In 'Star Trek: The Original Series', the starship's helmsman is Hikaru Sulu.
Played by George Takei, Sulu serves aboard the USS Enterprise as its senior helmsman and a lieutenant. He is responsible for steering and maneuvering the ship, working from the iconic bridge console alongside Captain Kirk, Spock, Uhura, and the rest of the command crew.
A common mix-up is Chekov, who is the Enterprise's navigator and later a security and tactical officer. Montgomery Scott—usually called Scotty—is the chief engineer, while Nyota Uhura handles communications. Sulu's role was not completely fixed during development: in the second pilot, 'Where No Man Has Gone Before', he was introduced as a physicist before becoming the regular helmsman.
The character's first name was also a later addition. He was generally called simply 'Sulu' in the original television series, while 'Hikaru' first appeared in Vonda N. McIntyre's 1981 novel 'The Entropy Effect' and was later established in screen canon. Sulu eventually becomes captain of the USS Excelsior.