As helmsman, Sulu pilots the U.S.S. Enterprise during its five-year mission. As third officer, Sulu often takes command in the absence of superior officers.
Nurse Chapel aids Dr. McCoy in ensuring the well-being of crew and others.
James T. Kirk
Arguably Starfleet's best commanding officer, Captain Kirk is the sense of authority in the Enterprise's initial five-year mission to boldly go where no man has gone before.
The voice of Enterprise, Uhura takes charge in coordinating communications to and from the ship.