[2]Professor Millard (James Craven), a scientist who is a member of the group Science Associates, works in a secluded desert location in a cave laboratory on a secret research project.

To stop Vulcan and his operatives, Jeff dons a newly developed, atomic-powered rocket backpack, mounted on a leather jacket, which has a streamlined flying helmet attached that hides his identity.

Only "the rocket man" ultimately stands in his way and unmasks Vulcan, exposing his real identity, while thwarting his diabolical plan of destruction.

Lost Planet Airmen used scenes from King of the Rocket Men, which had been more cheaply made than previous Republic serials.

)[5] Jim Craddock, in VideoHound's Golden Movie Retriever 2001 included a slight mention of the "feature-length condensation of Republic's 12-part science fiction serial, King of the Rocket Man.