Complex sentence: Aleksei Ledovsky was mentioned as being launched inside a converted R-5A rocket, three more names of alleged cosmonauts claimed to have perished under similar circumstances were Andrei Mitkov, Sergei Shiborin and Marya Gromova.
Split into simpler sentences: Aleksei Ledovsky was mentioned as being launched inside a converted R-5A rocket. Three more names of alleged cosmonauts claimed to have perished under similar circumstances were Andrei Mitkov, Sergei Shiborin and Marya Gromova.