![](\"http:\/\/www.esa.int\/var\/esa\/storage\/images\/esa_multimedia\/images\/2014\/03\/anechoic_foam_covering\/14348522-1-eng-GB\/Anechoic_foam_covering_small.jpg\")
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\nThese spiky foam wedges, seen here in ESA\u2019s Maxwell test chamber, cover the walls of facilities that simulate the endless void of space.\n<\/p>\n
\nThis \u2018anechoic\u2019 foam absorbs radio signals, enabling radio-frequency testing without any distorting reflections from the chamber walls. In addition, it also absorbs sound \u2013 making these chambers eerily quiet places to work.\n<\/p>\n
\nThe Maxwell test chamber \u2013 part of ESA\u2019s ESTEC test centre<\/a> in Noordwijk, the Netherlands \u2013 performs electromagnetic compatibility testing, ensuring all systems aboard a satellite can operate together without harmful interference.\n<\/p>\n \nMaxwell\u2019s metal walls form a \u2018Faraday cage\u2019, screening out all external electromagnetic energy such as TV broadcasts and mobile phone signals.\n<\/p>\n \nESTEC\u2019s dedicated antenna test facilities<\/a> \u2013 comprising the Hertz chamber for full satellites and the smaller Compact Antenna Test Range for antennas \u2013 are similarly fitted with metal walls and lined with anechoic foam.<\/p>\n","protected":false},"excerpt":{"rendered":" \nThese spiky foam wedges, seen here in ESA’s Maxwell test chamber, cover the walls of facilities that simulate the endless void of space.\n<\/p>\n \nThis ‘anechoic’ foam absorbs radio signals, enabling radio-frequency testing without any distorting reflections from the chamber walls. In addition, it also absorbs sound – making these chambers eerily quiet places to work.\n<\/p>\n \nThe Maxwell test chamber – part of ESA’s ESTEC test centre<\/a> in Noordwijk, the Netherlands – performs electromagnetic compatibility testing, ensuring all systems aboard a satellite can operate together without harmful interference.\n<\/p>\n \nMaxwell’s metal walls form a ‘Faraday cage’, screening out all external electromagnetic energy such as TV broadcasts and mobile phone signals.\n<\/p>\n<\/p>\n