Dutch Space (Leiden, Netherlands) is responsible for the design; development and delivery of the main engine thrust frame of the Ariane 5 launcher. This is a most complex structural sub-system on the Ariane 5 vehicle due to its function as the interface with the Vulcain engine, the lower interface with both boosters and the many interfaces with the Liquid Hydrogen (LH2) and Liquid Oxygen (LOX) fuel lines. Several fairings protect the fuel lines and other systems from the external environment. The fairings also permit the complete sealing of the thrust frame that is flushed with inert gas from the start of fuelling on the launch pad to the point of launch. The current fairings are designed as complex sheet metal fabrications with many different ribs, gussets and skins that are manually assembled and riveted together. This makes the fairings expensive to manufacture and clear candidates for the application of cost cutting technology. Simple calculations suggested that composite fairings would be cheaper. Due to its size, geometry and loading, the LOX line fairing was selected as the most challenging for the design and development of a composite demonstrator fairing.

At the end of 1999, Dutch Space, supported by The Netherlands Agency for Aerospace Programmes (NIVR), set up a research programme in co-operation with Lightweight Structures B.V. and the National Aerospace Laboratory (NLR). 

If you like to read further about this development, please download the loxfairing.pdf paper!