The structure itself, the backbone of Orion, starts at Thales Alenia Space in Turin, Italy. Once they deliver the bare structure to the Airbus integration hall, the tireless work begins installing 20 000 parts, 11 km of cables, 33 engines, and 11 tanks for fuel, water and air.

Many parts for the European Service Module are made-to-measure for Orion and as marvels of engineering, they can take many months to prepare. These so-called long-lead items are ordered years in advance, sometimes before the contracts or even the design reviews have been signed off.