Leonard Nimoy, the Hollywood renaissance man who fashioned a long and prosperous career as the supremely logical and cerebral science officer Mr. Spock from Star Trek, has died. He was 83.

The actor tweeted on Jan. 14, 2014, that he had lung disease. “I quit smoking 30 years ago. Not soon enough. I have COPD. Grandpa says, quit now!!” As he always did, Nimoy signed off with the acronym LLAP, short for “Live Long and Prosper,” his Star Trek character’s most celebrated phrase.

Nimoy died Friday at 8:40 a.m. at his home in Bel Air. His granddaughter, Dani, said on Twitter that the cause of death was end-stage chronic obstructive pulmonary disease.

Nimoy was a vagabond TV character actor when he made his debut as the somber Spock on NBC’s Star Trek, which debuted on Sept. 8, 1966. He went on to play or voice the half-Vulcan, half-human on live-action shows, cartoons, films, video games, etc. all the way through J.J. Abrams’ movie sequel Star Trek Into Darkness (2013) -- marking an amazing span of nearly 50 years.

“For whatever reason, I projected some kind of quality that people said, ‘OK, he’s a good alien,’ ” he told the Los Angeles Times in a 1999 interview.

READ MOREHollywood's Notable Deaths of 2015

In the 1970s, Nimoy replaced Martin Landau in the cast of CBS’ Mission: Impossible series, playing Paris, a master of disguise. And recently, he recurred on the Fox science-fiction drama Fringe as William Bell, the founder of the Massive Dynamic corporation.

His last tweet came on Feb. 22: "A life is like a garden. Perfect moments can be had, but not preserved, except in memory. LLAP"

Leonard Simon Nimoy was born on March 26, 1931, in the West End section of Boston; his father owned a barbershop, and his mother was a housewife. After attending Boston College on a scholarship, he moved west and joined the Pasadena Playhouse troupe. When he was 20, he made his first film appearance, in Queen for a Day (1951).

In 1952, Nimoy ventured into sci-fi for the first time with Zombies of the Stratosphere and had the title role in another film released that year, Kid Monk Baroni, a tale about a disfigured street punk turned boxer.