Sci-fi writer, George Clayton Johnson, has passed. He wrote the 1st episode of <a href="https://twitter.com/hashtag/StarTrek?src=hash">#StarTrek</a> <a href="https://t.co/RZCx5OjIYv">https://t.co/RZCx5OjIYv</a> <a href="https://t.co/Ck9TTgQ9wk">pic.twitter.com/Ck9TTgQ9wk</a> —@thenewstarship George Clayton Johnson, the legendary science-fiction writer who authored the first Star Trek television episode and several classic stories for the popular 1960s TV show The Twilight Zone, died on Christmas Day. He was 86.

Johnson, who also co-wrote the dark futuristic tale Logan's Run, died of cancer in Los Angeles on Friday, his son, Paul B. Johnson, told The Associated Press.

"Please emphasize how much he loved his fans, and judging by the overwhelming response I've received, from hundreds of people, known and unknown, he made quite an impact on them," said his son, who has been deluged with calls, emails and social media postings in recent days.

Although not widely known outside of science-fiction circles, Johnson was revered among fans of the genre for his work, which also included collaborating with Ray Bradbury on the 1962, Oscar-nominated, animated short film Icarus Montgolfier Wright.

Judging by the overwhelming response I've received, from hundreds of people, known and unknown, he made quite an impact on them. - Paul B. Johnson said about his late father George Clayton Johnson

A popular figure at science-fiction conventions for decades, the soft-spoken but friendly author was instantly recognizable for his long, flowing white hair and beard, as well as what might best be described as his hippie attire.

"He is not one of those guys who uses his celebrity as such," his son had recently told the AP. "He'll give the same attention to a young aspiring writer who wants to know how to get into the business as he would a famous producer he knows or someone he was friends with like Ray Bradbury."

Johnson's best-known science-fiction work was likely Logan's Run, co-written as a novel with William F. Nolan in 1967 and released as a film in 1976.

The dystopian story envisions a futuristic society in which young people live idyllic lives inside an enclosed dome but with one catch — they are executed when they turn 30.

One of them, Logan, is a so-called "sandman" whose job is to track down and kill those who attempt to avoid their ritualistic executions. His superiors, curious why the others want to run away, falsify his personal records, advancing his age to 29, then send him off to find those who don't return.

The book was adapted into an Oscar-nominated film starring Michael York as Logan and Jenny Agutter as a fellow runner. It also included a brief but memorable appearance by a young Farrah Fawcett.

It was followed by a short-lived TV series, and for years there has been talk of a remake.

Before Logan's Run Johnson also created several of the best episodes of The Twilight Zone.

One that dealt poignantly with aging was Kick the Can, in which a group of elderly rest-home residents turn back their biological clocks and relive their childhoods by playing that simple children's game. The story, which first aired on television in 1962, was retold in 1983's Twilight Zone: The Movie, in a segment directed by Steven Spielberg.

In another Twilight Zone episode, titled A Game of Pool, Jonathan Winters is the late Fats Brown, the greatest pocket billiards player who ever lived, and who comes back to life to challenge Jack Klugman's upstart young hustler who boasts he could have beaten him. When Klugman's character does win he's forced to spend his eternity defending the title from other young upstarts while Winters' character goes off fishing.

Nothing in the Dark which starred a young Robert Redford as a kindly version of the Grim Reaper, was one of Johnson's favorite stories, according to his son. In it Redford's character has arrived to take an elderly woman, but he doesn't reveal himself until he's assured her that death is nothing to fear.

Johnson's most prominent mainstream work was Ocean's 11, the 1960 film about a Las Vegas casino heist that starred Frank Sinatra and his Rat Pack buddies Sammy Davis Jr., Dean Martin and Peter Lawford. He and fellow writer Jack Golden Russell created the story, which has resulted so far in a remake and two sequels, each starring Brad Pitt and George Clooney.

In 1966, Johnson wrote The Man Trap, the premiere episode of Star Trek that introduced audiences to the crew of the USS Enterprise, including now familiar characters Capt. James T. Kirk and Mr. Spock.

Born July 29, 1929, in Cheyenne, Wyo., George Clayton Johnson served in the Army before studying drafting in college.

He eventually moved to Los Angeles where he worked as a draftsman for the Lockheed aviation company while moonlighting as a writer.

Soon after quitting his day job to pursue writing full-time, he connected with another prominent Twilight Zone writer, Charles Beaumont, who introduced him to the show's creator, Rod Serling.

Over the years Johnson also had a handful of small roles in quirky films such as The Intruder, which starred William Shatner, The Boneyard Collection and Her Morbid Diaries. His last film appearance was in 2013's Saint Bernard.

In addition to his son, Johnson is survived by a daughter, Judy Olive, and his wife, Lola Johnson.