Twelve percent of Russia's orbital missions during 1993-1994 were devoted to the fields of navigation and geodesy, bringing to more than 150 the number of Soviet/Russian navigation and geodetic spacecraft placed into Earth orbit since 1967. By the end of 1994, the Russian navigation satellite network consisted of 25 principal spacecraft in three distinct constellations to service both fixed and mobile subscribers. The geodetic network, on the other hand, includes only 1-2 active spacecraft, two specialized laser reflector satellites, and a larger number of host spacecraft carrying small laser reflectors.
The LEO navigation satellites are launched one at a time by Kosmos boosters from the Plesetsk Cosmodrome into orbits of approximately 960 km by 1,015 km with an inclination of 83 degrees. Each spacecraft has a diameter of 2 m, a height of approximately 3 m and a mass of 800 kg. An internally pressurized compartment housing the primary payload (approximately 0.86 m in diameter, 0.55 m in height, mass of 200 kg) and support systems is surrounded by solar cells affixed to a cylindrical sheet. Electrical power available to the payload is limited to about 200 W average daily (References 439-440). Attitude control is achieved with a 10-m gravity-gradient boom extending from the top of the spacecraft, while payload and telemetry antennas are attached to the bottom, Earth-facing end.
439. Polyot, Omsk, Russia, advertising brochure distributed by the Polet PO, 1990-1991.
440. Russian Spacecraft Design Short Course, Kaman Sciences Corporation, 1994.