From the very beginning, Soviet computer technology was employed for military purposes. Lebedev's role as a chief computer designer for the Soviet Union's anti-missile defense system was considered top secret, and his work was shrouded in secrecy. In 1990, sixteen years after his death, Lebedev's participation in the development of the Soviet Union's first anti-missile defense systems was finally revealed in Sovietskaya Rossia [Soviet Russia] newspaper article, August 5 issue, "Money for Defense" by Grigorii Vasilievich Kisunko.

BESM-2, M-20, and BESM-6 enhanced the rapid development of scientific solutions to the most complex anti-missile defense problems in the postwar years. They became the foundation for the huge computing complexes that supported the anti-missile defense systems. Other nations were able to solve the same problems, but many years later. Such military developments were the result of the Cold War, and Sergei Alexeevich could not separate himself from the demands of that time: the backing from the Soviet military greatly improved the economic position of the Institute for Precision Mechanics and accelerated research on universal high-speed computers that would eventually support defense computing centers in the Soviet Union. This was the Institute for Precision Mechanics' main function throughout the Cold War.

Lebedev anticipated all of this. While still in Kiev, he sent a letter to the Ukraine Academy of Sciences Presidium on January 15, 1951:

The Ukrainian Academy of Sciences is developing a prototype of a high-speed computer. This computer will be capable of solving problems with unmatched speed and accuracy. For example, it would be able to solve problems in such areas as intra-atomic processes, jet technology, radar location, the aircraft industry, structural mechanics and others. Tremendous speed and accuracy would enable us to develop missile control devices for accurate targeting through continuous in-flight corrections of guiding missiles' trajectories.

The Ukrainian Academy's Presidium could not support Lebedev's idea because there was no money available for it: Ukraine's national economy was devastated after the Second World War. Moreover, Ukraine's leaders did not understand the computer's importance. After moving to Moscow and becoming the director of the Institute for Precision Mechanics, Lebedev implemented his long-term plan to integrate computing into national defense when the work on the BESM was almost finished. During this period, Sergei Alexeevich mentored the young specialist Vsevolod Sergeevich Burtsev, who had distinguished himself by calibrating the original BESM. Having lost his parents during the war, Burtsev became very attached to Lebedev. Earlier, he had worked at one of Moscow's scientific-research institutes devoted to developing radar systems and applied that knowledge to his projects at the Institute for Precision Mechanics: Between 1952 and 1955, the Institute developed two special computers, Diana-1 and Diana-2, for automatic data reading and radar air target tracking. Subsequent research led to the design and development of a whole generation of computers for use in the anti-missile defense system.

Lebedev appointed Burtsev as his chief assistant, responsible for integrating computers with the defense sector. Sergei Alexeevich's trust in Burtsev inspired the young specialist, who contributed significantly to the M-40 vacuum tube computer. It began operating in 1958 at 40,000 operations per second, several months ahead of the M-20. Soon after, the Institute produced the M-50, which featured floating-point arithmetic. These machines were supplied with a channel multiplexer that enabled them to receive data asynchronously from six directions. The first Soviet anti-missile defense system incorporated them. The government appointed 35-year old Grigorii Kisunko as lead designer of the first soviet anti-missile defense system.

Even though some of the experts laughed at his idea, claiming that shooting down a flying missile with another missile was pure fantasy, Kisunko was undeterred by their ridicule. He firmly believed in the potential of combining the latest radar technology with the new computer technology – the two developing scientific fields that could became the basis of a new defense system. Kisunko headed a group of enthusiasts who developed and substantiated the principles of the anti-missile defense system. Over the course of a year, the group solved several complex problems: How to detect and effectively track small, fast moving ballistic missiles? How to set up automated connections between distant anti-missile defense installations? How to rapidly process data and make appropriate decisions? How to successfully shoot down a target? To solve these problems, they came up with the idea of developing an experimental system – the "System A."

