This ‘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.
The Maxwell test chamber — part of ESA’s ESTEC test center in Noordwijk, the Netherlands — performs electromagnetic compatibility testing, ensuring all systems aboard a satellite can operate together without harmful interference.
Maxwell’s metal walls form a ‘Faraday cage,’ screening out all external electromagnetic energy such as TV broadcasts and mobile phone signals.
ESTEC’s dedicated antenna test facilities — comprising the Hertz chamber for full satellites and the smaller Compact Antenna Test Range for antennas — are similarly fitted with metal walls and lined with anechoic foam.