|Lost Planet Airmen|
|Directed by||Fred C. Brannon|
|Written by||Royal K. Cole|
|Produced by||Franklin Adreon|
|Cinematography||Ellis W. Carter|
|Edited by||Cliff Bell Sr.|
|Music by||Stanley Wilson|
|Distributed by||Republic Pictures|
Lost Planet Airmen is a 1951 black-and-white American science fiction film produced and distributed by Republic Pictures, which is actually the feature film condensation of their 1949 12-chapter serial, King of the Rocket Men. Lost Planet Airmen was directed by Fred C. Brannon and written by Royal K. Cole and William Lively. The lead actors in Lost Planet Airmen were Tristram Coffin and Mae Clark.
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. Reporter and photographer Glenda Thomas (Mae Clarke) is curious about that secret project. When she tours the Science Associates building, she meets Burt Winslow (House Peters, Jr.), the project's publicity director, and Jeff King (Tristram Coffin), a research project member.
The mysterious "Dr. Vulcan" is intent on stealing the various weapons being developed by the scientists of the Science Associates group. Vulcan hopes to make a fortune by selling these valuable devices to foreign powers. Dr. Vulcan's gang kills one of the scientists. 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. With the assistance of Dr. Millard, he continually foils the attacks by Vulcan's henchmen.
Dr. Vulcan plans on destroying New York City using a sonic ray device, which causes massive earthquakes and flooding. Only "the rocket man" ultimately stands in his way.
Lost Planet Airmen used scenes from King of the Rocket Men, which had been more cheaply made than previous Republic serials. Creating a compilation feature film allowed Republic to have another opportunity to exploit the serial for further profit; the studio's prospects of continuing multi-chapter serials in a waning market was not lost on management. Republic and Columbia Pictures were the last two film studios to offer serials in the mid-1950s. In 1956 Columbia offered only two 15-episode serials; that was the end the cycle. 
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. He further noted (incorrectly) that, "Rocket man is pitted against the sinister Dr. Vulcan in this intergalactic (sic) battle of good and evil".