ESA Science & Technology - Herschel mated with Ariane 5 ECA Launcher

Move to the final assembly building

On Wednesday 29 April the Herschel spacecraft was transported from the S5B building to the final assembly building (Bâtiment d'Assemblage Final, or BAF) at the Ariane launch site of the European spaceport in Kourou. For this transport, over about 10 kilometres, the Herschel spacecraft was placed inside the payload transport container (Conteneur Charge Utile 3, or CCU3) at the S5B building.

The CCU3 transport container was used to maintain a cleanroom environment during the transport to the BAF. Upon arrival at the BAF, the CCU3 container was placed inside the BAF airlock. This 47-m-high part of the BAF building at its top has an opening into the adjacent 90-m-high hall where the Ariane 5 ECA launcher stands.

Herschel  mating with launcher

After ensuring cleanroom conditions inside the BAF airlock, on the next morning the spacecraft was rolled out of the CCU3 container. The launcher ring adapter, which was already installed at the base of the spacecraft's service module, was disconnected from the raising cylinder on the CCU3 pallet.

Rolling the spacecraft out of the CCU3 container (left), disconnecting from the raising cylinder on the CCU3 pallet (middle) and lifting of the spacecraft with the vertical lifting device (right). Credit: ESA-CNES-Arianespace / Optique Vidéo du CSG - JM Guillon

With the spacecraft secured by the three arms of the vertical lifting device, Herschel was lifted from the CCU3 pallet and hoisted up inside the BAF airlock and into to the high bay of the BAF.

The Herschel spacecraft is hoisted up through the shaft connecting the BAF airlock and the adjacent high hall. Left: upward view from inside the airlock; right: downward view from a platform in the high hall. Credit: ESA-CNES-Arianespace / Optique Vidéo du CSG - JM Guillon

Inside the high bay stood the Ariane 5 ECA launcher with the Planck spacecraft and the SYLDA 5 support structure, which were mated already on top of the launcher on 23 and 27 April, respectively.

The SYLDA 5 (Système de Lancement Double Ariane 5) is a support structure that can be used during joint launches on an Ariane 5 launcher to carry the upper part of the launcher's payload, which in this case is the Herschel spacecraft. It consists of a load-bearing carbon structure that at its base is fixed to the launcher. With its high cylindrical shell and truncated conical shell at the top the SYLDA 5 encapsulates the lower part of the launcher's payload; in this case the Planck spacecraft.

The top of the SYLDA 5 is open through which the top 25 centimetres of the Planck spacecraft protrude. This part of the Planck spacecraft will be enclosed in the space just under the Herschel spacecraft, inside the about 0.33-m-high launcher adapter ring (ACU).

Looking up at the Herschel spacecraft as it is manoeuvred in place over the SYLDA 5. Credit: ESA-CNES-Arianespace / Optique Vidéo du CSG - JM Guillon	The Herschel spacecraft is lowered into place on top of the SYLDA 5, with the top of the Planck telescope just visible inside it. Credit: ESA

	Left: Personnel on the access platform guide the Herschel spacecraft during the final few centimetres. Above: The base of the launcher adapter ring is bolted to the top of the SYLDA 5. Credit: ESA-CNES-Arianespace / Optique Vidéo du CSG - JM Guillon

The launcher carrying the two spacecraft (which is over 35 metres tall) is hidden from view by the two movable access platforms that surround the top of the launcher at the level just below the base of the SYLDA 5 and at the top of the SYLDA 5 or as convenient.