Potok was one element of the second generation global command and control system (GKKRS) developed according to a decree of 17 February 1976. The first of ten spacecraft was launched as Cosmos 1366 in 1982. These satellites were integrated with the Luch geostationary system and featured retransmission of high rate data retransmission in the centimeter wavelength range. While Luch handled communications between spacecraft and ground stations, Potok handled communications between fixed points and digital data from the Yantar-4KS1 electroptical reconnaissance satellite. Potok was the first communications spacecraft built by the Lavochkin design bureau. The Slav-2 and Sintez transponders aboard Potok were developed by G Ya Guskov at NPO Elas.

Potok was said by one account to have utilized the KAUR-4 spacecraft bus. This had an active 3-axis orientation system, with a single central body from which extended 40 square meters of solar panels. Its basic structure was that of the KAUR-3, but it was equipped with completely new systems: a digital computer, plasma station-keeping engines, hydrazine monopropellant orientation engines, and actively-scanned antennae arrays with 0.5 degrees antenna and 0.1 degree spacecraft pointing accuracy.

Potok transponders utilized a unique, hexagonal phased-array antenna. The principal ground stations for the Potok system were located at Nakhodka and in the Moscow region at Konakovo. From Geyser spacecraft positioned at 80 degrees E and 13.5 degrees W, the Potok system was designed for digital data transmissions in C-band. A third geosynchronous slot at 168 degrees West was never used. Mobile and stationary transmitter/receiver stations were used with antenna diameters of 2.6-3 m as well as compact phased-array antennas. In 1992 Russian officials offered the Geyser-Potok system for commercial international use under the name Sokol.

Typical orbit: 35762 km x 35811 km at .3 to 9.4 degrees inclin. Mass: 2,100 kg (4,600 lb). Associated Launch Vehicle: Proton 8K82K / 11S86, Proton 8K82K / 11S861.

• 1976 February 17 - Energia; Buran; Mir; Luch; Potok approved; N1 formally cancelled. - Launch Vehicle: Energia, N1.

  Central Committee of the Communist Party and Council of Soviet Ministers Decree 'On work on Energia-Buran, DOS-7K nos. 7 and 8, Gamma. Geyzer (Potok), and Altair (Luch) and cancellation of the N1' was issued. The design of an improved model of the Salyut DOS-17K space station was authorised as part of the third generation of Soviet space systems in a decree. At that time it was planned that the two stations (DOS-7 and DOS-8) would be equipped with two docking ports at either end of the station and an additional two ports at the sides of the forward small diameter compartment. Luch and Potok were elements of the second generation global command and control system (GKKRS) deployed in the first half of the 1980's. Luch satellites, analogous to the US TDRS, provided communications service to the Mir space station, Buran space shuttle, Soyuz-TM spacecraft, military satellites, and the TsUPK ground control center. They also served to provide mobile fleet communications for the Soviet Navy. Additional Details: Energia; Buran; Mir; Luch; Potok approved; N1 formally cancelled..

• 1982 May 17 - Cosmos 1366 - Launch Site: Baikonur. Launch Vehicle: Proton. Mass: 2,000 kg (4,400 lb). Perigee: 35,777 km (22,230 mi). Apogee: 35,805 km (22,248 mi). Inclination: 13.70 deg. Period: 1,436.30 min.

  Stationed at 80 deg E. Investigation of outer space; experiments in relaying telegraph and telephone information in the centimetre wavelength range. Positioned in geosynchronous orbit at 80 deg E in 1982-1987 As of 4 September 2001 located at 81.31 deg E drifting at 0.033 deg E per day. As of 2007 Mar 11 located at 68.65E drifting at 0.023E degrees per day.

• 1984 March 2 - Cosmos 1540 - Launch Site: Baikonur. Launch Vehicle: Proton. Mass: 2,000 kg (4,400 lb). Perigee: 35,761 km (22,220 mi). Apogee: 35,807 km (22,249 mi). Inclination: 8.10 deg. Period: 1,436.00 min.

  Stationed at 79 deg E. Investigation of outer space; experiments in relaying telegraph and telephone information in the centimetre wavelength range. Positioned in geosynchronous orbit at 80 deg E in 1984-1988 As of 28 August 2001 located at 75.35 deg E drifting at 0.041 deg E per day. As of 2007 Mar 10 located at 69.92E drifting at 0.020W degrees per day.

• 1986 April 4 - Cosmos 1738 - Launch Site: Baikonur. Launch Vehicle: Proton. Mass: 2,000 kg (4,400 lb). Perigee: 35,712 km (22,190 mi). Apogee: 35,847 km (22,274 mi). Inclination: 5.60 deg. Period: 1,435.70 min.

  Stationed at 13.5 deg W. Continuation of the investigation of outer space; experimental retransmission of telephone and telegraph data in the centimetre band. Positioned in geosynchronous orbit at 14 deg W in 1986-1989 As of 3 September 2001 located at 0.26 deg W drifting at 0.077 deg E per day. As of 2007 Mar 9 located at 55.28W drifting at 0.287W degrees per day.

