Quantum Leap is an American science fiction television series that originally aired on NBC for five seasons, from March 1989 through May 1993. Created by Donald P. Bellisario, it starred Scott Bakula as Dr. Sam Beckett, a physicist who leaps through spacetime during an experiment in time travel, by temporarily taking the place of other people in order to correct historical mistakes. Dean Stockwell co-stars as Admiral Al Calavicci, Sam's womanizing, cigar-smoking companion and best friend, who appears to him as a hologram.