The teams at Europe’s Spaceport in Kourou, French Guiana, have carried out all the mechanical connections in order to join the launcher’s central core – comprising the main stage and the upper stage – to its two Equipped Solid Rockets, or boosters.

These operations were carried out in two phases, the first to position the central core on the boosters and the second to undertake the mechanical connections at the top and bottom of the boosters.

The central core, suspended from the mobile gantry crane, was lowered and positioned on the boosters by means of pre-installed guides to ensure positioning to within a few hundredths of a millimeter.

The teams then completed installation of a mechanism to control the lateral movement of the boosters at the anchor point between its rear skirt and the main stage engine frame. This was followed by the installation of four link rods, two per booster.

Mechanical assembly of the launcher (without its upper part) finished with the assembly of the UPPA (Equipped Upper Attachment Bolt System) bolts used for transmission of the booster thrust force to the rest of the launcher and for separating the boosters. All this equipment provides the mechanical connection between the boosters and the central core during the entire booster flight phase, before separation at H0+135 seconds.