Each satellite also undergoes acoustic testing in the Large European Acoustic Facility, LEAF, effectively the largest sound system in Europe.

A quartet of noise horns are embedded in one wall of this 11 m-wide, 9 m-deep and 16.4 m-high chamber, generating sound by passing nitrogen gas through the horns, surpassing 140 decibels in all. Accelerometers placed within the satellite checked for potentially hazardous internal vibration during this trial by sound.

Once each satellite’s test campaign is over, they are shipped to Europe’s Spaceport in French Guiana and prepared for launch. The two tested spacecraft will leave to Kourou in October, to be launched at the end of the year.