During the Cold War, the opposing sides threatened each other mainly with nuclear-armed missiles. However, the leaders of the countries that led the opposing blocs and possessed the most powerful arsenals of deadly weapons, namely the USSR and the USA, understood that a possible success in the event of a transition of the war from the "cold" to the "hot" stage is possible only if most of the weapons fired by the enemy missiles will be detected and intercepted in time, and the factor of surprise will be leveled. This is how the concept of “early detection” was born.
The work was carried out on both sides, they were top secret. The very level of readiness of the country to repel a nuclear attack was a state secret no less, and perhaps more, than the number of warheads and their delivery vehicles.
In the USSR, the special Research Institute DAR, headed by General Designer F. A. Kuzminsky, starting in 1960.
When designing the system, the disturbing signal reflected from the ionosphere, which occurs at the time of launch and is generated by a torch, was used as the main factor in detecting hostile missilesnozzle.
By 1970, the experimental radar "Duga", and this is the name of the project, was almost ready and tested on Soviet missiles, scheduled launches of which were carried out from the Baikonur cosmodrome, ships of the Pacific Fleet and ground launchers in the Far East. The radar station showed good performance in conditions of a low level of ionospheric interference. The government decided to build a powerful radar station "Duga" in the Nikolaev region. The place was not chosen by chance, this station could control the space over the entire Black Sea, Turkey, Israel and a significant part of Europe within a radius of 3000 kilometers. How the further foreign policy situation could unfold at that moment, one could only guess.
The Duga over-the-horizon radar was put on combat duty on the day of the 54th anniversary of the October Revolution. Despite the situation of extreme secrecy, it was difficult to completely eliminate the leakage of information, the tracking station was huge, the height of the antennas reached 135 meters, and the length was hundreds of meters. In addition, the Duga radar station created radio interference in the form of pulses resembling a knock, for which it received, almost immediately, the nickname of the “Russian woodpecker” among NATO military countries involved in electronic intelligence. However, some awareness of a potential enemy may have been useful. She restrained excessive arrogance and militancy and cooled the hot heads in the Pentagon, excited by the emergingsuperiority in the number of nuclear charges, as well as the presence of cruise missiles with a flat trajectory "Tomahawk", which were difficult to detect with conventional radars.
The Duga radar was very energy-intensive, so the next two of its samples were mounted near power plants. After the Chernobyl accident, one of them had to be closed for obvious reasons. The low resistance of the received signal at a high level of ionospheric interference prompted the abandonment of the operation of the other two. Their place was taken by a new generation of early detection systems.
