ESA structures engineer Simon Whent, supporting the design of the Hera spacecraft structure and many of its payloads, comments: “Even though this acoustic testing has been exhaustively modelled ahead of time, it was still a nerve-wracking moment as the giant doors of the LEAF chamber close and then the horns are activated. Each test session lasts for just a minute – but that still seemed like a very long time as we waited to find out if Hera’s structure and components withstand the sound waves blasting it.”

ESA mechanical systems and structures engineer Cliff Ashcroft, who led the design of Hera’s central tube ‘backbone’, adds: “In reality, the highest, most damaging levels of acoustic pressure are felt during the early launch phase, generated at or close to lift-off, when the vibrations reflected from the pad and local facility, bombard the departing launcher. It is a kind of final acoustic ‘pat on the back’ as the launcher and spacecraft depart from Earth.”