West of Lake Balkhash in the Kazakhstan Republic, a desert area inhospitable to humans stretches out for hundreds of kilometers. Temperatures rise to forty degrees Celsius during the summers, and the only living creatures are poisonous spiders, snakes and scorpions. In 1956, first workers arrived there to begin construction of the Polygon, an anti-missile experimental test site. Manufacturers and military researchers followed, and eventually thousands of people were employed there. The desert became "imaginary Moscow," surrounded by the anti-missile defense system in preparation for a missile attack from Kapustin Yar and Plesetsk.^[15] Workers were supposed to set up the experimental equipment to detect incoming missiles and then shoot them down over the test range, which was unofficially called Sari-Shagan, after the nearest populated area. Everyone worked under wartime-like conditions: builders lived in dug-outs and there was a dire shortage of water. Dust storms were common. Construction on railroad tracks, highways, and electric power lines was carried out simultaneously. A military base was erected along with civilian housing and a research complex, followed by a communication network.

Kisunko, Lebedev, and Burtsev displayed tremendous foresight and courage, even though their task seemed impossible and the vacuum tube computers they depended upon were not always reliable. When Kisunko first viewed the BESM he thought that this "home made" machine would never be mass-produced, so decided to concentrate on the Strela. He signed a contract with SKB-245 to build a special computer for the Polygon based on the Strela, and as a backup made a similar arrangement with Lebedev's Institute. Work continued at the Polygon complex, and a large hall where both machines were supposed to be located was divided into two sections. The general contractor for this project quickly realized that half of the hall allocated to SKB-245 would remain unoccupied, while the M-40 quickly materialized on the other side. Thus the scientists at the Institute for Precision Mechanics were able to demonstrate that they could write scientific papers just as well as solve complex anti-missile defense problems with their M-40 computer, which was based on the BESM.

Within a year, the first successful experimental missile-detection radar system in the Soviet Union was in operation. Two years later anti-missile launch tests commenced, using the fully completed computer-based System A. The system's components were new at that time: high-quality radar, an automatic control system based on the M-40 high-speed computer, fast and maneuverable antimissile devices with precision guidance capabilities and electronic digital coding. Things did not go smoothly at first because some Communist leaders overseeing the project remembered that Kisunko was the son of a repressed kulak.^[16] But eventually, the test day arrived, and everyone remembered for the rest of their lives...

...As soon as the dummy missile was launched, it immediately appeared on the radar locators. Then, the anti-missile launch command was given and the operator pressed the launch button. The instant the target mark became visible on the screen, the anti-missile device was launched. Minutes later, an indicator sign lit up: "Target Destroyed." The following day, recorded footage of the event proved that the anti-missile defense system was indeed successful - the ballistic missile's warhead was completely destroyed.

This event marked a breakthrough in military might, in science, and even in politics: Nikita Khrushchev casually remarked about it at a press conference, "One may say that our missiles can hit a fly in outer space." At the time, many world leaders were not sure whether Khrushchev was serious or not. Other nations had not considered non-nuclear means for destroying ballistic missiles, and Soviet progress in anti-missile defense systems forced the United States to sign the anti-ballistic missile defense system restriction treaty in 1972.

Once, one of Sergei Alexeevich's daughters asked him: "Why do you make computers for the military?" He replied: "To avoid a war."

Behind these accomplishments stands a colossal body of work by many teams of scientists, including the ones Lebedev supervised. They spent a great deal of time at the Polygon. The creators of the first anti-ballistic missile defense system were awarded the Lenin Prize. Among them were Kisunko, Lebedev, and Burtsev. Their vacuum tube machines employed at the Polygon were eventually converted to semiconductor computers. One of them was a three-processor computer that performed 1.5–2 million operations per second. This was the first Soviet computer based on integrated circuits. Eventually Soviet scientists and engineers oversaw the development of a reliable, miniature multi-purpose computer that took up only 2 1/2 cubic meters. The experience of building the first third-generation computer served as the base design of the Elbrus* supercomputers.^[17]

^[15] Editor's note: Kapustin Yar and Plesetsk were top secret Soviet missile bases.

^[16] Editor's note: Kulaks were landowning peasants who, in the 1930s were brutally repressed, arrested, and stripped of their land and societal status by Stalin.

^[17] Elbrus is the highest mountain in the Caucasus and Lebedev was an amateur mountain climber.