Even the most visionary of filmmaking teams can never be certain the movie they're making -- even an adventurous time travel comedy -- will stand the test of time.

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But 30 years after "Back to the Future" first jolted audiences with 1.21 jigawatts of entertainment, some of the key creators behind the enduringly popular film franchise -- screenwriter Bob Gale, cinematographer Dean Cundey and producer Neil Canton, who oversaw production on the entire trilogy -- sat down to reveal just how frequently that time-traveling Delorean came close to never hitting that 88 miles per hour mark.

Spinoff Online: To see the love that audiences still have for this movie, and the high regard that the screenplay being the perfect example of an airtight screenplay -- what has it meant to you over the years?

Bob Gale: All I can tell you is that 30 years ago, if a time traveler from 2015 came back to see Bob Zemeckis and me and say, "Guess what's going to be happening 30 years from now?" We would have said, "What are you drinking -- and could we have some?" I mean, this doesn't happen, right?

At the risk of blowing my own horn, which I don't really want to do, when I was a kid, a little kid, "The Wizard of Oz" would run on TV every Thanksgiving. The family would gather around, and we'd watch "The Wizard of Oz," this brilliant movie that touched everybody and everybody knew the songs. Everybody knew everything. And it's almost like "Back to the Future" has risen to almost that type of status.

What's amazing to me is how kids today, they don't care that the movie takes place in 1985. They don't have a problem with that at all. They love it just as much as kids did 30 years ago. And their parents, who are showing it to them, were those kids.

Where were you and Bob Zemeckis when the seeds were planted in your minds for "Back to the Future?"

Gale: Well, Bob and I had made two movies. We made "I Wanna Hold Your Hand" for Universal. It came out in 1978, and it had flopped at the box office even though audiences loved it. Got wonderful reviews. And then, we made a movie called "Used Cars," which came out in 1980 with Kurt Russell and Jack Warden. And again, the sneak previews went through the roof. Audiences loved it. Some critics loved it, some not so much. But the studio didn't know how to release it, and it was frustrating. We had "1941" in between those two movies, which it did fine at the box office, but it was ripped to shreds [by critics].

We were just trying to do everything we could think of. I mean, our criteria for deciding we want to make this movie was, "We want to make a movie that we want to go see." It was during the summer of 1980 where I got the idea for "Back to the Future." Bob and I had kicked around the idea of doing a time travel movie for years, and we had never really figured out what the hook was.

Actually, I had gone back to my hometown of St. Louis to do some promotion for the summer release of "Used Cars." I'm staying with my folks, and I'm digging around in my dad's basement. I found my dad's high school yearbook. I went to the same high school that my dad went to, and I'd never seen his yearbook before. I'm flipping through it and discovered that he was the president of his graduating class. I'm looking at this picture -- very straight, proper Mark Gale -- and I'm thinking about my class, who was somebody I would have nothing to do with. I'm thinking, these rah-rah political guys. I couldn't stand these type of guys, right? I'm thinking, "Was my dad like that? Was he one of those guys?" If I had gone to school with my dad, what would I have thought of him? And then, I said, "Well, what if you could go to school with your dad? What would that be like?"

I come back to California, and I'm telling this story to Bob. And he says, "Yeah, and what if your mom went to the same high school, and what if it turned out that she was like the high school slut, or something?" We just started cooking on this idea. We pitched it to Frank Price at Columbia Pictures, because even though "Used Cars" didn't do well, the studio loved the movie. They were very happy with it, and Frank was the president of the studio, and he said to us, "When you guys have your next idea, I want to hear it first." So we went into Frank after we cooked this thing up. We told him, and he got it instantly, and it was the easiest development deal we ever set up.

Our first draft of "Back to the Future" was in February of 1981. They asked us for a second draft about six weeks later, and they passed. They said, "Well, it's nice. It's sweet. But we're looking for something more like 'Stripes' or 'Porky's.' Something a little raunchier. We think that that's what people want to see." So they gave it back to us. We turned around, ran around town trying to set this up, and every major studio in town rejected it, either because it was too nice and too sweet. "Take it to Disney. Take it to Disney." Or "Time travel movies don't make any money."

