Walter Koenig, the actor who played Star Trek’s Pavel Chekov and found another devoted science-fiction audience as Babylon 5’s Alfred Bester, has died aged 90. His agent confirmed the news to ABC News on 26 October.

Koenig joined the original Star Trek in its second season in 1967, playing the young Russian navigator aboard the USS Enterprise. The character was partly intended to attract the youthful following enjoyed by Davy Jones of The Monkees. The haircut helped; the role lasted rather longer than a pop-fashion moment.

He returned as Chekov in seven feature films, from Star Trek: The Motion Picture in 1979 to Generations in 1994. His career also encompassed writing, teaching and a long relationship with the convention audiences who kept the original series alive between screen outings.

Babylon 5 offered a different kind of second act. Creator J. Michael Straczynski wrote the recurring role of telepath Alfred Bester for Koenig, giving him a character whose decisions drove the story rather than simply reporting events from the bridge.

Fellow Star Trek actor George Takei remembered him as “a writer, a teacher, a thoughtful man, and a loyal friend”. Koenig received his Hollywood Walk of Fame star in 2012.