Abstract: A method and an arrangement for the employment of free space transmission systems for interruption-proof links between individual satellites of satellite communications systems by utilizing optical terminals. The communication link between two satellites is established in a reliable manner despite the presence of microvibrations.

Abstract: In order to achieve a considerable reduction of the outlay required on the ground in connection with the accurate calculation of the exact orbital position of each individual satellite of a constellation, first the exact orbital position of a preferably central master satellite of a sub-group of satellites embodied as a special formation is determined. This calculation is performed autonomously on board the satellite by means of customary measurements supported from the ground, or respectively by means of GPS, MANS, etc. Then the exact position of all other satellites in the same formation is determined from range and pointing data, which are provided by each IS link terminal. These pointing data are well known after the establishment of the inter- satellite link and are continuously updated.

Abstract: The instant invention comprises a method and arrangement for station keeping a geostationary satellite cluster, employing an optical intersatellite connection constituted of a number of satellites (14F to 14K), which are located in a common, limited area, for example 0.1, on the geostationary orbit. In this case the position of the satellite cluster is determined by the temporarily selected master satellite (14J), which receives its correction commands via a ground station (17) and which sees to it that such corrections are simultaneously performed by the remaining satellites of the cluster.