We eventually decided, "Well, what have we got to lose? Let's take it to Disney. What if everybody's right? What if this should be made at Disney?" This was before Michael Eisner had reinvented Disney -- this was the whole last vestiges of the Walt Disney family running the studio. We go in and take the meeting with the executive there, and he says, "Are you guys out of your mind? We can't make a movie like this at Disney. This is a movie about incest. You've got the kid's mother in the car? Oh, God. This is Disney. We don't do that!"

So we racked up over 40 rejections over the years trying to get "Back to the Future" made. After Bob made "Romancing the Stone," and he had a big hit with that, then everybody wanted to make his next movie. And the movie he wanted to make was, thank goodness, "Back to the Future."

And you got it up and running, but you decided that you needed to make a change a few weeks into shooting.

Gale: Yeah, we started shooting with Eric Stoltz, and the comedy just wasn't working out with him. Michael [J. Fox] had always been our first choice, but we couldn't get him out of his TV series, "Family Ties." And so we kept pushing the start date back several times. And then finally, we said, "Well, studio is pushing us to put Eric in the movie." And we thought he would be okay. And we were wrong.

So Bob Zemeckis came to me and to Neil and said, "I think we've got a problem." We looked at some footage, and we said, "Yeah. We've got a problem." And then we turned around and showed it to Spielberg and Frank Marshall and Kathy Kennedy, and they said, "Yeah." Steven wisely counseled us -- he said, "You can't fire him until you get somebody to replace him, because you don't want to shut down the movie. If you shut down the movie, you may not get it started [again]." It's really smart advice.

So we went back to Gary Goldberg, the producer of "Family Ties," begging him, practically, and he said, "Okay. Look. If you guys will agree to shoot your movie around 'Family Ties'' schedule, I'll let Michael read the script and let him decide." We said, "Well, yeah. Of course." So that's how it happened.

How did Michael's presence change everything -- especially his chemistry with Chris?

Gale: It jumped right off the screen. It was immediate.

Neil Canton: It was. And you know what was interesting, was the crew reacted that way. I've always said, "Well, the crew is the first audience of a movie. When they say, ?Hey, how come the guy does that? I don't understand," you should listen, because they're wise viewers. And they immediately reacted "Oh, yeah!"

Gale: There was a sigh of relief. As soon as Michael's first take [was wrapped], everybody went, "Oh, it's going to be okay."

Canton: Yeah: "This is how it's supposed to be."

Gale: Yeah, because before that, everybody was kind of like, "Oh, do these guys know what they're doing?"

Dean Cundey: And also, we didn't have to call Michael "Marty." It was just, like, a nice thing.

Gale: Eric was Method.

Canton: You always had to call him "Marty."

Cundey: He had wardrobe call him -- he wouldn't answer. I'd say, "Excuse me, Eric, could you stand on that… Marty?" "Yes?" "Could you stand over here?"

Canton: I remember when I went and told Chris Lloyd, the night that we made the change. I went to Chris' dressing room, and I said, "I just want to let you know that we're going to replace Eric in the movie, and the new actor's going to be here on Monday." And he looked at me and said, "Well, who's Eric?" And I said, "Well, he's playing Marty." He said, "Oh, well, I thought his name was Marty, and he was just cast as Marty. I didn't realize his name was Eric!"

The film broke all kinds of new ground. How challenging was that for you, Dean, as cinematographer?

Cundey: Movies are always inventing. I mean, a good movie is always one that looks for how to do something new or different. The challenge was how to differentiate between the present -- or now it's the past, I guess -- and the future, which is the present, and the past, which is the past, I guess! And so it was a case of trying to visually cue the audience into the fact that their present was sort of normal-looking. And that the past, the '50s, was very much a sort of nostalgic, warmer, well-remembered time. I grew up in the '50s, so I had an edge on it. I can definitely remember my childhood.

