Living Planet   


Development status of the GOCE programme

Dr Rune Floberghagen(1), Franz-Josef Demond(1) , Pier Paolo Emanuelli(2) , Danilo Muzi(1) , and Dr Alex Popescu(1)

(1) ESA-ESTEC, Keplerlaan 1, 2200 AG Noordwijk, Netherlands
(2) ESA-ESOC, Robert-Bosch-Strasse 5, 64293 Darmstadt, Germany


Scheduled for launch in 2006, the Gravity Field and Steady State Ocean Circulation Explorer (GOCE) mission is the first of the Earth Explorer Core Missions planned as part of ESA's Earth Observation Envelope Programme.

The goal of the GOCE mission is to provide high-resolution and high-accuracy global models of the Earth's gravity field and derived quantities, such as the geoid, geoid slopes and gravity anomalies, along with their associated error measures. Such an advance in the knowledge of the Earth's gravity field will help to develop a deeper understanding of the physics of the Earth's interior, the interaction of the continents and the ocean circulation.

To achieve its objectives, the GOCE mission is designed to meet the following key requirements:

- uninterrupted tracking of the satellite in three spatial dimensions

- measurement and compensation of the effect of the non-gravitational forces

- orbital altitude as low as possible

enhancing the strength of the high frequency components of the gravity field signal by differentiation (counteraction of attenuation with altitude)

These key requirements drive the design of the satellite, the choice of the orbit in all mission phases as well as the selection of the core payload.

The primary payload consists of a highly sophisticated three-axis electrostatic gradiometer and a geodetic-quality GPS receiver. In order to minimise atmospheric drag, the satellite has an elongated shape with a minimal cross-sectional area in the flight direction. A combined "drag-free'' and attitude control system ensures the minimisation of residual non-conservative forces and torques acting on the spacecraft. The satellite is also aerodynamically stabilised by using small winglets to control the position of the centre-of-pressure with respect to the centre-of-mass. During gravity mapping the orbit altitude will be 250 km or lower, but still compatible with operational requirements.

The paper addresses key aspects of the GOCE mission and their development status, including:

- the programmatic status,

- the space segment, including the performance of the satellite data,

- the ground segment, including satellite operations and data processing


Workshop presentation

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry