 Born into a family with a distinguished military past, Kasatonov studied at naval institutions in Leningrad and on the Black Sea, before joining the navy's Northern Fleet.Much of his early service was spent aboard the heavy nuclear missile cruiser "Kirov", rising through the ranks to eventually serve as her assistant commander.During his time with the ship he served through search and rescue operations for two Soviet submarines, the "K-219" in 1986 and the "Komsomolets" in 1989.