Space Sentinels (originally titled The Young Sentinels and renamed midway through its only season) is a Saturday morning animated series produced by Filmation which debuted on the American NBC network on September 10, 1977 and ran for thirteen half-hour episodes. The series has been called "ahead of its time" due to its racially diverse cast of main characters. In this series, the Roman mythological figures Hercules and Mercury are joined by Astrea, a character created specifically for the series, to form a superhero team to protect mankind.