer.\n<\/p>\n \nThe debris begins by piercing a blanket of multilayer insulation, followed by a 1 mm-thick aluminium \u2018bumper shield\u2019<\/a>.\n<\/p>\n \nThis impact makes the solid object break apart into a cloud of fragments and vapour, which becomes easier for the following layers to capture or deflect. Next comes the layer of stuffing seen in this main photo, a weave of lightweight Kevlar and Nextel fabric, which further slows the incoming debris.\n<\/p>\n \nThe stuffing fabric and a surrounding sheet has been thoroughly shredded by the impact, but the overall mass and energy of the debris has been sufficiently dissipated that it has merely harmlessly scorched the innermost 3-mm-thick aluminium wall<\/a>.\n<\/p>\n \nIn orbit, this entire shield measures just 128 mm across.\n<\/p>\n \nThe stronger-than-steel Kevlar fabric was invented by Stephanie Kwolek of the DuPont company, who died this month.\n<\/p>\n \nOn Earth, her invention\u2019s \u2018killer app\u2019 proved to be bulletproof vests; its use on the Space Station helps to ensure that module hulls could be designed several centimetres thinner than would otherwise be the case.\n<\/p>\n<\/p>\n