 "King of the Rocket Men"'s official release date was June 8, 1949, although this was actually the date the sixth chapter was made available to film exchanges.A 65-minute feature film version, created by editing the serial footage together, was released on July 25, 1951; it was one of 14 feature films Republic made from their serials.The title was changed to "Lost Planet Airmen" after using the working titles "The Lost Planet" and "Lost Planetmen".