He was the son of Augustyn Träger, who was also active in espionage against the Germans. Roman's biggest accomplishment was the compilation of reports about the German factory and testing facility of V-1 and V-2 rockets on the island of Usedom. After these reports were given to the Polish Armia Krajowa (Home Army), who in turn passed them on to British intelligence in London, the Allies bombed Peenemünde in Operation Hydra in 1943, killing two V-2 rocket scientists and delaying V-2 test launches by seven weeks.