With liftoff just five days away, ESA's GOCE spacecraft – encased in the protective half-shells of the launcher fairing – has been transported from the cleanroom and installed in the launch tower at the Plesetsk Cosmodrome in northern Russia.

The so-called Upper Composite, which comprises the Gravity field and steady-state Ocean Explorer (GOCE) satellite joined to the Breeze-KM Upper Stage of the Rockot launcher and sealed within the fairing, was protected by a thermal cover and transported by rail from the cleanroom to the launch pad 5 km away. The weather conditions in Plesetsk are very cold at the moment – the ground covered in snow and temperatures well below freezing. However, these conditions do not hamper operations. GOCE has been undergoing preparations for launch since it was taken out of storage around three weeks ago. These launch campaign activities included a series of mechanical and electrical tests, mating to the Upper Stage and finally encapsulation in the launcher fairing.

GOCE is ESA's first Earth Explorer mission and will map global variations in the gravity field with extreme detail and accuracy. This will result in a unique model of the geoid, which is the surface of equal gravitational potential defined by the gravity field. This model of the gravity field is crucial for deriving accurate measurements of ocean circulation and sea-level change, both of which are affected by climate change. GOCE-derived data are also much needed to understand more about processes occurring inside Earth and for use in practical applications such as surveying and levelling.

(Photos... top: The tower supporting the launcher that will carry GOCE into orbit on Monday 16 March 2009. The picture, taken on 11 March, shows the wintery conditions at the launch site. Credits: ESA - S. Corvaja, 2009; center: View of the GOCE satellite in the cleanroom being lowered to join the Upper Stage of the Breeze Rockot launcher prior to encapsulation in the fairing. Credits: ESA - Mohammed Shafiq; bottom: A screen captured from an animation that is based on available gravity measurements and shows the information GOCE will be providing us with. Simplified, it shows how the geoid represents deviations from the Earth's elipsoid. Although it has 'highs'and 'lows'- it is a surface of equal gravitational potential. Therefore, if an object were placed on the surface it would not move. Credits: DLR)