Molniya 1 (Russian: Молния-1) is the first Soviet communications satellite. A total of 5 experimental devices were launched to create a long-distance radio communication line between Moscow and Vladivostok. Later, a series of Soviet and later Russian communications satellites were developed on the basis of the Molniya-1 spacecraft: Molniya-1+ (1967), Molniya-2 (1971), Molniya-3 (1974), Molniya-1T (1983), Molniya-3K (2001). These devices solved the problem of providing long-distance telephone and telegraph communications to remote areas of the Russian Far North, Siberia and the Russian Far East and retransmitting Soviet Central Television channels. For the first time, a digital communication system was used as a means of communication with the satellite. Since 2006, the Molniya satellites have been replaced by more advanced Meridian devices.
History Work on the creation of the satellite began in the Korolev OKB-1 design bureau in 1961 in cooperation with specialists from other design bureaus and institutes. The chief designer of the Molniya-1 space communication system projects (1962), as well as the subsequent Molniya-2 (1965), Korund (1969), and Kulon (1973), was the Deputy Director General for Science at MNIIS, Murad Rashidovich Kaplanov. The initial goal was to create an experimental long-distance radio communication line between Moscow and Vladivostok using Molniya-1. At the same time, it was planned to create an operational radio communication system throughout the Soviet Union and with countries in the northern hemisphere based on Molniya-1 communication satellites in the future. Such a system, combined with local radio relay lines, could ensure the transmission of television programs from the Central Television to all major regions of the USSR. The first launch attempt was made at the Baikonur Cosmodrome on June 4, 1964. Due to an accident in the second stage of the Molniya launch vehicle, the satellite with serial number 2 was lost 287 seconds into the flight. The cause of the accident was a failure of the Block A emptying system, which led to premature depletion of the fuel (kerosene). Without fuel, the turbopump unit went into overdrive, starting to increase its speed beyond the prescribed limit, then the automation issued a command for an emergency shutdown of the propulsion system. The next launch was partially successful - on August 22, 1964, the satellite was launched into orbit as scheduled, but both redundant parabolic antennas did not fully deploy, which excluded its use for its intended purpose. When analyzing the causes of the failure, it was found that during the tests, the insulation of the cables leading to the antenna rod was damaged. This was due to the fact that, according to the instructions of the product designer, the cables were additionally wrapped with polyvinyl chloride tape; no full-scale tests were carried out after this modification. Polyvinyl chloride lost its elasticity at low temperatures and cracked when the antennas were deployed. In the official press, Molniya-1 No. 1 was called Kosmos-41; it existed in orbit for nine months, during which time all systems were tested except for the relay system. There were no other failures, except for the failure of the antennas to deploy. The first successful launch took place on April 23, 1965. Molniya 1 No. 3 was successfully launched into orbit, but it was only possible to turn on the relay after several unsuccessful attempts; the cause was apparently oxidation of the relay contacts in the power supply circuits of the relay or the ingress of a foreign particle into them[3]. Thanks to the work of this satellite, residents of the Far East had the opportunity to watch the May Day military parade of 1965, which took place in Moscow, in real time for the first time. On 30 May the television camera on board Molniya 1 No. 3 captured a full-disk image of the Earth, the first time this had been done. A common problem for the first Molniya-1 series devices was the rapid drop in power taken from the photoelectric converter panels. The reason was the poorly understood influence of the Earth's radiation belts at that time, as well as thermal cycling (at each revolution, the temperature of the solar battery elements changes sharply from +120 °C in the illuminated part of the trajectory to -180 °C in the shade). A total of 7 Molniya-1 satellites were launched, 5 of them successfully. In 1966, due to the heavy workload of OKB-1, the production of the Molniya-1 satellite was transferred to Branch No. 2 of OKB-1, nowadays Information Satellite Systems Reshetnev, and all subsequent satellites of the Molniya series were manufactured at this enterprise.
Purpose The Molniya-1 satellites were intended primarily to create an experimental long-distance radio communication line between Moscow and Vladivostok. Later, the improved Molniya-1+ and Molniya-2 satellites were used to provide telephone and telegraph communications on the territory of the USSR, as well as to transmit Soviet Central Television channels to 20 ground stations with 12-meter antennas (the Orbita system). Thanks to Orbita, by the beginning of 1968, the number of Central Television viewers had grown by 20 million people
Platform
The platform consisted of a cylindrical pressurized compartment with service and relay equipment, on which were attached: six folding solar battery panels, a correction propulsion system shaped like a truncated cone, antennas, external radiators of the thermal control system, actuators and spherical cylinders with nitrogen reserves of the orientation system. The satellite body was oriented with its longitudinal axis towards the Sun, and the antennas, mounted on an external rod, were independently aimed at the Earth. Due to the imperfection of the radio equipment, the active life of the Molniya-1 spacecraft was only about six months, which was significantly improved in subsequent satellites of the series.
Control system
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