Molniya
 |
Molniya-2 |
Russian communications satellites;
"Molniya" means "lightning". All move in highly elliptical,
12-hour orbits, with perigees (low points) of no more than a few hundred
kilometers and apogees (high points) of up to 40,000 km. Such orbits, that
have become known as Molniya-type orbits,
require less rocket power to achieve than a geosynchronous
orbit and are better suited to communications with northern latitudes.
The first flights of the Molniya-1 series, in 1964-65, tested the satellite
for use in military command and control. In 1968, a complete constellation
of Molniya-1s became operational within the Soviet armed services. This
constellation, like that of all subsequent Molniyas, consisted of four pairs
of spacecraft with orbits inclined at 90o to one another, replenished as
necessary. Flight trials of Molniya-2 took place 1971–74 and operational
flights in 1974–77. Molniya-2 was used in the Orbita television system
and also for the military Korund communications system. Development of Molniya-2M,
later renamed Molniya-3, began in 1972 and flight trials in November 1974.
The Molniya-3 was used to create the Orbita communications system for northern
regions, and later versions were incorporated into the Unified System of
Satellite Communications (YeSSS). All Molniya satellites have masses of
1,500-1,800 kg and have been placed in orbit by Molniya
8K78 launch vehicles, mostly from Plesetsk but also from Baikonur.
Related category
SATELLITES
AND SPACE PROBES
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