• 1987 October 1 - Cosmos 1888 - Launch Site: Baikonur. Launch Vehicle: Proton. Mass: 2,000 kg (4,400 lb). Perigee: 35,772 km (22,227 mi). Apogee: 35,804 km (22,247 mi). Inclination: 4.00 deg. Period: 1,436.20 min.

  Stationed at 80 deg E; later moved to 13.5 deg W. Communications experiments. Investigation of outer space; relaying of telephone and telegraph information. Positioned in geosynchronous orbit at 80 deg E in 1987-1990; 14 deg W in 1990-1994 As of 3 September 2001 located at 1.75 deg E drifting at 0.093 deg E per day. As of 2007 Mar 9 located at 68.17W drifting at 0.344W degrees per day.

• 1988 August 1 - Cosmos 1961 - Launch Site: Baikonur. Launch Vehicle: Proton. Mass: 2,000 kg (4,400 lb). Perigee: 35,780 km (22,230 mi). Apogee: 35,796 km (22,242 mi). Inclination: 8.60 deg. Period: 1,436.20 min.

  Stationed at 13.5 deg W; later moved to 80 deg E. Investigation of outer space and relay of telegraph and telephone messages. Positioned in geosynchronous orbit at 14 deg W in 1988-1992; 80 deg E in 1992-1993. In September, 1993, Cosmos 1961 began drifting off station after a mission of five years had apparently been terminated. As of 4 September 2001 located at 80.01 deg E drifting at 0.015 deg W per day. As of 2007 Mar 11 located at 74.58E drifting at 0.039E degrees per day.

• 1990 July 18 - Cosmos 2085 - Launch Site: Baikonur. Launch Vehicle: Proton. Mass: 2,150 kg (4,730 lb). Perigee: 35,785 km (22,235 mi). Apogee: 35,790 km (22,230 mi). Inclination: 1.50 deg. Period: 1,436.20 min.

  Stationed at 80 deg E. Relaying of telegraph and telephone information. Positioned in geosynchronous orbit at 80 deg E in 1990-1994 As of 29 August 2001 located at 71.92 deg E drifting at 0.041 deg W per day. As of 2007 Mar 10 located at 79.57E drifting at 0.022W degrees per day.

• 1991 November 22 - Cosmos 2172 - Launch Site: Baikonur. Launch Vehicle: Proton. Mass: 2,150 kg (4,730 lb). Perigee: 35,776 km (22,230 mi). Apogee: 35,798 km (22,243 mi). Inclination: 0.30 deg. Period: 1,436.20 min.

  Stationed at 13 deg W. Relaying of telegraph and telephone information. Positioned in geosynchronous orbit at 14 deg W in 1991-1995 As of 1 September 2001 located at 7.91 deg W drifting at 0.026 deg E per day. As of 2007 Mar 9 located at 39.91W drifting at 0.204W degrees per day.

• 1994 September 21 - Cosmos 2291 - Launch Site: Baikonur. Launch Vehicle: Proton. Mass: 2,300 kg (5,000 lb). Perigee: 35,774 km (22,228 mi). Apogee: 35,829 km (22,263 mi). Inclination: 4.50 deg. Period: 1,436.90 min.

  Cosmos 2291 quickly moved to 80 degrees E, joining Cosmos 2085 as a replacement for Cosmos1961. Thus, at the end of 1994 the Potok constellation had been restored to its normal 4·sateellite complement: Cosmos 2085 and 2291 at 80 degrees E and Cosmos 1888 and 2172 at 13.5 degrees W. Cosmos 2291 continued at 80 deg E in 1994-1995; then it was moved to 14 deg W in 1995-1999 As of 6 September 2001 located at 62.64 deg W drifting at 0.324 deg W per day. As of 2007 Mar 10 located at 112.35W drifting at 0.417W degrees per day.

• 1995 August 30 - Cosmos 2319 - Launch Site: Baikonur. Launch Vehicle: Proton. Mass: 2,300 kg (5,000 lb). Perigee: 35,775 km (22,229 mi). Apogee: 35,837 km (22,268 mi). Inclination: 3.80 deg. Period: 1,437.10 min.

  Stationed at 80 deg E. Relaying of telegraph and telephone information. Positioned in geosynchronous orbit at 80 deg E in 1995-1999 As of 31 August 2001 located at 16.12 deg W drifting at 0.037 deg W per day. As of 2007 Mar 5 located at 17.95W drifting at 0.052W degrees per day.

• 2000 July 4 - Cosmos 2371 - Launch Site: Baikonur. Launch Vehicle: Proton. Mass: 2,400 kg (5,200 lb). Perigee: 35,770 km (22,220 mi). Apogee: 35,802 km (22,246 mi). Inclination: 1.10 deg.

  Second flight using RD-0210 Phase 2 engines. Geizer military communications satellite. The Blok DM upper stage inserted the Geizer into geosynchronous orbit at 06:20 GMT on July 5. Stationed at 80 deg E. Positioned in geosynchronous orbit at 80 deg E in 2000. As of 6 September 2001 located at 79.81 deg E drifting at 0.014 deg E per day. As of 2007 Mar 10 located at 79.73E drifting at 0.022W degrees per day.