The MESM, or Small Electronic Calculating Machine, was developed in the Soviet Union under the leadership of Sergey Lebedev starting in 1947. The project was initiated to address complex differential equations required for restoring the national power grid and calculating ballistic missile trajectories.
The machine was housed in Feofaniya, near Kyiv, in a building that previously served as a monastery dormitory and a psychiatric hospital. Development continued through the late 1940s, with Lebedev balancing his work on the MESM in Kyiv and the BESM-1 project in Moscow after his 1950 transfer.
Following a secret government decree signed by Joseph Stalin on August 1, 1951, the team was mandated to complete the machine. On December 25, 1951, a commission led by Mstislav Keldysh officially accepted the MESM into permanent operation.
Technically, the MESM utilized 6,000 vacuum tubes and operated at a speed of 50 operations per second. It featured a binary system with fixed-point arithmetic, 16-bit data representation, and a magnetic drum capable of storing 5,000 codes.
The computer remained in service until 1957, when it was transferred to the Kyiv Polytechnic Institute for educational purposes. By 1959, the machine was dismantled and disposed of, with only a few components surviving in the Foundation for the History and Development of Computer Science.
