Exclusive: Warning! Warning! 50th anniversary ‘Lost in Space’ Blu-ray and book approaching!

Fifty years after the CBS sci-fi series “Lost in Space” blasted into orbit on Sept. 15, 1965, the show’s five surviving stars are still very close. A few gather each year to have dinner to celebrate the birthday of Jonathan Harris, the late actor who played the diabolical and very funny Dr. Zachary Smith.

“We have stayed very much like a normal dysfunctional family,” said Bill Mumy, who played child prodigy Will Robinson during the series’ three-season run.

Baby boomers who grew up watching “Lost in Space” still have a strong connection to the campy show, which boasted a terrific early score from Oscar-winner John Williams, then billed as Johnny Williams.

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“When I do these conventions, people are still so wrapped up in it,” said June Lockhart, who played matriarch Maureen Robinson. “The last time I did one, I said, ‘Excuse me.’ I looked out at the audience and said, ‘I must remind you: It was all pretend!’”

“Lost in Space” was created and produced by Irwin Allen, who went on to make such disaster film classics as “The Poseidon Adventure” (1972) and “The Towering Inferno” (1974).

The series revolved around the Robinson family — John Robinson (Guy Williams), his wife (Lockhart) and their children Judy (Marta Kristen), the brilliant Penny (Angela Cartwright) and Will.

Sent on a five-year mission aboard the Jupiter II with dashing pilot Maj. Don West (Mark Goddard) to explore a planet, they are thrown off course when Smith sabotages the flight, only to get trapped in the ship before he can make his escape.

For the 50th anniversary, 20th Century Fox Home Entertainment is releasing the entire series Tuesday on Blu-ray. Extras include new cast interviews, commentary tracks and a special cast performance of Mumy’s 1980 unproduced script, “Lost in Space: The Epilogue.” (The series also airs on Me-TV and streams on Hulu.)

On Tuesday, Cartwright and Mumy also release a new book, “Lost (and Found) in Space,” which features memories and rare photographs.

For Mumy, Will Robinson was “exactly who I wanted to be when the energy of trying to get inside the TV set struck me at the age of 4,” he said. “It was watching Guy Williams as ‘Zorro’ or watching George Reeves as ‘Superman’ — those two caped superhero guys are who made me just drive my parents crazy. I wanted to be in the TV. Will Robinson was really the fulfillment of that desire.”

Cartwright said the idea of space travel captured viewers’ imagination, and visually the show was “amazing” for its time.

“Paul Zastupnevich, our costume designer, created this Pop art world after the first black and white season,” she said.

Show creator Allen wasn’t a people person.

“He would bang an upside-down tin wastebasket when we were supposed to rock back and forth when the ship was coming in for a rocky landing,” Lockhart said. “He would come on the set and make big pronunciamentos, and I would chuckle at him.”

Kristen didn’t chuckle. As a young actress, she feared him.

“We would be really working hard and trying our best at 9 at night,” she said, recalling one time when she was supposed to say, “little tiny robots.”

“I couldn’t say it,” Kristen said. “Irwin had to come down and yell, ‘Marta, you have to stop this. You have to be serious.’”

Goddard just stayed out of Allen’s way.

“He was like tornado,” Goddard said. “He was really full of fire.”

Lockhart enjoyed her scenes with Williams, who died in 1989. She described him as an “intelligent, educated, charming, funny and elegant man.”

When the series began, public displays of affection were common between Maureen and John Robinson.

“But as time went on, word came down that we were not even to touch each other,” Lockhart said. “It embarrassed the children. We were told even climbing down from stairs or getting out of the space ship, he was not allowed to turn around and take my hand to help me down the steps. They would yell, ‘Cut. Don’t touch her.’ It was nonsense. We did it anyway.”

Bob May, who played the robot, “gave 110% of himself,” Cartwright said. “He was totally into the part.” (During breaks in shooting, the smoke often seen coming out of the robot’s head was May puffing a cigarette.)

As the series progressed, it got campier as Smith began to take center stage.

“Jonathan Harris personally carved that character,” Mumy said, from just a snarling saboteur and murderous villain into “this person the audience loved to hate.”

“He wrote all of his dialogue right from the beginning. He ended up pretty much the star of the show.”

The cast has fond memories of the late actor, Cartwright said. “What a character. Today we still hear his voice. He loved being Dr. Smith.”

Goddard acknowledged that he really wasn’t initially interested in doing the series.

“I wanted to be Paul Newman, not Flash Gordon,” he said. “But it turned out to be a good thing. It was meaningful to a lot of kids. It’s remarkable that so many people when they grew up became engineers, computer experts and even astrophysicists because of this little show they grew up on.”

“Lost in Space,” Lockhart added, “opened up some marvelous opportunities and some lovely contacts.” In 2013, Lockhart became the first actress to receive NASA’s Exceptional Public Achievement Medal.

Maureen Robinson would be proud.

Twitter: @mymackie