Ridley Scott, who receives a star on the Hollywood Walk of Fame on Nov. 5, is the first to admit that he’s not especially a man of science. As a schoolboy, his eyes glazed over in math and physics classes: “I was academically a disaster, honestly,” the 77-year-old filmmaker admits, reflecting on a faulty grammar-school education that drove him to the visual arts. “It wasn’t because I was lazy; I’m inherently a multi-tasker, but I could not grasp or retain the information that was coming at me.” Drawing was his gift and his passion: “The saying then was that those who can, do; those who can’t, go to art school.”

That resistance to hard scientific theory endures to this day: When preparing for his blockbusting space drama “The Martian,” he was content to trust the intricate astrophysical research undertaken by screenwriter Drew Goddard and Andy Weir, author of the brainy bestseller at the film’s source. “I used their work as the blueprint — thank God I didn’t have to read science,” he quips.

The irony, of course, is that Scott’s relatively nonacademic approach has nonetheless made him one of cinema’s most visionary world-builders in the heady realm of science fiction, all in the space of just four films. His genre range may have extended from sword-and-sandal epic to feminist buddy movie to urban cop thriller, yet it’s his sci-fi work that arguably accounts for the most indelible and influential images of his career.

In 1979, “Alien” — only his sophomore feature — redesigned the space-travel thriller so vividly, via the now-iconic designs of Swiss surrealist H.R. Giger, that it launched a still-expanding franchise, its DNA present even now in unrelated films and video games alike.

Three years later, Scott returned with “Blade Runner,” a neon-lit, rain-streaked vision of dystopian life on Earth that, even as it adapted Philip K. Dick, has subsequently became a genre touchstone in its own right, referenced by everyone from Spielberg to Japanese anime masters — and now due for a Denis Villeneuve-helmed remake.

Following that double-whammy, it was 30 years before Scott tried his hand at sci-fi again, though he now seems firmly re-entrenched in the zone. “Prometheus,” 2012’s oblique prequel to “Alien,” returned him to the extraterrestrial territory he revisits in “The Martian,” while he and scribe John Logan are revising the script for an as-yet-untitled “Prometheus” sequel — inspired, he says, by Milton’s epic poem “Paradise Lost” — set to start rolling in February.

Did the time feel right for a 21st-century reassessment of the future, or did the projects simply fall into place that way? “I tend to bounce from pillar to post, wondering what I’m going to paint next,” he says, “But this was a call to duty, really, to reexamine and resurrect the Alien, if I could. Its role had been worn out in previous films, but one of the questions that had never been answered was why such a creature would be invented, and by whom. That opens much larger, more universal questions.”

Those questions, he explains, aren’t just scientific but theological: After all, both branches of study come down to a fundamental concern about what lies “out there.” Scott elaborates: “I’ve met a lot of scientists who have whet my appetite for the technical possibilities of the future, but I’ve always wanted to get a group of them together and ask them if they’re religious. Because you’d be surprised how many dyed-in-the-wool astrophysicists there are who say that, yes, they believe in God.

“And I ask them how that relates to the profession of mathematics. Science will say we are random and biological. So if you go further than that, and say you believe in a higher power, are you saying you don’t adhere to the scientific plausibility of why, say, you and I can talk on this phone right now? Or is there a much larger connection that we can’t grasp yet? For me, that’s the biggest question we have left to explore, and that will be the underlying discussion of the next Prometheus film.”

The questions driving “The Martian,” meanwhile, run a little closer to home — literally so, as its core narrative objective involves returning to Earth, not powering into the unknown. Unlike Scott’s previous sci-fi films, there’s nothing speculative about this one: Scott attributes the breadth of its appeal, as evidenced by its sterling B.O. performance, to the fact that it’s “rooted in real science.” How, then, does he define science fiction, spanning as it does the realms of earthly possibility and far-flung fantasy?

Scott admits he’s not sure: “The gap is narrowing between the science fact of it all and the science fiction of it all, and has done so significantly in the last 30 years,” he says.

His films don’t provide concrete answers, but may encourage a more pliable scientific mind-set. He cheerfully recalls the skeptical reaction of famed astronomer Carl Sagan at an early screening of “Alien”: “He came up to me, holding a glass of champagne, and told me it was nonsense, that there would be no aliens in my lifetime or his, or ever.” Six years later, of course, Sagan wrote the novel “Contact,” directly addressing the possibility of alien life.

In any event, Scott warns, perhaps we’ve already let an alien life form of sorts into our homes: In 1984, Scott helmed the landmark “1984” commercial for the then-fledgling Apple Macintosh, but didn’t imagine at the time that personal computers would come to dictate everyday life to such a degree. He credits Stanley Kubrick’s “2001: A Space Odyssey” for being a little more prescient on this front.

“Kubrick didn’t come up with an alien; at least I found that,” he says slyly. “But the powerhouse there was HAL, and that was a brilliant stroke, because no one at that point had thought about computers controlling us all completely. We’re reaching the point of having a perfect intelligent computer that can defeat a chess master in 20 minutes. Once you have a computer like that, one that is fundamentally emotional, the first task you give it is to design another computer, so that they can talk to each other.

“From that moment on,” he concludes with a hint of relish, “we’ll be in dead trouble.”