Soviet/Russian Parus satellites

The primary function of the Parus satellites, starting with Cosmos 700, was providing location information for the Tsiklon-B navigation system. It was intended for the use by the Russian navy, particularly by nuclear submarines to increase the accuracy of ballistic missiles launched from the sea. The navigation function was replaced by the GLONASS satellite constellation, but the Parus satellites retained a store and forward communication function.

More Information

Gunter's Space Page

Russian Space Web