when did this first satellite construction start?
Somewhere in 1956 or 1957
Sputnik 1
This satellite, named "Object D", was planned to be completed in 1957–58; it would have a mass of and would carry of scientific instruments. The first test launch of "Object D" was scheduled for 1957. Work on the satellite was to be divided among institutions as follows:


Preliminary design work was completed in July 1956 and the scientific tasks to be carried out by the satellite were defined. These included measuring the density of the atmosphere and its ion composition, the solar wind, magnetic fields, and cosmic rays. 
what happened to hungary during the cold war failure of the uprising in Hungary as evidence that the Cold War in Europe had become a stalemate. what is a precursor to hungarian revolution? Both Hungarian and German forces stationed in Hungary were subsequently defeated when the Soviet Union invaded the country in late 1944. what happened during the postwar situation? The Soviet Army occupied Hungary, with the country coming under the Soviet Union's sphere of influence. what is the space initiative of this latter mentioned country of influence? They constructed the first satellite - Sputnik 1, The first cosmonaut Yuri Gagarin was sent to the space
wiki:19663431
Sputnik 1 [SEP] Satellite construction project
The first test launch of "Object D" was scheduled for 1957. Work on the satellite was to be divided among institutions as follows: Preliminary design work was completed in July 1956 and the scientific tasks to be carried out by the satellite were defined. These included measuring the density of the atmosphere and its ion composition, the solar wind, magnetic fields, and cosmic rays. This data would be valuable in the creation of future artificial satellites; a system of ground stations was to be developed to collect data transmitted by the satellite, observe the satellite's orbit, and transmit commands to the satellite.