Walter Koenig , who played Pavel Andreievich Chekov, a key member of the U.S.S. Enterprise on the original “ Star Trek ” series and across the first seven films, has died. He was 90.

As Chekov, a Russian crew member, Koenig spoke in a thick, almost exaggerrated accent and sported a Davy Jones “moptop”. His presence on the bridge was a reminder of Gene Roddenberry’s utopian vision. The original “Star Trek” aired during the height of the Cold War, but it imagined a future in which such regional conflicts had ended in the name of space exploration. Koenig first joined the starship in the show’s second season and would go on to appear in 36 episodes.…