December 2, 2014

Ariane 5 heritage

24 December 1979, the first launcher in the Ariane family roared skyward. The series continued to evolve thereafter, with payload lift capacity to geostationary orbit increasing progressively from 1 tonne on Ariane 1 to 4.8 tonnes for the most powerful variant of Ariane 4. This performance boost was driven by constant technical improvements to the launcher, such as additional solid and liquid boosters and a dual-launch capability on Ariane 3, and a larger payload fairing on Ariane 4.

Ariane 1 to 4: the pioneers

The different variants of Ariane. Credits: CNES/ill.D.Ducros.

At the same time, the programme’s objectives also began to shift their focus. Originally, its aim was to affirm Europe’s independent access to space with a system configured for 2 to 3 launches per year. This policy goal soon morphed into an economic goal when a real space launch market began to emerge in the 1980s.

Imagining a successor to Ariane 4

In 1977, before Ariane 1 had even made its maiden flight and the adoption of the Ariane 2 and Ariane 3 programmes, CNES began working on a heavy-lift launcher to eventually succeed Ariane 4.
This research tied in with work already underway on a human-rated spaceplane called Hermes, which would have required a launcher capable of lofting 15 tonnes into low-Earth orbit with a very high degree of reliability.

The project’s goals were focused on 3 points:

  • Give Europe a competitive launcher to orbit geostationary spacecraft by the late 1990s
  • Give Europe the ability to put humans in space
  • Achieve a dominant position in the low-Earth launch market

On 14 June 1984, an inter-ministerial committee gave CNES the green light to begin preliminary studies for Ariane 5, working with its ESA’s partners.
The programme was approved in January 1985 by Europe’s space ministers in Rome and development got the go-ahead in November 1987 at the ESA Ministerial Council meeting in The Hague.

Developing a launcher for the future

The Ariane 5 programme’s ambition was to make a leap in terms of performance by increasing maximum lift capacity into geostationary transfer orbit (GTO) to 6.8 tonnes—against 4.8 tonnes for Ariane 4—while at the same time significantly reducing launch costs.

Ariane 5 was designed with simplicity and reliability in mind:

  • The two EAP solid booster stages deliver most of the vehicle’s thrust during its ascent through the atmosphere.
  • The EPC main cryogenic stage is powered by a single Vulcain engine.
  • The upper stage is powered by the Aestus engine, originally intended for the Hermes spaceplane.
  • Fully redundant electrical and software systems ensure extra reliability.

Ariane 5 ECA lifts off. Credits: ESA/CNES/Arianespace/CSG Service Optique, 2005.

Ariane 5 was also conceived to adapt to evolving market requirements.
Due to the cost and complexity of the Hermes project, the idea of a hybrid programme was shelved in favour of a launcher rated for unmanned payloads only.

Ariane 5’s first steps

Ariane 5’s first qualification flight on 4 June 1996 ended in failure when the launcher veered off course after 37 seconds and its safety systems triggered an abort. Once the project teams had identified the causes of the failure, they spent nearly 16 months making multiple verifications.

On 30 October 1997, the launcher lifted off from French Guiana on its second flight, which this time was a success despite some anomalies. And on 21 October 1998, the third qualification flight went exactly as planned, clearing the launcher to enter service.