Development status of the VESCO engine for Ariane 5 upper stage

Abstract

The VESCO engine is a new generation cryogenic upper stage engine which will power the Ariane 5 launcher from 2005 2006 onwards. Based on market analysis, the decision has been taken in June 1998 to start the development of a new cryogenic upper stage for Ariane 5. This development targets to offer at this date of 2005 2006 a dual launch GTO payload capacity above 11 metric tons, in order to face the growth of spacecrafts weight, -while keeping the general Ariane strategy of dual launch. The requested increase of performance is gained thanks to the very significant Isp growth from the storable propulsion, which is the current technology of Ariane 5 upper stage, to the cryogenic. A rather high level of thrust is also mandatory for the engine, in order to optimize the launcher performance. Even of main importance, the GTO market is not the only one ‘to be considered. New strategies, such as GTO+ or super-(GTO, will probably be requested in the future to set spacecratfs on final geostationary orbit. Such missions bring the advantage of reducing the AV to provide by the spacecraft. As far as the launcher is concerned, their main drawback is the need for multiple ignitions of the upper stage, after coarse phases. This reignition capacity, together with the high levels of reliability, thrust and Isp is obviously one of the -major requirements for the VESCO engine. Copyright