After completing his seventh grade of school in 1936 he worked at a collective farm until he got a job as a mechanic at a car factory in the city of Dniprodzerzhynsk, where he also attended an aeroclub that he graduated from in 1939.

[1] Immediately after the German invasion of the Soviet Union, Stepanenko was deployed to the warfront as a pilot in the 4th Fighter Aviation Regiment.

[3] In late summer 1942 Stepanenko, Amet-khan Sultan, Aleksey Ryazanov, and several other pilots from the 4th Fighter Aviation Regiment were selected to compose a "free-hunting" group in Stalingrad.

During a dogfight in May he shot down a Bf 109 and a He 111; with the help of his squadron the remaining group of enemy bombers was dispersed and forced to drop their bombs away from the Soviet troops they had previously attacked.

[5] A similar incident occurred in August during a mission to provide cover to Soviet ground troops, during which Stepanenko's squadron encountered a huge formation containing many as 60 enemy aircraft, mostly Ju 88 and He 111 bombers.

[6] Stepanenko was nominated for the title Hero of the Soviet Union for a second time on 28 January 1945; by then, he had flown 395 missions, engaged in 112 dogfights, and personally shot down 32 enemy aircraft.

Having entered the war as an enlisted junior pilot, he was a squadron commander with the rank of major at the end of the conflict.

He graduated from the M. V. Frunze Military Academy in 1949, and then became commander of the 83rd Guards Air Defense Regiment; he then served as a pilot-inspector of fighter aviation combat training from April 1951 to September 1951.