Testing of the ATV's videometer automatic docking system took place at the French defence agency "Délégation Générale pour l'Armement" (DGA), located in Val-de-Reuil. Inside an exceptional building, 600 metres in length, a 120 000 kg mobile platform, able to ride on 550 metre long rails, enabled the simulation of a continuous approach between the two space vehicles from a range of several hundred metres to within almost docking distance.