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The ARTEMIS (Advanced Relay and TEchnology MISsion) satellite represents the first element of the Data Relay and Technology Mission Programme (DRTM) developed for the European Space Agency by Alenia Aerospazio (Italy) as the prime contractor. Although using conventional design features and limited mass, power, telemetry and tele-command budgets, the thermal control of the satellite matches the demands dictated by the peculiarities of the ARTEMIS mission such as the significant overall dissipation, the wide spectrum of payload operational scenarios and the relatively unbalanced distribution of payload equipment dictated by system and payload performance considerations. This paper describes the thermal control design solutions with special regard to consideration on ground testability of the system; the analytical approach to predict on-orbit thermal response; the policy adopted in terms of margins and analytical uncertainties.

The ITALSAT telecommunication system is based on the operation of two geostationary satellites: the first (pre-operative) launched in January '91 the second (operative) to be launched in '96. The thermal design of the satellites was extensively verified by analysis and test including a Solar Simulation thermal balance on the structural-thermal model and thermal vacuum - thermal balance on flight models. Additionally, on-orbit temperature data from the protoflight model is available for equinox and solstices 24 hr. transients. The results have been statistically processed and compared with test data and correlation analysis in order to provide a reliable background for thermal control design and verification of future similar telecommunication satellites.

Several last-generation and future satellite communication systems require the use of large deployable antennas. A European product in this field is presently not available: in this frame the European Space Agency assigned a contract for the development of the Large Deployable Antenna Reflector for advanced mobile communications (LDA). The project is driven by ALENIA SPAZIO as prime contractor and system designer with the support of other companies: EGS (Russia), HTS (Switzerland), SENER (Spain), Magna (Austria). The Antenna consists of a paraboloid with 12m in projected aperture, 6.3m of focal length and located with a clearance of 3m from the focal axis. From a technical point of view, the LDA project was characterized by several challenging tasks: thermal aspects are outlined in the paper. In particular, the mathematical modeling of the reflector and the optical characterization of its reflecting mesh required particular care.