- European
Space Agency satellite GOCE
successfully launched into space from Plesetsk
- Astrium
satellite platform enables highly accurate flight path
- Gravitation
mission focuses on ocean currents and magma flow
The European research satellite will investigate the seas, oceans and interior
of the Earth from an altitude of about 250 kilometres for at least 24 months.
GOCE was implemented by an international industrial consortium led by Thales
Alenia Space on behalf of the European Space Agency (ESA). As a core team
member Astrium in Friedrichshafen
contributed significantly to the project by building the satellite platform.
Astrium Spain
has delivered the carbon-fibre structure for the platform.
The
measurement data delivered by the satellite will enable the Earth’s
gravitational field to be measured more accurately than ever before. The
information will make it possible not only to study the structure of the Earth’s
interior in greater detail, but also to measure the potential rise in the level
of the ocean and to analyse ocean currents that are of decisive importance to
our climate. In this way, GOCE will help to improve current climate models and
forecasts.
Satellites
offer the only possible way to survey the entire gravitational force field of
the Earth uniformly. To be capable of carrying out such gravitational
measurements as perfectly as possible, the GOCE satellite was designed in such
a way that it can fly in a particularly low orbit above the Earth’s surface.
This is where the satellite platform, for which Astrium is responsible, plays a
special role: The instruments and the satellite body together form a whole, and
there are no movable, mechanical parts anywhere inside the satellite. This
means it can travel steadily and smoothly along its trajectory without any
interfering acceleration caused by tiny movements inside it, which could
falsify the measurements taken. Aerodynamic deviations due to the residual atmosphere
will also be minimized, and any orbital deviations not caused by gravitational
differences will be offset by electric ion thrusters triggered by an active,
continuous, high-precision attitude (drag-free) and orbit control system.
GOCE ‘surfs’ in the gravitational field
The Earth’s
gravitational field is not entirely symmetrical. Rather like the surface of the
ocean, it has numerous ‘bumps’ or ‘dents’ (referred to by experts as
‘anomalies’). These put GOCE on a slightly wavy trajectory, much like a surfer
in the sea. In the region of stronger gravitational force, GOCE will slightly
lose height and speed up, whereas in regions of weaker gravitational force it
will climb to a higher orbit and slow down.
From this trajectory, it will be possible to derive a global ‘map’ of the
Earth’s gravitational field (a geoid) with exceptional accuracy and resolution.
Astrium, a
wholly owned subsidiary of EADS, is dedicated to providing civil and defence
space systems and services. In 2008, Astrium had a turnover of €4.3 billion and
13,000 employees in France, Germany, the United
Kingdom, Spain
and the Netherlands.
Its three main areas of activity are Astrium Space Transportation for launchers
and orbital infrastructure, Astrium Satellites for spacecraft and ground
segment and Astrium Services for the development and delivery of satellite services.
EADS
is a global leader in aerospace, defence and related services. In 2008,
EADS generated revenues of €43.3 billion and employed a workforce of more
than 118, 000.
Media Contacts:
Matthieu Duvelleroy
(Astrium FR) Phone:
+33 (0) 1 77 75 80 32
Jeremy Close
(Astrium UK) Phone:
+44 (0)1 438 77 3872
Mathias Pikelj (Astrium GER) Phone: +49 (0)
7545 8 9123
Francisco
Lechón (Astrium SP) Phone:
+34 (0) 91 586 37 41
www.astrium.eads.net
