The requirements of commercial satellite operators and other space payload
customers are growing steadily. Communication satellites, for example, do
not only increase in efficiency but also in size and weight. However,
maintaining the position as the world’s leading supplier of launcher systems
in the long run requires continuous evolution of the European launcher
system Ariane 5. Within the Ariane 5 Plus programme, the Space
Infrastructure business division of Astrium will be responsible for all
development activities in connection with the Ariane 5 upper stage and is
thus the sole manufacturer of upper stages for all the Ariane versions.
Even today, Ariane 5 is considered the world’s most powerful launcher for
the transport of payloads to low-earth and geostationary orbits. After
completion of the development phase, however, it turned out that the
original design specification, a maximum payload capacity of six tons for
transports to geostationary transfer orbits, would be insufficient for many
future applications. Evolution of the Ariane 5 aims at gradually and
continually improving payload capacity and range of applications of the
launcher in order to be able to offer potential customers best launch
service on accommodating terms. The Ariane 5 Plus programme consists of
three major steps:

  • Development of a new Ariane 5 upper stage (ESC-A) using an already existing
    cryogenic engine from Ariane 4,
  • Development of the new cryogenic upper stage engine VINCI and adaptation to
    the upper stage ESC-A (ESC-B),
  • Modification of the current Ariane 5 upper stage including the Aestus engine
    to allow versatile missions profiles (EPS-Versatile),
  • Development of a new control unit.
  • Cryogenic engine for the upper stage

Main part of the latest Ariane 5 adaptation-to-market programme (Ariane 5
Plus) is the development of the new upper stage ESC-A (Etage SupÈrieur
Cryotechnique A). The upper stage, which works on a cryogenic basis using
supercooled, high-energy propellants (liquid hydrogen/liquid oxygen), will
increase payload capacity by two tons. The propulsion system of the third
stage of Ariane 4 including the cryogenic HM-7 engine will be integrated
into the Ariane 5 upper stage using the existing oxygen tank and thrust
structure complemented by a new hydrogen tank. Propellant mass of the upper
stage engine will increase from eleven tons (standard version) to 14 tons.
Using tried and tested components will cut production cost distinctly and
reduce development time to three years.

At the same time, thrust of the main stage engine of Ariane 5 will be
improved and propellant mass of the main stage be increased from 155 to 172
within the Ariane 5 E programme. After jettisoning of the solid-propellant
boosters, the Vulcain main-stage engine will be the launcher’s sole
propulsion for a flight phase of eight minutes. Power of the Vulcain-2
engine will increase by about 30% to 135 tons as compared with the
predecessor version. This increase in power was generated by modifying
thrust chamber and turbo pump. Thanks to the new Ariane 5 upper stage ESC-A
and the measures to be taken to improve the thrust of boosters and main
stage, payload capacity of Ariane 5 will thus increase from about six to up
to ten tons. First launch of Ariane 5ECA is scheduled for the middle of
2002.

Modified Aestus engine to allow up to five re-ignitions

At the same time, power of the upper stage EPS (Etage Propergols Stockables)
of the current Ariane 5 version will also be increased. Modification of the
propulsion system is intended to allow five re-ignitions of the EPS during a
free-flight phase of up to six hours and delivery of satellites to different
orbits. Thus, Ariane 5 will be able to meet the requirements of or than 90%
of all satellite operators and can be used as a versatile means for “space
transport”. The so-called Ariane 5 Versatile is scheduled for first launch
at the end of 2002.

Intelligent control unit the “brain” of Ariane

In the Ariane 5 programme, Astrium is responsible for the so-called “Vehicle
Equipment Bay” (VEB), a control unit, the onboard computers of which will
electronically control engine ignition, stage separation and flight control
of Ariane 5. As to the Ariane 5 Plus programme, Astrium recently started
testing of the three new VEB versions in Toulouse. These versions had been
adapted to the new Ariane mission profiles and can thus be used for Ariane 5
“Versatile” and the new cryogenic upper stages.

ESA decision to be expected for November 2001

Intended goal in programme evolution is the development of the upper stage
ESC-B, which will be ready for operation by 2006. This upper stage comprises
the completely new, re-ignitable VINCI cryogenic engine, with the help of
which payload capacity will rise to 12 tons. It will thus meet all
foreseeable market requirements and ensure the competitiveness of Ariane 5.
A decision on the appropriation of the funds required for ESC-B development
is expected to be taken on the occasion of this year’s meeting of the
council of ESA ministers to be held in Edinburgh under the presidency of the
German Federal Minister of Education and Research, Edelgard Bulmahn.
Astrium is a joint company of EADS European Aeronautic Defence and Space
Company and BAE Systems.

Paris/Le Bourget, June 2001

Your contact: Astrium Space Infrastructure

Mrs. Kirsten Leung

Phone: tel: +49-421-539-5326

fax: +49-421-539-4534