Bâtiment Assembleur Lanceur at Europe's Spaceport

The Bâtiment Assembleur Lanceur (BIL) at Europe's Spaceport in French Guiana, 2022.

The launcher assembly building (known as BIL from the French abbreviation “Batiment Assembleur Lanceur”) was used for assembly of Europe’s now-retired Ariane 5 rocket at Europe’s Spaceport in French Guiana. The assembly building was officially transferred to Avio on 2 December 2025. 

Avio will refurbish the building to assemble its Vega-C and future Vega-E launchers, allowing more Vega rockets to be launched a year. The building will be rebranded as the Vega Assembly Building (VAB).

ESA and Arianespace officially handed over the keys as part of decisions taken at the 2023 Space Summit in Seville, where Member States recognised the need to strengthen Europe’s launch possibilities, optimise existing infrastructure, and increase the launch cadence.

The launcher integration building is a 127-m long steel structure, 31 meters wide and 58-m high to allow for Ariane 5 assembly. Part of the Ariane 5 launch zone – Ensemble de Lancement Ariane-3 – the building supported all the Ariane 5 launches from first liftoff in 1996 to the last launch in 2023.

The elements for Ariane 5 were assembled vertically at the launcher assembly building starting with the main stage followed by its two boosters and then the upper stage. Once complete Ariane 5 rolled on a railway to the final assembly building where the upper part including payload was added. Ariane 6 is assembled horizontally in its own building near the Ariane 6 launch pad.