Abstract: For exchange of information between an earth-station and a satellite in geostationary orbit, information signals addressed to the satellite are transmitted from the earth-station, and information signals from the satellite are received at the earth-station. Signals addressed to the satellite and the signals from the satellite have a common first carrier frequency. Signals addressed to the satellite are transmitted to an intermediate satellite with an angular offset from the satellite in geostationary orbit. The intermediate satellite retransmits signals laterally to the geostationary orbit satellite on a second carrier frequency different from the first carrier frequency.

Abstract: The two-liquid propulsive system for an artificial satellite is characterized in that the components of the propellant are unequally distributed in at least two pairs of tanks (12, 16) and (14, 18) which are associated in such a way as to provide additional fuel in a first pair of tanks and additional oxidizer in a second pair of tanks, and in that the different pairs of tanks are suitable for being used in succession during predetermined time periods so that the exhaustion of a first propellant component in one tank (14 or 16) indicate that the residual normal lifetime of the satellite is at best approximately equal to said predetermined time period, and that after exhaustion of the second propellant component in the tank (16 or 14), the two tanks (12 and 18) each containing an excess quantity of one of the propellant components are associated in order to extract the satellite.

Abstract: The invention relates to a support for at least one photovoltaic cell, comprising at least one block made of heat-conducting material with which said cell is in close thermal contact. According to the invention, this support comprises at least one tube the wall of which may be traversed by the heat, said tube being fastened to said block, in thermal contact therewith, and closed at its end to define a closed cavity inside which an evaporable and condensable fluid is enclosed. The invention is particularly applicable to a solar generator.

Abstract: The present invention relates to a solar generator for producing electrical energy from solar energy, mounted in particular on board an artificial satellite and constituted by a plurality of pivoted panels, stacked but unfoldable, each of which comprises a thick frame inside which is disposed a thin flexible support carrying solar cells, said frame comprising intermediate stiffeners connecting two opposite sides of the frame, wherein each panel comprises, between two intermediate stiffeners and between the end intermediate stiffeners and the sides of the frame there-opposite, a plurality of wide, flat auxiliary stiffeners, transverse with respect to the intermediate stiffeners and on which said flexible support is fixed at least partially.