The most difficult co-star, I understand, was the DeLorean?

Gale: Yeah!

Cundey: It's funny, because of our experience of it, but I've seen probably five guys who built beautiful replicas of the thing. And they all have the same experience. They say, "Yeah, all the stuff looks great, but I can't keep it running."

When you knew the movie was a hit, how did it change things for you?

Gale: You have to remember, back then, a wide release was 800 or a thousand screens. We knew the movie was a hit the second weekend when it grossed more than the first weekend. The first weekend, it grossed $10 million, I think. And then in the second weekend, it grossed $11M or $12M. So compared to today's numbers, you don't know how long the movie's going to play. But "Back to the Future" played in theaters -- it was 11 out of 12 weeks of the summer, the number one movie. And it played in theaters until March, 1986 -- not in a lot of theaters by March 1986, but the way movies were released back then was just way different.

Canton: And we never had more than, like, $12 million a weekend. It just would stay within the same, between $11 million and $12 million dollars, all the time. And that was really unheard of, so it was such a different business.

Cundey: When you consider a big opening now, $500 million the first weekend, with a couple of shows recently. It was like, unfathomable, at the time. A hit was one that just stayed around. And 30 years later, it stayed around.

Canton: It's still around. Obviously, Universal wanted to -- all of a sudden, it became sequel talk. And that meant something, because there weren't that many sequels back then. All of a sudden, that meant added pressure and all that, but that's what was kind of uncharted for us.

When did you realize that you'd made a movie for the ages?

Gale: Well, for me, I'm surprised about that, every single day. What's really neat is that the kids who saw the movie, when they were 10, 11, 12 years old, they're now parents, and they're showing the movie to their kids. And their kids love the movie just as much as their parents did when they were kids.

Cundey: To me, it speaks of the -- you can avert your ears if you want, Bob -- the brilliant concept screenplay. The fact that it speaks to, obviously, people of any age, of any type period.

Gale: And all over the world.

Cundey: One of my proudest things about what I do, is the fact that I can go anywhere in the world, and I have, and people have seen "Back to the Future." To me, it's just amazing to be able to have done something like that and have it stay around.

What's it like seeing Michael J. Fox today, and seeing the man he's grown into?

Canton: Well, I mean, I think he's incredibly brave. So many people are diagnosed with an illness fade from the public eye because they don't want people to see them. They want them to remember how they were. The fact that he's out in public, that he's still acting, that he's making fun of it -- like on "Curb Your Enthusiasm," making fun about his disease -- and he's out there with his foundation and trying to help people. I think he's incredibly brave person.

Gale: He's an inspirational guy.

I'm sure that every year, Universal calls up and offers to drive a truck full of money over if you would do a fourth one?

Gale: You know what? They don't, actually. Both Bob and I have said this over and over again -- in fact, at the premiere of "Back to the Future 3," we all wore T-shirts that had the number 4 in it with the circle and a slash, "Back to the Future 4" with a slash through it. So even then, we said, "No. We're done. This is it. These movies are really good the way they are. We're going to be the guys that don't go for the cheap buck. We're going to be the guys that don't go to the well one too many times." We don't want people so say, "Oh, what was the matter with those guys? Didn't they have enough money?"

Cundey: "Didn't they have enough artistic integrity?"

Canton: It's amazing that we are the guys. I have artistic integrity -- who knew?

Cundey: Because I didn't trust you a bit.

Gale: The word, Hollywood and integrity, in the same sentence. [Laughs] That doesn't happen!

I was 16 years old when I saw the movie for the first time --

Cundey: Oh, shut up!

And I remember my reaction. It was like "Somebody made a movie exactly for me." And countless people felt the exactly same way over the years.

Cundey: I think that's what the audience experienced. Who wouldn't want to go back in time and fix something?

Gale: Or be on your parent's first date? Everybody thinks about that.

Canton: Your parents always tell you these stories about when they were your age and how tough it was. But to actually get a chance to experience it...