Ariane 5 evolutions
Between 1996 and 2003 the Ariane 5 Generic launcher made 16 launches from Europe's Spaceport. Depending on the payload, the configuration of the upper part of the launcher was adapted for each launch to ensure the optimum accommodation of single, dual or, for Flight 162 on 27 September 2003, a triple payload.
Apart from the initial qualification flight which ended in failure 39 seconds after liftoff, and the 10th flight where a problem with the storable propellant stage (EPS) placed one satellite in an unrecoverable orbit, the Ariane 5 Generic launcher has demonstrated its robustness and reliability.
Ariane 5 Generic Plus (A5G+)
To improve the performance of the initial Ariane 5 version and to respond to evolution in market demand, a set of small but important changes were introduced on a limited number of launchers. Launchers with these modifications were referred to as the Ariane 5 Generic Plus.
These changes comprised:
- introduction of the lighter P2001 nozzle on the EAP boosters
- modifications to the EPS upper stage: increased capacity of the two MMH tanks (+ 300 kg of ergols); modified mixture ratio of the Aestus engine
- modifications to the vehicle equipment bay (VEB): replacing the aluminium structure with a lighter composite version; a new separation system for the VEB and the main stage to reduce the shock created during separation; new electrical equipment and components
All these modifications led to an increase in performance for a standard geostationary transfer orbit of 150 kg net payload.
The Ariane 5G+ operated flawlessly on the three launches made in 2004.
Ariane 5 Evolution
In the mid 1990s an analysis of the launch market was carried out. This showed that the majority of customers require launches into geosynchronous transfer orbit and identified the need for further upgrades of the Ariane launch capacity.
Decisions to modify and improve Ariane 5 launcher versions were taken leading to the development of the:
- Ariane 5 ECA
- Ariane 5 GS
- Ariane 5 ES