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Enabling & Support

Ariane 5 ECA

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ESA / Enabling & Support / Space Transportation / Launch vehicles
Ariane 5 ECA
Ariane 5 ECA

ESA’s Ariane 5 ECA (Evolved Cryogenic, model A), manufactured by ArianeGroup, has completed over 75 launches from Europe’s Spaceport in French Guiana since 2002. It is 53 m high and 5.4 m diameter with a mass at liftoff of 780 tonnes for a dual satellite launch.

Ariane 5 ECA missions

Ariane 5 ECA is designed to deliver payloads, mainly communications satellites, with a mass of more than 10 t into geostationary transfer orbit (GTO), including the supporting structure and adaptors. The Ariane 5 ECA can launch one, two or three very large satellites. A dual launch configuration is the most commonly used. 

This version of the launcher maintains Europe’s competitiveness in the commercial space transport sector by offering customers the opportunity to launch a wider range of heavier satellites.

Owing to its performance and flexibility to adapt to different missions requirements, Ariane 5 ECA is also used by institutional customers for non-GTO missions. For example, it launched ESA’s Herschel and Plank scientific missions in 2009 to the second Lagrangial point (L2), and Rosetta and BepiColombo to an Earth escape orbit in 2004 and 2018 (respectively). In 2021, Ariane 5 launched the James Webb Space Telescope on its way to L2.

Ariane 5 ECA elements

This launch vehicle configuration consists of three parts.

1. Lower composite (EAP and EPC)

The lower composite comprises:

  • Two boosters (EAP: Etage d’Accélération à Poudre): 3 m diameter, 31 m high, each with 240 t of solid propellant, together providing 1200 t of thrust at liftoff. The maximum thrust during flight can reach 1300 t. EAP burns for about 135 s. After separating from the main stage they reenter the atmosphere above the Atlantic Ocean.
  • The cryogenic main core stage (EPC: Etage Principal Cryotechnique): 5.4 m diameter, 30 m high, containing 175 t of propellants (25 t of liquid hydrogen and 150 t of liquid oxygen), with the Vulcain 2 engine providing 136 t of thrust. EPC operates for about 540 s. It also provides roll control during the main propulsion phase. At shut down, EPC separates from the upper composite at an altitude between 160 km and 210 km, depending on the mission’s trajectory, and performs a destructive reentry in the atmosphere over the Atlantic Ocean.
  • Total liftoff thrust is about 1340 t.

The Vulcain 2 engine is ignited first. A few seconds later, when it reaches its nominal operating level, the two solid-propellant boosters are fired.

Lower composite (EAP and EPC) with Vulcain 2
Lower composite (EAP and EPC) with Vulcain 2

2. Upper composite (ESC-A, VEB and supporting structure)

The upper composite comprises:

  • The cryogenic upper stage (ESC-A: Etage Supérieur Cryotechnique de type A) with 14.7 t of propellant (liquid hydrogen and oxygen). The reliable HM7B engine providing 6.5 t of thrust is reused from Ariane 4’s third stage. It operates for about 945 s and also provides attitude control during the propulsion phase and the separation sequences of the payloads.
  • The Vehicle Equipment Bay (VEB-C), ‘the brain’, autonomously controls the whole vehicle. Its structure is made of composite material. The VEB transmits all key flight parameters to the ground station network.
  • The supporting structure interfacing with the payload. This conical adaptor is mounted on top of the VEB and provides the standard 2624 mm diameter interface with the payload adaptor.
Upper composite (ESC-A, VEB and supporting structure)
Upper composite (ESC-A, VEB and supporting structure)

3. Launcher upper part (fairing and Sylda 5)

The launcher upper part comprises:

  • The fairing protecting the payload at liftoff and during atmospheric flight (5.4 m diameter, 17 m high). The fairing is split by two pyrotechnical commands and jettisoned more than 3 minutes after liftoff, at an altitude above 100 km.
  • The structure accommodating the lower and upper satellites, Sylda 5 (Système de Lancement Double Ariane 5): 4.6 m diameter and height varies from 4.9–6.4 m in increments of   0.3 m. Six versions accommodate the various sizes of satellites.

Ariane 5 ECA typical launch sequence for GTO missions

Typical Ariane 5 ECA launch sequence (GTO mission)
Typical Ariane 5 ECA launch sequence (GTO mission)
Ariane 5 ECA orbital transfer
Ariane 5 ECA orbital transfer

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