TIM FURNISS / LONDON
First stage engine will be redesigned following nozzle failure on launcher's maiden mission
A dedicated qualification flight of the Ariane 5 ECA launch vehicle has been scheduled for March 2004. This will follow a redesign of the Vulcain 2 first-stage engine after the failure of the nozzle on the maiden flight of the uprated Ariane 5 in December 2002, resulting in the loss of two communications satellites.
Until the improved launch vehicle, with uprated ESC-A upper stage, is requalified, commercial missions will use the basic Ariane 5G, which has flown 15 times with two total failures and two partial failures where the system did not place payloads into their correct orbits. The Ariane 5G is the only vehicle in Arianespace's inventory since the launch of the last Ariane 4 in 2002.
The Ariane 5 ECA is expected to be approved for commercial operations after a second flight of the Vulcain 2 on the first newly designated Ariane 5ES model. The ES is an Ariane 5G with Vulcain 2 first-stage engine and restartable EPS upper stage. The European Space Agency-funded flight is due in September 2004, carrying ESA's first Automated Transfer Vehicle cargo carrier for the International Space Station.
The timing of the first ECA commercial mission will depend on the demonstration and ES flights. A new batch of Ariane 5G and ECA vehicles will be ordered next month to cover launches from 2005. The additional 5Gs will ensure Arianespace does not have to rely on a sole booster for commercial services.
Had the first ECA launch been successful, no further Ariane 5Gs would have been ordered. The failure has exposed the risk in Arianespace's plan to rely on a single booster type after development of an ECA-B was earlier cancelled.
Source: Flight International
