 Gene Roddenberry (qv) once hypothesized that the Enterprise  carried a platoon of Starfleet Marines, but they never appeared  onscreen in the original series. The Starfleet Marines would  eventually make an appearance, but not until  _Star Trek VI: The Undiscovered Country (1991)_ (qv) and  _"Star Trek: Deep Space Nine" (1993)_ (qv). The idea was revived  with the addition of a group of "space marines" beginning in the  2003