Complex sentence: However, some fans have stated that he was aboard the SDF-3 during the Neutron S missile test, not the science ship Deukalion as stated, and that therefore his fate, like that of the SDF-3, is currently unknown.
Split into simpler sentences: However, some fans have stated that he was aboard the SDF-3 during the Neutron S missile test, not the science ship Deukalion as stated. Therefore his fate, like that of the SDF-3, is currently unknown.