(FR2681041-A1)      The space satellite operating in a geosynchronous orbit has a main body (410) containing operational communication equipment and power supplies. Solar panels are located on projecting arms and the orientation is such that a panel (420) is directed at earth. The arms project from the north and south surfaces, and rotate to maintain panel direction following the sun.    The north and south panels have an optical solar reflector as due sections (440, 442, 444) of the west panels. A similar arrangement is provided for the south and east panels. Within the north and south surfaces are heating pipes. The combination of surfaces provide a balance between heat absorption and emission.    ADVANTAGE -   Provides thermally controlled conditions.    (US5372183-A)      A spacecraft, adapted for operation in a low inclination angle earth orbit, comprises north, south, east and west panels defining a spacecraft interior volume. The north and south panels are oppositely disposed with respect to each other and the east and west panels are oppositely disposed with respect to each other. The spacecraft interior volume generally and preferably lacks structural elements that substantially restrict thermal radiation among the panels.    The north and south panels, to which spacecraft equipment is usually mounted, each include conductive heat pipes for reducing the temperature differences across each panel. The exterior surfaces of the north, south, east and west panels have a covering, preferably of optical solar reflectors (OSRs), for radiating thermal energy therefrom, wherein the OSRs have a solar absorptivity that is substantially less than their thermal emissivity. The interior surfaces of the north, south, east and west panels have a covering for effectively radiating thermal energy between and among the panels across the interior volume.    ADVANTAGE -   Avoids heavy network of internal thermally conductive heat pipes to transfer heat from one panel to another.