 Zasyadko elaborated a tactics for military use of rocket weaponry.In 1820, Zasyadko was appointed head of the Petersburg Armory, Okhtensky Powder Factory, pyrotechnic laboratory and the first Higher Artillery School in Russia.In 1827, Zasyadko was in charge of Artillery Headquarters of the Russian army and took part in the Russo-Turkish War of 1828-1829, his rockets played important role during siege of Brăila and Varna.