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GOCE (the Gravity Field and Steady State Ocean Circulation Explorer) is the first Earth Explorer Core Mission of the Earth Observation Envelope Program of the European Space Agency (ESA). The Satellite is planned to be launched in June 2008 on a Rockot launcher into a near-circular sun-synchronous orbit for Earth's gravity field measurements. The objective of the mission is to produce high-accuracy, high-resolution, global measurements of the Earth's gravity by satellite, leading to improved gravity field and geoid models for use in a wide range of applications (geodesy, solid-Earth physics, oceanography, climate, ice topography). In particular, the goal is to produce a map of the gravity anomaly field with an accuracy better than 1mGal (1 mGal=10-5 m s-2), and of the geoid height with accuracy better than 1 cm, all over the Earth's surface with a resolution at sea level of at least 100 km.

The use of the truss of the International Space Station (ISS) for the accommodation of several experiments, in the frame of the “Early opportunity for ISS utilization”, will have a lot of advantages such as the possibility of human or robotics intervention, the recovery of the experiment at the end of its life, visual inspection of the items and cost reduction with respect to an installation on a dedicated satellite. However, from the user point of view, the ISS generates a great number of disturbances and severe environmental conditions for the experiments providing constraints and affecting the performances in different areas (thermal, mechanical, and avionics). The present paper will discuss the thermal aspects (disturbances, constraints and performances) concerning three different projects, developed by Alenia Spazio Turin plant, that will be mounted on the truss of the ISS: Hexapod, Coarse Pointing Device (CPD) and Sky Polarization Observatory (SPOrt).

High accuracy measurements of the earth’s gravitational field by satellites are affected by noise due to micro-vibrations caused by the environment and internal sources. In order to derive the best possible gravity field model the effects of non-gravitational accelerations have to be avoided and, where this is not possible, compensated or minimized. Among many other sources of those undesired disturbances are also classical thermal hardware items. This paper describes the development test programme established within the GOCE project to characterize the performance of MLI blankets, which were identified as potential micro-disturbance sources. The outcome of these tests is briefly discussed and the resulting selection of the flight thermal hardware is presented.