The design for the Mayak spacecraft closely resembled the Arcos geosynchronous spacecraft with which it was to form the Marathon communications system. The total on-orbit mass was to be 2,500-3,000 kg which included a payload mass of 580 kg. Mayak would support both L-band and C-band communications and would be compatible with INMARSAT standards. Four spacecraft would comprise the Mayak system and the design lifetime for each vehicle was to be twice that of Molniya: 5-7 years. The first launch of a Mayak spacecraft by the new Rus launch vehicle was not scheduled until 1997 or later, five years after the original schedule.
Gross mass: 3,000 kg (6,600 lb).
Payload: 580 kg (1,270 lb).