Star Trek: The Original Series the 23rd century bearing a crew dedicated to exploring the Milky Way Galaxy. Roddenberry noted a number of influences on his idea, some of which includes A. E. van Vogt's tales of the spaceship "Space Beagle", Eric Frank Russell's "Marathon" series of stories, and the film "Forbidden Planet" (1956). Some have also drawn parallels with the television series "Rocky Jones, Space Ranger" (1954), a space opera which included many of the elements that were integral to "Star Trek"—the organization, crew relationships, missions, part of the bridge layout, and some technology. Roddenberry also drew heavily from C. S. Forester's Horatio Hornblower
Star Trek: The Original Series and the Vulcan salute, as well as a re-airing of the TOS episode "Space Seed". <onlyinclude> </onlyinclude> The show's theme tune, immediately recognizable by many, was written by Alexander Courage, and has been featured in several "Star Trek" spin-off episodes and motion pictures. Gene Roddenberry subsequently wrote a set of accompanying lyrics, even though the lyrics were never used in the series, nor did Roddenberry ever intend them to be; this allowed him to claim co-composer credit and hence 50% of the theme's performance royalties. Courage considered Roddenberry's actions, while entirely legal, to be unethical. Series producer Robert Justman noted