Umbilical mast and revalidation

The umbilical mast

The mast is primarily a support for the onboard/ground umbilical connections (ventilation, electrical connections, pressurisation, etc.). Within it we find:

- the systems for pendulum withdrawal (by counterweight) and unlocking of releasable connectors,

- the payload ventilation system, which requires dry, cold air, interfaced with the pneumatic umbilical connectors,

- electrical umbilical connectors,

- the satellite telemetry repeater,

- the cryogenic arms for the launcher’s ECA version, which include fluid and mechanical connections for automatic fuelling of the stage with cryogenic propellants,

- a wind damper system whose function is to reduce the amplitude of the launcher’s movement due to the wind,

- control cameras.

Regarding the mechanical functions, for all the parts that must be separated from the launcher on lift-off, the counterweight systems pull them back along the mast to avoid them impacting the launcher when it tears free from the table.

Revalidation of the table

After each launch, the table has been subjected to vibrations, gas and smoke ejected by the thrusters and the Vulcain engine. It must be reconditioned before it can begin a new campaign. This revalidation phase, which lasts around a week, begins immediately after lift-off with a deluge of water that cleans the entire structure. This has to be done very quickly to avoid any permanent damage to the connections.

After this, each system will be analysed and, if necessary, parts will be repaired or exchanged, in order to obtain an Operational Reference Status (ERO) which confirms that everything is working properly and the table is ready for a new launcher.

From the beginning to the end of the campaign, all the professions and all the manufacturers at the Space Base will have worked, at one time or another, on the launch table. Arianespace is the operator of this facility, but it is always CNES’s Ground Systems Sub-directorate that is responsible for any developments to it. It is involved in all modifications that need to be made to the table, from minor changes to far more significant ones. CNES remains the facility’s design authority and the guarantor of its complete adaptation to the needs expressed by the operator.