Molniya 1-90

Molniya 1/90 was a first-generation Russian communication satellite orbited to test and perfect a system of radio communications and television broadcasting using earth satellites as active transponders and to experiment with the system in practical use. The basic function of the satellite was to relay television programs and long-distance two-way multichannel telephone, phototelephone, and telegraph links from Moscow to the various standard ground receiving stations in the 'Orbita' system. The satellite was in the form of a hermetically sealed cylinder with conical ends -- one end contained the orbtial correcting engine and a system of microjets, and the other end contained externally mounted solar and earth sensors. Inside the cylinder were (1) a high-sensitivity receiver and three 800-MHz 40-w transmitters (one operational and two in reserve), (2) telemetering devices that monitored equipment operation, (3) chemical batteries that were constantly recharged by solar cells, and (4) an electronic computer that controlled all equipment on board. Mounted around the central cylinder were six large solar battery panels and two directional, high-gain parabolic aerials, 180 deg apart. One of the aerials was directed continually toward the earth by the highly sensitive earth sensors. The second aerial was held in reserve. Signals were transmitted in a fairly narrow beam ensuring a strong reception at the earth's surface. The satellite received at 1000 MHz. Television service was provided in a frequency range of 3.4 to 4.1 GHz at 40 w. Molniya 1/90, whose cylindrical body was 3.4 m long and 1.6 m in diameter, was much heavier than corresponding U.S. COMSATs, and it had about 10 times the power output of the Early Bird COMSAT. In addition, it did not employ a synchronous equatorial orbit as do most U.S. COMSATs because such an orbit would not provide coverage for areas north of 70 deg n latitude. Instead, the satellite was boosted from a low-altitude parking orbit into a highly elliptical orbit with two high apogees daily over the northern hemisphere -- one over Russia and one over North America -- and relatively low perigees over the southern hemipshere. During its apogee, Molniya 1/90 remained relatively stationary with respect to the earth below for nearly 8 of every 12 hr. By placing three or more Molniya 1 satellites in this type of orbit, spacing them suitably, and shifting their orbital planes relative to each other by 120 deg, a 24-hr/day communication system could be obtained.