Beskrivning : The primary function of the Parus satellites is providing location information for the Tsiklon-B navigation system.
The satellites are also reported to be relays for data of the US-P (EORSAT) ocean surveillance satellites and store-dump communication services. With the introduction of the GLONASS (Uragan) navigation system, the relay role may have been the primary function during the last years of operation.
The communication function was later replaced with the Meridian satellites.