Prognoz

the name of a series of specialized artificial earth satellites used to study solar activity and the effect such activity has on the interplanetary medium and the earth’s magneto-sphere. Prognoz 1 was launched on Apr. 14, 1972; Prognoz 2, on June 29,1972; and Prognoz 3, on Feb. 15,1973. Each was injected from an intermediate earth orbit into a highly elliptical orbit having a maximum distance from the earth (apogee) of 200,000 km and a minimum distance (perigee) of 550 km. The weight of the satellites was 845 kg.

A hermetically sealed housing contained scientific instruments, a telemetry system, temperature-regulating systems, a power supply, and apparatus for solar orientation. Part of the scientific and on-board flight apparatus was mounted on the outer surface of the housing. The scientific apparatus was designed to study solar corpuscular emissions, gamma radiation, X-radiation, streams of solar plasma and their interaction with the earth’s magnetosphere, and magnetic fields in near-earth space. The satellite and some of the instruments were permanently oriented toward the sun.

In accordance with the Soviet-French program of cooperation in the development and investigation of space, French apparatus was installed on Prognoz 2 to study the solar wind, the outer regions of the magnetosphere, and gamma radiation from the sun and to search for neutrons originating from the sun. The studies of all three Prognoz satellites were carried out in accordance with a single program; Prognoz 1 and Prognoz 2 operated simultaneously. The Prognoz satellites continued operating for more than one year.