Prognoz (US-KMO, 71KH6)

Prognoz (artist impression)

Early warning satellites of the second generation were developed as part of the US-KMO (Prognoz) system, which was supposed to complement and then replace the US-KS (Oko) space-based early warning system. Development of the US-KMO system began in 1979. In contrast to the first-generation system, which was designed to detect only launches of ICBMs from bases in U.S. territory, the US-KMO system was designed to provide coverage of SLBM launches from oceans as well.

The most important distinguishing feature of the second-generation satellites was their look-down capability. These satellites were to be deployed in geosynchronous orbits, from which they could provide coverage of most of the oceans. It is likely that these satellites are supposed to replace the US-KS (Oko) first-generation satellites in HEO orbits as well. Deployed in highly elliptical orbits, second-generation satellites could provide coverage of polar regions in addition to the coverage of U.S. territory and the oceans.

Details of the US-KMO (Prognoz) system architecture are unknown, but it seems that the system in its full configuration would include up to seven satellites in geosynchronous orbits and about four satellites in highly elliptical orbits. All satellites are supposed to have the capability of detecting launches of ballistic missiles against background of Earth surface and cloud cover.

It is difficult to determine whether a specific satellite in geosynchronous orbit is a first-generation US-KS (Oko) or a second-generation US-KMO (Prognoz) satellite. 

The number of satellites that are believed to be second-generation early warning satellites is too low to draw any conclusions about their operational lives. The longest-living second-generation satellite, Kosmos-2224, was operational for 77 months, setting a longevity record for all early warning satellites. Kosmos-2133 worked for 56 months and Kosmos-2209 for 50 months, which probably mean that their operations were successful. Kosmos-2282 ceased operations after 17 months, most likely because of a malfunction. Kosmos-2350 ceased all maneuvers only after two months of work, which also indicates a failure. Kosmos-2379, launched in August 2001, continues to work.