Superman IV: The Quest For Peace saw Lex Luthor, who was absent from Superman III, creating The Nuclear Man by taking a strand of Superman’s hair, putting inside a genetic matrix and attaching it to the side of a nuclear missile.
That triggered the creation of Nuclear Man, who was physically portrayed by Mark Pillow and voiced by Hackman.
When that missile went airborne during a test launched, Superman, insistent on ridding Earth of its nuclear weaponry, intercepted the missile and tossed it into the Sun.
The Quest for Peace was met with poor reviews upon release and only made a little over $36 million worldwide off a $17 million budget, thus killing any plans for Superman V. It would be another 19 years until another theatrical Superman movie was released, and Superman Returns, while set in the same continuity as the Reeve series, opted to ignore the events of Superman III and The Quest for Peace.